Analogue Signals and Digital Data

IFIP International Federation for Information Processing, 2006

Human computer interactions is concerned about ways Users (humans) interact with the computers. Some users can interact with the computer using the traditional methods of a keyboard and mouse as the main input devices and the monitor as the main output device. Due to one reason or another some users cannot be able to interact with machines using a mouse and keyboard device, hence the need for special devices. If we use computer for much more time it is really difficult to sit on the chair, keep hands continually on the keyboard and mouse and keep watching the monitor. To relax our body and interact comfortably with computer need some special device or method so that computer will understand and accept commands with out keyboard or by clicking mouse. Speech recognition systems help users who in one way or the other cannot be able to use the traditional Input and Output (I/O) devices. For about four decades human beings have been dreaming of an "intelligent machine" which can master the natural speech. In its simplest form, this machine should consist of two subsystems, namely automatic speech recognition (ASR) and speech understanding (SU). The goal of ASR is to transcribe natural speech while SU is to understand the meaning of the transcription. Recognizing and understanding a spoken sentence is obviously a knowledge-intensive process, which must take into account all variable information about the speech communication process, from acoustics to semantics and pragmatics.

The instrumented meeting room of the future will help meetings to be more efficient and productive. One of the basic components of the instrumented meeting room is the speech recording device, in most cases a microphone array. The two basic requirements for this microphone array are portability and cost-efficiency, neither of which are provided by current commercially available arrays. This will change in the near future thanks to the availability of new digital MEMS microphones. This dissertation reports on the first successful implementation of a digital MEMS microphone array. This digital MEMS microphone array was designed, implemented, tested and evaluated and successfully compared with an existing analogue microphone array using a state-of-the-art ASR system and adaptation algorithms. The newly built digital MEMS microphone array compares well with the analogue microphone array on the basis of the word error rate achieved in an automated speech recognition system and is highly portable and economical.

Analog and digital signals are used to transmit information, usually through electric signals. In both these technologies, the information, such as any audio or video, is transformed into electric signals. The difference between analog and digital technologies is that in analog technology, information is translated into electric pulses of varying amplitude. In digital technology, translation of information is into binary format (zero or one) where each bit is representative of two distinct amplitudes.

International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2022

Audio Signal Processing is also known as Digital Analog Conversion (DAC). Sound waves are the most common example of longitudinal waves. The speed of sound waves is a particular medium depends on the properties of that temperature and the medium. Sound waves travel through air when the air elements vibrate to produce changes in pressure and density along the direction of the wave's motion. It transforms the Analog Signal into Digital Signals, and then converted Digital Signals is sent to the Devices. Which can be used in Various things., Such as audio signal, RADAR, speed processing, voice recognition, entertainment industry, and to find defected in machines using audio signals or frequencies. The signals pay important role in our day-today communication, perception of environment, and entertainment. A joint time-frequency (TF) approach would be better choice to effectively process this signal. The theory of signal processing and its application to audio was largely developed at Bell Labs in the mid-20 th century. Claude Shannon and Harry Nyquist's early work on communication theory and pulse-code modulation (PCM) laid the foundations for the field.

Popular Music Pedagogies, 2020

As personal computers evolved, their ability to perform the necessary amount of data storage and transfer to allow real-time data acquisition made them an attractive platform for the recording and mixing of sound and music. The earliest attempts to record, edit and play back sound files were stereo systems. Soon, it became possible to record multiple channels of audio at reasonable sample rates and to store, process, mix and play back more complicated sessions, approaching the capabilities of 4-and 8-track analog studio recorders and mixing consoles. The low cost of small computers and the ability to add hardware to the system allowed the development of recording hardware and software that started the move that eventually created the modern digital audio workstation (DAW).

Lung sound (LS) records are first stage of studying breathing diseases and indicate the lung function performance. This paper gives a developing method that records LS using a computerized channel. It discusses the chosen components of this channel that reduce noises. Other purpose of this paper is to provide detailed discussions of the issues concerning digitization and sampling frequency of LS records. The method of recording LS includes two trends: developed hardware and created software. Hardware part ends in analog-digital input of sound card with ADC 16 bits. Software includes displaying LS using created program by Graphical User Interface (GUI) MATLAB. It provides LS record in wave data with 44.1 kHz sampling frequency and converts it to 11.025 kHz sampling frequency for future analysis. The developed computerized recoding channel of lung sound (CRCLS) achieves sensing, capturing, recording, displaying, converting and storing LS records.

Computers and Biomedical Research, 1985

A series of digital computer programs which facilitate the production and control of acoustic stimuli for hearing assessment and research are described. The package, which is available for PDP 11 computers under RT-11, allows sounds to be digitized, adjusted for amplitude and/or dc offset, edited while in digital form, and output to tie or tape. The waveform editor package includes facilities to edit sounds in time-with some sections removed or added with temporal precision of 0.1 msec or better. Two or more sounds may also be combined for stereo or monaural (sound-on-sound) output, or two may be concatenated. Together, the programs permit a wide range of manipulations useful in preparing sound stimuli for use in hearing experiments or in clinical audiometry. o 198s Academic PWS.

Audio processing covers many diverse fields, all involved in presenting sound to human listeners. Three areas are prominent: (1) high fidelity music reproduction, such as in audio compact discs, (2) voice telecommunications, another name for telephone networks, and (3) synthetic speech, where computers generate and recognize human voice patterns. While these applications have different goals and problems, they are linked by a common umpire: the human ear. Digital Signal Processing has produced revolutionary changes in these and other areas of audio processing.

IEEE Micro, 2000

Our low-power analog integrated circuit implements a biologically inspired algorithm for the spectral analysis of sound. The chip features an efficient interface to digital systems; preserving analog processing's low-power, highdensity advantages requires careful attention to interface issues. To send the spectral representation off chip, we generate a sparse coding of the output spectrum, and communicate the code as an asynchronous stream of events. We store parameters for the spectral analysis algorithm as charge on floating nodes, and support the modification of these parameters via Fowler-Nordheim tunneling, under the control of a digital interface. A prototype system we have developed uses this chip as a preprocessor.