Loudnessebu Technical Review – 2010 Q3 1 / 9

Acta Physica Polonica A, 2010

Popularity of television and multitude of commercials during the TV broadcast lead to the analysis of its sound levels. Costs of commercials' time cause producers to make commercials much louder than a regular TV program. The article shows results of commercials and regular program sound level (RMS and FFT) analysis and the difference in sound levels of commercials compared to a regular program. The analysis also shows the difference between public and private TV. The authors of the article suggest a solution to this problem and its effects.

The Journal of the Acoustical Society of America, 2017

During the early years of the International Telecommunication Union (ITU) loudness calculation standard for sound broadcasting [ITU-R (2006), Rec. BS Series, 1770], the need for additional loudness descriptors to evaluate short-form content, such as commercials and live inserts, was identified. This work proposes a loudness control scheme to prevent loudness jumps, which can bother audiences. It employs shortform content audio detection and dynamic range processing methods for the maximum loudness level criteria. Detection is achieved by combining principal component analysis for dimensionality reduction and support vector machines for binary classification. Subsequent processing is based on short-term loudness integrators and Hilbert transformers. The performance was assessed using quality classification metrics and demonstrated through a loudness control example.

The recent loudness measurement recommendations by the ITU and the EBU have gained widespread recognition in the broadcast community. The material it deals with is usually full-range mastered audio content, and its applicability to multitrack material is not yet clear. In the present work we investigate how well the evaluated perception of single track loudness agrees with the measured value as defined by ITU-R BS.1770. We analyze the underlying features that may be the cause for this disparity and propose some parameter alterations that might yield better results for multitrack material with minimal modification to their rating of broadcast content. The best parameter sets are then evaluated by a panel of experts in terms of how well they produce an equal-loudness multitrack mix, and are shown to be significantly more successful.

We present an empirical study of the differences between level-normalization of feature films using the two dominant methods: loudness normalization and speech ("dialog") normalization. The sound of 35 recent 'blockbuster' DVDs were analyzed using both methods. The difference in normalization level was up to 14 dB, on average 5.5 dB. For all films the loudness method provided the lowest normalization level and hence the greatest headroom. Comparison of automatic speech measurement to manual measurement of dialog anchors shows a typical difference of 4.5 dB, with the automatic measurement producing the highest level. Employing the speech-classifier to process rather than measure the films, a listening test suggested that the automatic measure is positively biased because it sometimes fails to distinguish between "normal speech" and speech combined with "action" sounds. Finally, the DialNorm values encoded in the AC-3 streams on DVDs were compared to both the automatically and the manually measured speech levels, and found to match neither one well. 1 L eq = equivalent continuous sound level

2017

This paper describes the development of a loudness-based compressor for live audio streams. The need for this device arose while developing the public sound art project The Overheard, which involves mixing together several live audio streams through a web based mixing interface. In order to preserve a natural sounding dynamic image from the varying sound sources that can be played back under varying conditions, an adaptation of the EBU R128 loudness measurement recommendation, originally developed for levelling non-realtime broadcast material, has been applied. The paper describes the Pure Data implementation and the necessary compromises enforced by the live streaming condition. Lastly observations regarding design challenges, related application areas and future goals are presented.

2013

After decades of deep investigation, the international broadcasting community represented by technical associations and bodies has set precise standards aimed to objectively assess loudness levels of programmes. Although all standards rely on the same algorithm as described in ITU-R BS1770, there are still two possible ways to implement such metering, including Voice Detection and Gating. These two different implementations might, in some cases, provide measurements that significantly differ from each other. Furthermore, whilst the gating feature is uniquely defined in the updated version of BS1770-3, Voice Detection is not currently specified in any standard and its implementation is independently designed by manufacturers. This paper analysis this scenario by comparing the results and robustness provided by three different loudness meters based on Voice Detection. In addition, those values are compared with measurements obtained by using BS1770-3 compliant loudness meters, including tables, comments, and conclusions.

2012 IEEE International Instrumentation and Measurement Technology Conference Proceedings, 2012

This paper presents dual sensor based management system for television viewing at home environment in compliance with BS1770 loudness measurement standard aim of the research was mainly to address the issue of sudden increase in loudness during commercials in between TV programmes. Same approach works for any well. The scope of this research reported here investigate, develop an adaptive loudness control system to create a pleasurable TV viewing environment and to algorithm functionality by simulations. The novel made in paper are the design and the proof of functional efficacy of the loudness management algorithms using the measurements made through the simple instrumentation set in compliance with BS1770 loudness measurement

2009

Previously we introduced the concept of loudness descriptors-key numbers to summarize loudness properties of a broadcast programme or music track. This paper presents the descriptors: Foreground Loudness, which measures the level of foreground sound, and Loudness Range, which quantifies the variation in loudness. Wide loudness-range material may benefit from level-alignment based on foreground loudness rather than overall loudness. We propose to use these descriptors for loudness profiling and alignment, especially when live, raw, and film material is combined with other broadcast programs, thereby minimizing level-jumps and also applying appropriate dynamicsprocessing. Finally, we introduce the "zap test" which can objectively characterize the quality of loudness-balancing schemes, based on statistics of the potential loudness-jumps. A study of loudness-jump tolerance is presented, considering loudness-jumps from a subjective point of view.

2010

It is commonly assumed in broadcasting and film production that audiences determine soundtrack loudness mainly from the speech component. While intelligibility considerations support this idea indirectly, the literature is very short on direct supporting evidence. A listening test was therefore conducted to test this hypothesis. Results suggest that listeners judge loudness from overall levels rather than speech levels. A secondary trend is that listeners tend to compare like with like. Thus listeners will compare speech loudness with other speech content rather than with nonspeech content, and will compare loudness of non-speech content with other non-speech content more than with speech content. A recommendation is made on applying this result for informed program loudness control. 8043 Dash, Bassett & Cabrera Speech & non-speech in program loudness AES 128th Convention, London, UK, 2010 May 22–25 Page 2 of 16

2010

This material was originally intended as part of the article "The Loudness War: Background, Speculation and Recommendations" [1] but was removed for reasons of scope and to keep that article to a manageable length.) In this paper, I briefly review a variety of metrics for quantifying the loudness and dynamic spread of audio recordings. This review was motivated by the need for objective ways of measuring the effects of hypercompression as used in the loudness war.