Quality Assessment of Two Fullband Audio Codecs Supporting Real-Time Communication

Maruschke, Michael; Jokisch, Oliver; Meszaros, Martin; Trojahn, Franziska; Hoffmann, M.

doi:10.1007/978-3-319-43958-7_69

Cited by 8 publications

(7 citation statements)

References 2 publications

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“…For data transmission, compression is heavily used within modern (mobile/remote) systems. Compression allows reducing the transmission bandwidth while retaining the speech intelligibility (ITU-T, 1996; ITU-T, 2014; Maruschke et al, 2016). Several codecs have been developed to meet various applications with different quality requirements (Siegert et al, 2016a).…”

Section: Audio Codecsmentioning

confidence: 99%

Case Report: Women, Be Aware that Your Vocal Charisma can Dwindle in Remote Meetings

Siegert

Niebuhr

2021

Front. Commun.

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Remote meetings via Zoom, Skype, or Teams limit the range and richness of nonverbal communication signals. Not just because of the typically sub-optimal light, posture, and gaze conditions, but also because of the reduced speaker visibility. Consequently, the speaker’s voice becomes immensely important, especially when it comes to being persuasive and conveying charismatic attributes. However, to offer a reliable service and limit the transmission bandwidth, remote meeting tools heavily rely on signal compression. It has never been analyzed how this compression affects a speaker’s persuasive and overall charismatic impact. Our study addresses this gap for the audio signal. A perception experiment was carried out in which listeners rated short stimulus utterances with systematically varied compression rates and techniques. The scalar ratings concerned a set of charismatic speaker attributes. Results show that the applied audio compression significantly influences the assessment of a speaker’s charismatic impact and that, particularly female speakers seem to be systematically disadvantaged by audio compression rates and techniques. Their charismatic impact decreases over a larger range of different codecs; and this decrease is additionally also more strongly pronounced than for male speakers. We discuss these findings with respect to two possible explanations. The first explanation is signal-based: audio compression codecs could be generally optimized for male speech and, thus, degrade female speech more (particularly in terms of charisma-associated features). Alternatively, the explanation is in the ears of the listeners who are less forgiving of signal degradation when rating female speakers’ charisma.

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Section: Audio Codecsmentioning

confidence: 99%

Case Report: Women, Be Aware that Your Vocal Charisma can Dwindle in Remote Meetings

Siegert

Niebuhr

2021

Front. Commun.

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“…The main purpose of applying speech compression for mobile communication is to reduce the bandwidth for transmission, the transmission delay as well as the required system memory and storage (Maruschke et al, 2016;Siegert et al, 2016). Several codecs have been developed to meet various applications with different quality requirements, aiming to retain the speech intelligibility (ITU-T, 1996(ITU-T, , 2014Maruschke et al, 2016). To be in line with the previous investigations by the Siegert and Niebuhr (2021a,b), and Niebuhr and Siegert (2022), the same four codecs were utilized here.…”

Section: Utilized Audio Codecsmentioning

confidence: 99%

A digital “flat affect”? Popular speech compression codecs and their effects on emotional prosody

Niebuhr

Siegert²

2023

Front. Commun.

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IntroductionCalls via video apps, mobile phones and similar digital channels are a rapidly growing form of speech communication. Such calls are not only— and perhaps less and less— about exchanging content, but about creating, maintaining, and expanding social and business networks. In the phonetic code of speech, these social and emotional signals are considerably shaped by (or encoded in) prosody. However, according to previous studies, it is precisely this prosody that is significantly distorted by modern compression codecs. As a result, the identification of emotions becomes blurred and can even be lost to the extent that opposing emotions like joy and anger or disgust and sadness are no longer differentiated on the recipients' side. The present study searches for the acoustic origins of these perceptual findings.MethodA set of 108 sentences from the Berlin Database of Emotional Speech served as speech material in our study. The sentences were realized by professional actors (2m, 2f) with seven different emotions (neutral, fear, disgust, joy, boredom, anger, sadness) and acoustically analyzed in the original uncompressed (WAV) version and as well as in strongly compressed versions based on the four popular codecs AMR-WB, MP3, OPUS, and SPEEX. The analysis included 6 tonal (i.e. f0-related) and 7 non-tonal prosodic parameters (e.g., formants as well as acoustic-energy and spectral-slope estimates).ResultsResults show significant, codec-specific distortion effects on all 13 prosodic parameter measurements compared to the WAV reference condition. Means values of automatic measurement can, across sentences, deviate by up to 20% from the values of the WAV reference condition. Moreover, the effects go in opposite directions for tonal and non-tonal parameters. While tonal parameters are distorted by speech compression such that the acoustic differences between emotions are increased, compressing non-tonal parameters make the acoustic-prosodic profiles of emotions more similar to each other, particularly under MP3 and SPEEX compression.DiscussionThe term “flat affect” comes from the medical field and describes a person's inability to express or display emotions. So, does strong compression of emotional speech create a “digital flat affect”? The answer to this question is a conditional “yes”. We provided clear evidence for a “digital flat affect”. However, it seems less strongly pronounced in the present acoustic measurements than in previous perception data, and it manifests itself more strongly in non-tonal than in tonal parameters. We discuss the practical implications of our findings for the everyday use of digital communication devices and critically reflect on the generalizability of our findings, also with respect to their origins in the codecs' inner mechanics.

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“…Additionally, audio evaluation by the authors in [15] assess the performance of codecs Opus and Enhanced Voice Services (EVS), which were tested through vocal, instrumental, and mixed music signals using POLQA [14]. The effect of lower bitrates (16.4 kbit/s and 20 kbit/s respectively for EVS and OPUS), indicate high degradation.…”

Section: A Evaluation Of Quality Of Experience (Qoe)mentioning

confidence: 99%

“…The authors of [14] also focus on the audio and speech quality assessment of the Opus codec within the real-time communication mode. As in the work by the authors of [15], digital signals are assessed through POLQA, and additionally, through the non-standardized Audio Quality Analyzer (AQuA) from Sevana company. The authors state that the prediction of the instrumental measures should closely correspond to quality scores from a human listening test, considered a subjective test.…”

Section: A Evaluation Of Quality Of Experience (Qoe)mentioning

confidence: 99%

“…QoE of RTC has been previously analyzed based on the network and protocols [1], latency [3], and audio [10], [11]. However, there is discrepancy as to which methods of audio evaluation are superior [1], [15]. The ITU-R BS.1534-3 MUlti Stimulus test with Hidden Reference and Anchor (MUSHRA) has been designed as a subjective measurement of intermediate quality level of audio systems and has been used to evaluate technology such as headsets, speech codecs for telecommunication, and audio codecs [19].…”

Section: A Purposementioning

confidence: 99%

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A Perceptual Evaluation of Music Real-Time Communication Applications

et al. 2023

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Music Real-time Communication applications (M-RTC) enable music making (musiking) for musicians simultaneously across geographic distance. When used for musiking, M-RTC such as Zoom and JackTrip, require satisfactorily received acoustical perception of the transmitted music to the end user; however, degradation of audio can be a deterrent to using M-RTC for the musician. Specific to the audio quality of M-RTC, we evaluate the quality of the audio, or the Quality of Experience (QoE), of five network music conferencing applications through quantitative perceptual analysis to determine if the results are commensurate with data analysis. The ITU-R BS.1534-3 MUlti Stimulus test with Hidden Reference and Anchor (MUSHRA) analysis is used to evaluate the perceived audio quality of the transmitted audio files in our study and to detect differences between the transmitted audio files and the hidden reference file. A comparison of the signal-to-noise ratio (SNR) and total harmonic distortion (THD) analysis to the MUSHRA analysis shows that the objective metrics may indicate that SNR and THD are factors in perceptual evaluation and may play a role in perceived audio quality; however, the SNR and THD scores do not directly correspond to the MUSHRA analysis and do not adequately represent the preferences of the individual listener. Since the benefits of improved M-RTC continue to be face-to-face communication, face-to-face musiking, reduction in travel costs, and depletion of travel time, further testing with statistical analysis of a larger sample size can provide the additional statistical power necessary to make conclusions to that end.INDEX TERMS MUSHRA, music real-time communications (M-RTC), networked music, perceived audio quality, perceptual evaluation, quality of experience (QoE), signal to noise ratio (SNR), telematic, total harmonic distortion (THD), web RTC. I. INTRODUCTIONMusic Real-time Communication applications (M-RTC) enable music making (musiking) for all levels of musicians simultaneously across geographic distance. Real-time Communications (RTC) [1] allows voice and video communication of individuals and groups over the Internet. Network Music Performance software (NMP), as described by the authors in [2], are software applications designed specifically for real-time communications which allow musiking between participants in different physical locations via the Internet [2]. However, M-RTC can include any conferencing application that is capable of transmitting audio over the Internet. M-RTC has seen an increase in demand due to social distancing and itsThe associate editor coordinating the review of this manuscript and approving it for publication was Guangjie Han .

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Quality Assessment of Two Fullband Audio Codecs Supporting Real-Time Communication

Cited by 8 publications

References 2 publications

Case Report: Women, Be Aware that Your Vocal Charisma can Dwindle in Remote Meetings

Case Report: Women, Be Aware that Your Vocal Charisma can Dwindle in Remote Meetings

A digital “flat affect”? Popular speech compression codecs and their effects on emotional prosody

A Perceptual Evaluation of Music Real-Time Communication Applications

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