Speech Background Noise

This study aims to fill the gap between the endless possibilities of the parametric design process and the detailed acoustic analyses. The developed methodology consists of a custom parametric algorithm that explores the variations of possible interior implementations based on material properties, geometrical formations, and positions in the room to optimize the acoustic response of the space. The proposed methodology assists the design process in the very early phase and explores diverse options. In the first stage, all variations are evaluated in Pachyderm for rapid feedback and to reduce the possibilities for further analysis. The second stage was a detailed evaluation of the first design selection in Odeon and the selection of the best design proposal from the generated. The implemented parametric approach is described, and the final approved design evaluations are presented.

Sound-absorbing barriers and screens are commonly employed to mitigate one of the most annoying noises in workplaces: intelligible speech. However, isolating their acoustic contribution from all the other elements (ceilings, wall treatment, or carpets) is challenging. This study uses a wave-based room acoustic modeling approach to explore the acoustic function of desk screens in a virtually reconstructed open-plan office. Analytical models, finite-element simulations, and experimental data from 3D-printed samples allowed defining a multi-resonator unit cell, attenuating the voice signal’s main formants. The sound-absorbing panels composed of the unit modules iteration are assessed in the full-scale digital model, starting from the calibrated version on in-field measurements. The wave-based engine employed in this study grants the crucial aspect of computing the acoustic performance of the potential multi-resonator screens, including the edge diffraction due to their desk installation. In the virtual workplace, the acoustic role of such screens in increasing the speech level decay is outlined in comparison with the calibrated scenario and the traditional screens’ option.

This paper presents a development of software for the measurement and estimation of the quality of acoustic design in open-plan offices. The measurement method is defined by a standard and measurements should be performed in a large number of different spatial positions in order to measure and determine the acoustic quality of the surroundings of as many workstations as possible. The presented software significantly simplifies the process of analyzing open-plan offices by processing the signal at the time of measurement. Furthermore, it allows for the storing of measured signals and parameter values, which can be of importance for further analysis or repeated calculations. The presented procedure leads to the reduction of the necessary hardware elements for completing the analysis. All that is needed for measurement are a sound source, a microphone, a sound card and a computer. As a result, the user obtains a detailed report of the characteristics of the analyzed office space and a descriptive mark which depends on the values of the calculated parameters.

Based on the clarity of speech for educational facilities. This research was carried out on adapting the field survey to determine the architectural and acoustic measurements, followed by a digital simulation using CATT for both rooms. Sustainable treatments were provided to improve the sound environment of the learning process and were again tested using CATT. Analysis and simulation indicate that both rooms suffer from poor acoustics due to the surrounding area and the finishing materials selection. One possible solution to this problem is to use a new sustainable absorbent to maximize uptake, reducing excessive reverberation time to acceptable values, increasing early reflections and eliminating shadow areas that improve speech clarity for all receivers.

There is a growing scientific consensus that COVID-19 could be transmitted through the airborne route, putting ventilation at the heart of a mitigation strategy for buildings, including schools. The design of suitable systems requires to consider all aspects both for the control of air movement and the diffusion of bacterial loads, but also of other parameters of indoor air quality. This work examines the acoustic design of ventilation systems in schools and the effects that the systems have on the acoustic quality of the classrooms in compliance with the standard series UNI 11532. The standards provide a guideline on the design and the evaluation of the acoustic performances of schools, including attention for children with special educational needs. In particular, the case study refers to classrooms in the University Politecnica delle Marche, Ancona

The measurement methods presented in standard ISO 3382-3 have been suggested for evaluation of acoustics in open-plan learning spaces. This means that there should also be a suitable design method to ensure the acoustics beforehand. The purpose of this study is to find out whether the results of the measurements carried out in recently built open-plan learning spaces correspond to the results of room acoustic modelling performed in design phase of the spaces. Measurements were done in five new open-plan schools. The results show that room acoustic modeling can be used as a design method for open-plan learning spaces.

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ISO 3382-3 is globally used to determine the room acoustic conditions of open-plan offices using in situ measurements. The key outcomes of the standard are three single-number quantities: distraction distance, rD, A-weighted sound pressure level of speech, Lp,A,S,4m, and spatial decay rate of speech, D2,S. Quantities Lp,A,S,4m and D2,S describe the attenuation properties of the office due to room and furniture absorption and geometry. Our purpose is to introduce a new single-number quantity, comfort distance rC, which integrates the quantities Lp,A,S,4m and D2,S. It describes the distance from an omnidirectional loudspeaker where the A-weighted sound pressure level of normal speech falls below 45 dB. The study explains why the comfort criterion level is set to 45 dB, explores the comfort distances in 185 offices reported in previous studies. Based on published data, the rC values lie typically within 3 m (strong attenuation) and 30 m (weak attenuation). Based on this data, a classif...

This thesis consists of seven publications that presented results of room acoustic research studies. Room acoustic measurement and prediction methods for work spaces are studied. Measurements are made in industrial workrooms, open-plan offices and two significantly different laboratory spaces of Finnish Institute of Occupational Health, Turku. This thesis presents a new room acoustic measurement method for open-plan offices. The method is published in ISO 3382-3:2012 standard. The method is developed from a method originally used in room acoustic measurements of industrial workrooms. An omnidirectional loudspeaker and wide band noise signal are used to measure spatial decay of sound pressure level (SPL) of speech from one workstation to other workstations on a measurement line. SPL of masking sound and speech transmission index (STI) are also measured in the workstations. The measurement results are used to determine single-number quantities: spatial decay rate of the A-weighted SPL of speech, D 2,S , the A-weighted SPL of normal speech in the distance of 4 m from the speaker, L p,A,S,4m , and distraction distance, r D. Target values are determined for the single-number quantities. They are based on the distribution of measurement results in Finnish open-plan offices. Simple prediction models are developed for D 2,S and L p,A,S,4m. The models are based on linear regression analysis of empirical data from 16 different open-plan offices. The effect of room acoustical changes on spatial decay of speech in open-plan offices can be estimated using these simple models. A procedure to calculate STI using the simple models and to determine r D is described. The predicted single-number quantities are compared to measured quantities in 26 open-plan offices. The effect of room acoustic changes on STI and spatial decay of speech is studied in two series of laboratory experiments. The first study focuses on two adjacent workstations in a test room where all the walls are sound-absorbing. The effects of ceiling, floor and screen absorption, screen height, room height and masking sound level are investigated. The second study examines the effect of ceiling, wall and screen absorption, screen height and masking sound level on the A-weighted SPL of speech, the spatial decay rate of speech and STI in an open-plan office laboratory with 12 workstations. The laboratory experiments provide measured evidence on the effects that typical room acoustic changes cause to SPL of speech and STI in open-plan offices. The effect of ceiling, wall and screen absorption, screen height and SPL of masking sound are studied exhaustively. The results emphasize the importance of all-inclusive design of room acoustics in open-plan offices.

Open-plan office is a room designed without the use of full-height partitions to isolate a workstation from other workstations. Speech privacy is one of the acoustical problems related with communication activities of the workers. Previous studies have shown that there are several sound phenomena that were unable to be explored using computer simulation based on ray tracing method. This paper is attempted to find the influence of partition height of various designs to the privacy level based on computational fluid dynamic, especially using the acoustics diffusion equation method. The results show that variation of height partitions can lower sound pressure level value by 5%-6%, variation of absorption coefficient can lower SPL value by 8%-9 %, and adding furniture as book shelves does not change the open-plan office privacy level significantly.

The measurement of the Sound Strength (G) room acoustic parameter requires a calibration of the measuring system, so either the sound power of the source or the sound pressure level at a distance of 10 m in free field is known. Two procedures are described in ISO 3382-1: Calibration in a reverberation chamber and calibration in free field in a large anechoic chamber. Both methods require that all conditions in the measuring chain (amplification gains, sound card, cables etc.) remain fixed during calibration and in-situ measurements. This can be impractical mainly because measurements may be performed much later than calibration and at a distant location, and it cannot be guaranteed that the conditions in the measuring chain remain unchanged. In this paper a Two-step calibration procedure is proposed that removes the requirement of fixed conditions of the measuring chain. The procedure adds a second step to the normal reverberation room or free field calibration methods, in order to ...

There is a growing scientific consensus that COVID-19 could be transmitted through the airborne route, putting ventilation at the heart of a mitigation strategy for buildings, including schools. The design of suitable systems requires to consider all aspects both for the control of air movement and the diffusion of bacterial loads, but also of other parameters of indoor air quality. This work examines the acoustic design of ventilation systems in schools and the effects that the systems have on the acoustic quality of the classrooms in compliance with the standard series UNI 11532. The standards provide a guideline on the design and the evaluation of the acoustic performances of schools, including attention for children with special educational needs. In particular, the case study refers to classrooms in the University Politecnica delle Marche, Ancona

One of the most used intelligibility's parameters is Speech Transmission Index : the techniques for determining it employ an artificial speaker and listener. When signal to noise ratio is particularly low, for example inside cars, the value of STI is mainly influenced by this ratio and measuring the emission level of real speakers is the only way for driving correctly the artificial mouth. We have implemented a technique that is based on a throat-activated microphone and it is able to find the effective level of a real speaker's voice inside a noisy space in realistic conditions. We have studied especially the speech level inside cars and we have discovered how the value defined by IEC/ITU standards may be extremely different from real one. In this way, we were able to produce test signals at a more appropriate emission level.

The Modulation Transfer Function (MTF) is used in room acoustics as a descriptor of the effectiveness of transmission down the signal path, between the speaker and listener. A major application for this has been speech intelligibility. Basis for MTF analysis is the signal to noise ratio. Noise can be any sound masking effect, steady state noise, transient noise of reverberation or apparent noise due to adjacent octave sound levels.

Room acoustic parameters of open-plan offices, e.g. ceiling, wall, screen, and furniture absorption, and screen height between workstations, affect strongly sound pressure level (SPL) of speech. The effect depends on the distance from the speaker. The aim of this experimental study was to examine the effect of ceiling, wall, and screen absorption, and screen height on the spatial decay of speech both at short and long distances from the speaker. Twenty-two experimental conditions were built in an open-plan office including 12 workstations. The conditions were combinations of ceiling absorption (2 levels), wall absorption (2 levels), screen absorption (2 levels), and screen height (4 levels). The spatial decay of Aweighted SPL of speech was measured according to ISO 3382-3 in workstations at distances from 2 to 9 m from the speaker. The A-weighted SPL of speech in the nearest workstation, at the distance of 2 m, varied between 53 and 61 dB, and at the distance of 4 m, between 46 and 60 dB. The spatial decay rate of A-weighted SPL of speech, D 2,S , varied between 1.3 and 8.5 dB. The results confirmed that ceiling absorption is the most efficient way to increase spatial attenuation, but the attenuation effect also depends on the absorption of vertical surfaces like screens and walls, and the height of the screens. Our study is unique because it is the first experimental study conducted in a full-scale open-plan office, which investigates the impact of several sound absorbing surfaces and screen height simultaneously.

Background. Speech is the most disturbing noise source in open-plan offices. The disturbance can be reduced by e.g. sound-absorbing materials, masking sound and screens between workstations. An additional reduction in speech levelcan be achievedbye.g. partially enclosed workstations, pods, sofagroups and chairs, and fully enclosed booths. However, there is no standardized method to declare the sound reduction properties of such ensembles. Aim. Our purpose wastointroduce anew method to determine the sound reduction of furniture ensembles. The second aim wastodemonstrate which physical parameters affect the sound reduction. Materials and Methods. The test consists of twosuccessive sound power levelmeasurements in areverberation room. The sound reduction is defined as the leveld i ff erence without and with the furniture ensemble when a loudspeaker is placed in the occupant'sposition inside the furniture ensemble. Asingle-number quantity,speech reduction index, D S ,isdefined as the difference of the A-weighted sound power levels when the loudspeaker's power is normalized to the standardized speech spectrum. Sixteen furniture ensembles were tested having various parameters with respect to isolation and sound absorption. Results. The values of D S ranged from 0t o2 2dB. Regarding normal workstations, the isolation correlated strongly with D S while the weighted absorption coefficient α w and screen height did not. The measurement uncertainty of D S was0.9 dB being sufficient to discriminate twoensembles if their D S values differ more than this value. However, typical values for open workstations and partially open workstations seemed to be low. They cannot always be discriminated. Practical implications. As imple method wasd eveloped to determine the acoustic performance of furniture ensembles. Test laboratories are encouraged to apply this method to acquire more experience in this regard.

Acoustic design in open offices aims most often to the reduction of distractions and improvement of speech privacy. This can be reached by high room absorption, high and absorptive screens and appropriate masking sound level. The aim of this study was to show, how these individual design components can affect room acoustics, using new room acoustical descriptors. The effect of different acoustical remedies on room acoustics were studied in four independent offices. The implemented room acoustical changes were: increased room absorption, sound-absorbing screens, curtains between workers and increased masking sound level. Radius of distraction, r D , spatial attenuation rate of A-weighted sound pressure level of speech, DL 2 , and A-weighted speech level at 4 m from speaker, L p,S,4m , were determined before and after the room acoustical change. In addition, some other room parameters were investigated. Parameters DL 2 , r D and L p,S,4m reacted logically to the room acoustical changes. These three simple and robust single-number parameters are recommended to characterize the acoustic conditions of open offices. They are already included into a Finnish acoustic guideline.

Acoustic and thermal performance greatly affect in lecture halls as, acoustic, architecture and thermal treatments play an important role to enhance acoustic and thermal performance in space and therefore increasing sentiment of acoustic and thermal comfort in space. This research get down to the role of acoustic, architecture and thermal treatments to enhance acoustic and thermal performance of internal acoustic and thermal environment for main lecture hall of Tanta engineering whereas, the hall suffers great acoustic and thermal problems, all because of several reasons, most important it, sky light of ceiling, integration work done between acoustic and thermal treatments to achieve best acoustic and thermal performance and using ODEON software to evaluate suggested treatments acoustically and selection the best then evaluate it by DESIGN BUILDER software to calculate the range of energy consumption reduce in hall after these suggested treatments. It helped to enhance acoustic and thermal performance level in hall and increasing sentiment of acoustic and thermal comfort in hall. RT value of lecture hall reduce from RT=3.5 Hz to RT=0.95 Hz and the range of energy consumption reduce in hall after these treatments 70%.

Acoustic and thermal performance greatly affect in lecture halls as, acoustic, architecture and thermal treatments play an important role to enhance acoustic and thermal performance in space and therefore increasing sentiment of acoustic and thermal comfort in space. This research get down to the role of acoustic, architecture and thermal treatments to enhance acoustic and thermal performance of internal acoustic and thermal environment for main lecture hall of Tanta engineering whereas, the hall suffers great acoustic and thermal problems, all because of several reasons, most important it, sky light of ceiling, integration work done between acoustic and thermal treatments to achieve best acoustic and thermal performance and using ODEON software to evaluate suggested treatments acoustically and selection the best then evaluate it by DESIGN BUILDER software to calculate the range of energy consumption reduce in hall after these suggested treatments. It helped to enhance acoustic and thermal performance level in hall and increasing sentiment of acoustic and thermal comfort in hall. RT value of lecture hall reduce from RT=3.5 Hz to RT=0.95 Hz and the range of energy consumption reduce in hall after these treatments 70%.

Purpose This study investigated the classification accuracy of a concentrated English narrative dynamic assessment (DA) for identifying language impairment (LI). Method Forty-two Spanish–English bilingual kindergarten to third-grade children (10 LI and 32 with no LI) were administered two 25-min DA test–teach–test sessions. Pre- and posttest narrative retells were scored in real time. Using a structured intervention approach, examiners taught children missing story grammar elements and subordination. A posttest was administered using a parallel story. Results Four classification predictors were analyzed: posttest scores, gain scores, modifiability ratings, and teaching duration. Discriminant function analysis indicated that an overall modifiability rating was the best classifier, with 100% sensitivity and 88% specificity after 1 DA session and 100% sensitivity and specificity after 2 sessions. Any 2 combinations of posttest scores, modifiability ratings, and teaching duration for ju...

For lecture halls, the intelligibility of speech is the most important aspect. To achieve a relatively uniform distribution of sound among the listeners, a number of parameters must be taken into account. One method to speed up the design process of a lecture hall is to model the sound propagation in that room using computer acoustic software. In this paper, the authors have chosen a lecture hall from the Naval Academy and made numerous simulations to discover what are the week points regarding the acoustics of this room. The acoustical parameters obtained from simulations are compared with the desired ones and a few remarks for the improvement of the room are made.

Telephone conversation is ubiquitous within the office setting. Overhearing a telephone conversation-whereby only one of the two speakers is heard-is subjectively more annoying and objectively more distracting than overhearing a full conversation. The present study sought to determine whether this "halfalogue" effect is attributable to unexpected offsets and onsets within the background speech (acoustic unexpectedness) or to the tendency to predict the unheard part of the conversation (semantic [un]predictability), and whether these effects can be shielded against through top-down cognitive control. In Experiment 1, participants performed an office-related task in quiet or in the presence of halfalogue and dialogue background speech. Irrelevant speech was either meaningful or meaningless speech. The halfalogue effect was only present for the meaningful speech condition. Experiment 2 addressed whether higher task-engagement could shield against the halfalogue effect by mani...

The design of cost-efficient workspaces has become significantly important in the 21st century. Organizations aim to reduce rental costs and fit their employees into smaller spaces because of financial issues. As a result of the idea of companies to reduce land costs, open-plan offices where employees occupy less square meters with the elimination of interior walls are introduced into workplace design. Open-plan offices provide integrated workspaces that enable employees to interact and communicate with their colleagues. On the other hand, these integrated spaces result in the invasion of acoustical and visual privacy in open-plan offices that even outweighs the main positive effect of these offices as interaction. The possible effect of visual and acoustical privacy on employee interactions is still an uncertain issue in open-plan offices, thus, this study aims to fill this gap through a computational approach. In order to investigate the research questions, the study uses mixed methods research techniques through space syntax methodology. The study starts with qualitative data collection in order to define employee interaction networks through observation and mapped survey techniques. The second step of the study is quantitative data collection that combines visibility graph analysis and acoustical analysis. Depthmap software is used as an instrument in order to obtain generic visibility analysis. Then, targeted visibility analysis is performed following the development of a new script for Depthmap software. The last step of the quantitative data collection is an acoustical analysis conducted by ODEON room acoustics simulation and measuring software. Following qualitative and quantitative data collection, outputs of these analyses and mapped surveys are compared in order to understand how targeted visibility, generic visibility, and room acoustics affect employee interactions in open-plan offices.

A major health issue in open-plan offices has emerged: noise; occupants of these new work spaces report sources of intelligible speech as the most irritating type of noise. Fluctuations in speech levels prevent people from completing some highly demanding tasks, thus inducing annoyance and fatigue. Many studies have attempted to identify a sound metric reflecting this Irrelevant Speech Effect. Hongisto et al. ( ) have shown that the Speech Transmission Effect can be used to assess disturbance due to a neighbour in the office. More recently, Schlittmeier et al. (2008) suggested that fluctuation strength could be used to assess how fluctuations in ambient noise levels affect task performance. This paper presents a new metric based on measurement of short-term temporal modulation of sound levels. Results indicate that this metric is as efficient as the Speech Transmission Index (STI) or FS, while being more suitable for in situ experiments and easier for health and safety practitioners to use.

As a result of having low partitions between workstations, most of the open plan offices have poor speech privacy conditions. Utilization of high-cost acoustic treatment usually is necessary to improve this condition. In order to increase the speech privacy without increasing the installation cost, the acoustical condition can be optimized by rearranging the office layout through computer simulation. Referring to the guidelines of measurement setup and calculation as derived in ISO 3328-3:2012, ray tracing simulation has been conducted to find this optimum condition. Results on this paper show that the acoustical condition can be improved through layout, workstation, or screen partition modification.

Before creating a new activity based design in retrofit buildings the existing acoustic environment is being carefully measured. Not only the acoustic conditions of the existing building are being measured on the field of room acoustics and building acoustics (according to ISO 3382 for room acoustics, ISO 3382-3:2012 for room acoustics in open plan offices and NEN 5077 for sound insulation), as a very important input for defining the acoustic environment the actual behaviour of people is being measured as well. During a representative week of working hours, the sound levels are being monitored at different locations in the open plan office. To gather information about the character of the sound, sound fragments are as well being recorded based on a trigger level. Defining the acoustic environment of (semi-)open plan offices based on measurements provides a good starting point for redesigning a diversity of office environments. Often the new design leads to activity based office plan...

mobile devices, perceived speech signal degrades significantly in the presence of background noise as it reaches directly at the listener"s ears. There is a need to improve the intelligibility and quality of the received speech signal in noisy environments by incorporating speech enhancement algorithms. This paper focuses on speech enhancement method including auditory masking properties of the human ear to improve the intelligibility and quality of the speech signal in the presence of near-end noise. Implemented by dynamically enhancing the speech signal when the near-end noise dominates. Intelligibility and quality of enhanced speech signal are measured using SII and PESQ. Experimental results show improvement in the intelligibility and quality of the enhanced speech signal with the proposed approach over the unprocessed speech signal. This particular approach is far more efficient in overcoming the degradation of speech signals in noisy environments. KeywordsMasking, Near-en...

In mobile devices, perceived speech signal deteriorates significantly in the presence of near-end noise as the signal arrives directly at the listener's ears in a noisy environment. There is an inherent need to increase the clarity and quality of the received speech signal in noisier environment. It is accomplished by incorporating speech enhancement algorithms at the receiver end. The objective is to improve the intelligibility and quality of the speech signal by dynamically enhancing the speech signal when the nearend noise dominates. This paper proposes a speech enhancement approaches by inculcating the threshold of hearing and auditory masking properties of the human ear. Incorporating the masking properties, the speech samples that are audible can be obtained. In low SNR environments, selective audible samples can be enhanced to improve the clarity of the signal rather than enhancing every loud sample. Intelligibility and quality of the enhanced speech signal are measured using Speech Intelligibility Index and Perceptual Evaluation of Speech Quality. Experimental results connote the intelligibility and quality improvement of the speech signal with the proposed method over the unprocessed far-end speech signal. This approach is efficient in overcoming the deterioration of speech signals in a noisy environment.

In mobile phones, perceived speech signal deteriorates significantly in the presence of background noise as noise reaches directly at the listener's ears. There is an inherent need to increase the intelligibility of the received speech signal in noisy environments by incorporating speech enhancement algorithm at the receiverend. This paper focus on the enhancement of selective speech samples for the intelligibility improvement, when the near-end noise dominates. Audible speech samples are selected by consideringthreshold of hearing and auditory masking properties of the human ear. Intelligibility of enhanced speech signalis measured using Speech Intelligibility Index. Experimental results show the intelligibility improvement of the speech signal in lower SNR with the proposed approach to the unprocessed far-end speech signal. This approach is efficient in overcoming the degradation of speech signals in very noisy environments.

In mobile phones, perceived quality of speech signal deteriorates significantly in the presence of background noise since near-end/surrounding noise also arrives at the near-end listener's ears. The quality of the received signal varies widely depending upon signal strength and unavoidable background noise in the user environment. There is a need to improve the quality of received speech signal in noisy conditions by developing the speech enhancement algorithms. This paper focuses on the impact of the various background noises on signal degradation and mechanisms to mitigate the noise impact for improved speech signal perception. Gain adjustment process with simple time domain and frequency domain approach using psychoacoustic has been adapted to improve the quality and intelligibility of the speech signal in the noisy environments by automatically enhancing the speech signals when the noise dominates. Time domain approach is less complex and frequency domain using psychoacoustic is more efficient in overcoming the degradation of speech signals in presence of near-end or background noise.

Research indicates that children and young adults are at risk for noise-induced hearing loss and can benefi t from hearing conservation instruction. The purpose of this study was to examine participant learning about hearing conservation topics, including background information (e.g., anatomy and physiology) and hearing conservationspecifi c content (e.g., hearing loss prevention), as presented through a lecture vs. a computer-based format and assessed by a 20-point post-instruction exam. The results indicated greater learning of background content for lecture instruction, but no difference between instructional modes for hearing conservation-specifi c material. These data are discussed in terms of implications for secondary education.

In the new international standard ISO 3382-3 the measurement procedure for open-plan offices is described and a number of new room acoustical parameters for the objective evaluation are defined. Among the new parameters are the privacy distance and the distraction distance, both derived from the STI (speech transmission index). With room acoustic simulation software these measurements can be simulated, thus providing a tool for the acoustical design of open-plan offices. The paper presents an example office with a range of alternative acoustical solutions that include different amount of absorption, screens of different height, and different levels of background noise. Also the influence of dynamic background noise from people talking can be taken into account, leading to a significantly reduced privacy distance. The computer simulations provide a background for evaluating the efficiency of various acoustical measures in open-plan office design.

This paper reports the acoustic issues of open plan office environments. According to a detailed research based on the scientific literature of the most suitable acoustic descriptors recommended for the open plan offices analysis, the main typological-functional configurations of these environments have been analyzed in order to identify six spatial typologies. The variation of acoustic parameters of these typologies has been evaluated by using a sound pyramid tracing software. The analysis procedure was calibrated in a case study of an office environment, where a measurement campaign was carried out. Results point out that the acoustic improvement of open plan offices can usually be achieved by introducing a sound absorbing false ceiling and dividing panels between working positions, but there are different issues depending on spatial geometries of the office. Better results are referred to office typologies characterized by reduced height and equal plan dimensions.

Contemporary architectonic design mostly relies on the software tools which enable the engineers to analyze multiple factors affecting a space, and to timely detect and correct certain errors in designing, resulting from attempting to satisfy certain aspects of a space at the expense of others. Those tools which apart from architecture itself also consider other fields of science, depending on the function of these areas are important; thus in the lecture halls designing process, adequate software for analysis is used. In addition to a number of acoustic parameters characterizing the acoustic response of a room, in terms of design, one of the most important factors affecting the acoustics of the indoor areas is reverberation time, which is characterized by the architectonic parameters: room volume (dimensions), shape (form) and materialization (finish material). In this paper, for the purposes of acoustic analysis of the A amphitheater, the parametric values obtained in two ways, by experimental measuring and by software-Autodesk Ecotect and Autodesk Revit Architecture are compared. The software is increasingly used in contemporary architectonic software because of the option to analyze acoustics of indoor space, so there is a need to analyzed the values provided by the software and compare them with actually measured reverberation time.

One of the most used intelligibility's parameters is the Speech Transmission Index: the techniques for determining it employs artificial speaker and listener. Inside cars, where signal to noise ratio is particularly low, the value of STI is mainly influenced by this ratio and determining the sound power of real speakers is the only way for piloting correctly the artificial mouth. We have implemented a technique that is based on throat-activated microphone and it is able to find the level of real speaker's voice inside noisy spaces in the effective conditions. Especially, we have studied the speech inside cars and we have discovered how the value defined by typical configuration may be extremely different from real one and, in this way, we have been able to produce more reliable excitation signals. Using this "raised" signal we have tested one car and we have tried to find a good correlation between drivers' impression and objective values. 1. The parameter that is able to consider all these effects is the Speech Transmission Index: the methods for Bozzoli and Farina Speech Transmission Index inside cars and its correlation with drivers' impression

One of the most used intelligibility's parameters is the Speech Transmission Index: the techniques for determining it employs artificial speaker and listener. Inside cars, where signal to noise ratio is particularly low, the value of STI is mainly influenced by this ratio and determining the sound power of real speakers is the only way for piloting correctly the artificial mouth. We have implemented a technique that is based on throat-activated microphone and it is able to find the level of real speaker's voice inside noisy spaces in the effective conditions. Especially, we have studied the speech inside cars and we have discovered how the value defined by typical configuration may be extremely different from real one and, in this way, we have been able to produce more reliable excitation signals. Using this "raised" signal we have tested one car and we have tried to find a good correlation between drivers' impression and objective values. 1. The parameter that is able to consider all these effects is the Speech Transmission Index: the methods for Bozzoli and Farina Speech Transmission Index inside cars and its correlation with drivers' impression

The concept of near end listening enhancement has recently been proposed for improving the speech intelligibility of telecommunication equipment in the presence of ambient noise. Near end listening enhancement is a signal processing framework that acts on the received signal from the far end speaker to reduce the listening effort of the near end speaker. Since it is often not acceptable/possible to increase the emitted loudspeaker power, this paper investigates the opportunities of listening enhancement under the constraint that the processed loudspeaker signal power is strictly equal to the power of the received signal. We will compare two reasonable processing strategies: a previous one that aims at the amplification of speech at noisy frequencies and a new one which cuts down the speech power at noisy frequencies. The results show that a considerable improvement of speech intelligibility can be achieved by the second approach which can be understood by a simple model of human hearing.

In the new international standard ISO 3382-3 the measurement procedure for open plan offices is described and a number of new room acoustical parameters for the objective evaluation are defined. Among the new parameters are the privacy distance and the distraction distance, both derived from the STI (speech transmission index) as a function of distance from the sound source. The final evaluation is a balanced compromise between a number of parameters that depend on the amount of sound absorption, the application of screens between work stations and the level of background noise. With room acoustic simulation software these measurements can be simulated, thus providing a tool for the acoustical design of open plan offices. The paper presents an example office with a range of alternative acoustical solutions that include different amount of absorption, screens of different height, and different levels of background noise. Also the influence of dynamic background noise from people talking can be taken into account, leading to a shorter privacy distance. This provides a background for the discussion of the efficiency of various acoustical measures in open plan office design.

Current office designs frequently arrange several workstations in one open room. While this office design may reduce costs, background speech in this environment may hinder an operator's ability to do one of the most common office tasks - reading. Background irrelevant speech combined with relevant linguistic processing may contribute to higher levels of mental workload. Prior cognitive research indicates that background speech degrades performance in reading comprehension tasks. This experiment examined whether background conversation affects perceptions of difficulty of another kind of linguistic processing task, a computer-based proof-reading task. There were three auditory background conditions: quiet, continuous speech (a conversation between two persons) and discontinuous speech (with one or the other person in the conversation, simulating a phone conversation). Results indicated that discontinuous speech is perceived as significantly more difficult than quiet. It is suggested that the greater disturbance by discontinuous speech is due to the combination of the distraction of speech and its unpredictable onset and offset. Implications for office work settings are discussed.

This study modeled the open-plan office environment by introducing background speech (a common workplace noise) at moderate decibel levels and measuring performance on a computer editing task. Also assessed was whether focussed attention moderates the effects of background speech on task performance. Editing accuracy was significantly higher under quiet compared to continuous background speech conditions. Results also showed that participants scoring higher on focused attention using the Tellegen Absorption Scale (Tellegen & Atkinsson, 1974) were more accurate detectors of certain types of errors and edited more lines of text than low absorbers. Implications for open-plan office design, selection of personnel, technology deployment in non-optimal environments, and the importance of focused attention are discussed.

This paper analyzes two Auditoria at the Faculty of Engineering, Helwan University, Cairo, Egypt. Based on the clarity of speech for educational facilities. This research was carried out on adapting the field survey to determine the architectural and acoustic measurements, followed by a digital simulation using CATT for both rooms. Sustainable treatments were provided to improve the sound environment of the learning process and were again tested using CATT. Analysis and simulation indicate that both rooms suffer from poor acoustics due to the surrounding area and the finishing materials selection. One possible solution to this problem is to use a new sustainable absorbent to maximize uptake, reducing excessive reverberation time to acceptable values, increasing early reflections and eliminating shadow areas that improve speech clarity for all receivers.

Saturation is  basically explained or defined as the coverage of the inner ear and the auditory system of a person.

The sensory neurons in the inner ear and the auditory nerve that respond to sound are physiological machines that run on chemical supplies.
Consequently, when they run low on supplies, or are running at maximum capacity, they may fail to respond to sound as vigorously as usual.

Acoustic comfort in open-plan offices is a relatively recent research topic and some practices have not yet been consolidated. The goal in these spaces is to achieve good speech privacy at every workstation, reaching a high value of spatial decay of the sound pressure level. In case of refurbishment, a proper measurement of intelligibility criteria is needed, for example, in order to properly calibrate a numerical model or to plan acoustic treatments. This work compares different measurement techniques to evaluate the spatial distribution of intelligibility criteria. In situ measurements were done in an open-plan office used as a case study. Both omnidirectional and directional sound sources with different sound power levels were used, according, respectively, to ISO 3382-3:2012 and ITU-T P.51:1996. Furthermore, compensation algorithms were used in impulse response measurements in presence of Heating, Ventilation and Air Conditioning noise. The study shows, in a preliminary way, how different techniques and equipment can influence intelligibility criteria used in the open-plan office characterization. Results show that the indirect method of measuring Speech Transmission Index could not be used when the background level is high as the case study while the direct method returns good results.

The present paper deals with the study of the acoustic properties of the Lecture Hall belonging to the Faculty of Building Services in Cluj-Napoca; the hall is dedicated to both teaching activities and used as a national and international conference venue; complex measures to ameliorate the acoustic features of the hall are also envisaged. After performing the acoustic measurements and processing the data found, it was found out that the reverberation time was not situated in the standard range limits and that several measures to improve the hall acoustics were required. The paper presents several proposals to improve the acoustic properties of the hall and a costs analysis of these solutions. The acoustic properties of the hall were determined in accordance with the Romanian standards that are in full agreement with the European norms.

This paper compares the effect of send-side music and environmental noise as background noise in a telephone communication. The study focuses on the quality experienced by the end user in the context of NB, WB and SWB mobile speech communication. The subjective test procedure defined in ITU-T Rec. P.835 is followed in this study. The results show that music as background noise in telephone conversation deteriorates the overall quality experienced by the end user. Moreover, the impact of music background noise on the quality is similar to that of the environmental noise. Furthermore it is shown that the music background noise seems to be slightly less intrusive than the environmental noise, especially when it comes to the lower SNR.

Purpose: Fatigue related to speech processing is an understudied area that may have significant negative effects, especially in children who spend the majority of their school days listening to classroom instruction. Method: This study examined the feasibility of using auditory P300 responses and behavioral indices (lapses of attention and self-report) to measure fatigue resulting from sustained listening demands in 27 children (M = 9.28 years). Results: Consistent with predictions, increased lapses of attention, longer reaction times, reduced P300 amplitudes to infrequent target stimuli, and self-report of greater fatigue were observed after the completion of a series of demanding listening tasks compared with the baseline values. The event-related potential responses correlated with the behavioral measures of performance. Conclusion: These findings suggest that neural and behavioral responses indexing attention and processing resources show promise as effective markers of fatigue in children.

Many business offices around the world are organized as open plan offices. Therefore, studies about the acoustic comfort of the people who work in them have become increasingly important. The focus of this work is the acoustic evaluation of an open plan office combining several architectural characteristics and levels of ambient noise. This evaluation was performed through a computational model calibrated from a real office. The rate of spatial decay of sound pressure levels per distance doubling (DL2) and the speech transmission index (STI) were simulated for the acoustic evaluation of the office, allowing for the determination of the radius of distraction (rD). These parameters were simulated for 6 situations using different floor and ceiling covering materials and inserting or withdrawing screens between workstations. In addition, STI and rD were simulated under two conditions of ambient noise. The results indicated that the DL2 and rD are adequate acoustic parameters for the acoustic evaluation and improvement of an open plan office. The DL2 was strongly influenced by the presence or absence of screens between workstations and by the ceiling covering material. The rD was more sensitive to changes in ambient noise.

In a room when a sound source is switched on and it operates at a steady level, the intensity of the sound field increases (the room-as it were -is being filled with sound) until the energy absorption rate equals the energy input rate. At that point equilibrium would exist and the sound field would be steady.