Factors Affecting the Accessibility of Voice Telephony for People with Hearing Loss: Audio Encoding, Network Impairments, Video and Environmental Noise

This paper describes four studies with a total of 114 individuals with hearing loss and 12 hearing controls that investigate the impact of audio quality parameters on voice telecommunications. These studies were first informed by a survey of 439 individuals with hearing loss on their voice telecommunications experiences. While voice telephony was very important, with high usage of wireless mobile phones, respondents reported relatively low satisfaction with their hearing devices’ performance for telephone listening, noting that improved telephone audio quality was a significant need. The studies cover three categories of audio quality parameters: (1) narrowband (NB) versus wideband (WB) audio; (2) encoding audio at varying bit rates, from typical rates used in today's mobile networks to the highest quality supported by these audio codecs; and (3) absence of packet loss to worst-case packet loss in both mobile and VoIP networks. Additionally, NB versus WB audio was tested in auditory-only and audiovisual presentation modes and in quiet and noisy environments. With WB audio in a quiet environment, individuals with hearing loss exhibited better speech recognition, expended less perceived mental effort, and rated speech quality higher than with NB audio. WB audio provided a greater benefit when listening alone than when the visual channel also was available. The noisy environment significantly degraded performance for both presentation modes, but particularly for listening alone. Bit rate affected speech recognition for NB audio, and speech quality ratings for both NB and WB audio. Packet loss affected all of speech recognition, mental effort, and speech quality ratings. WB versus NB audio also affected hearing individuals, especially under packet loss. These results are discussed in terms of the practical steps they suggest for the implementation of telecommunications systems and related technical standards and policy considerations to improve the accessibility of voice telephony for people with hearing loss.

Wrapped Into Sound: Development of the Immersive Audio Quality Inventory (IAQI)

Although virtual reality, video entertainment, and computer games are dependent on the three-dimensional reproduction of sound (including front, rear, and height channels), it remains unclear whether 3D-audio formats actually intensify the emotional listening experience. There is currently no valid inventory for the objective measurement of immersive listening experiences resulting from audio playback formats with decreasing degrees of immersion (from mono to stereo, 5.1, and 3D). The development of the Immersive Audio Quality Inventory (IAQI) could close this gap. An initial item list (N = 25) was derived from studies in virtual reality and spatial audio, supplemented by researcher-developed items and items extracted from historical descriptions. Psychometric evaluation was conducted by an online study (N = 222 valid cases). Based on controlled headphone playback, participants listened to four songs/pieces, each in the three formats of mono, stereo, and binaural 3D audio. The latent construct “immersive listening experience” was determined by probabilistic test theory (item response theory, IRT) and by means of the many-facet Rasch measurement (MFRM). As a result, the specified MFRM model showed good model fit (62.69% of explained variance). The final one-dimensional inventory consists of 10 items and will be made available in English and German.

Evaluation of digital watermarking on subjective speech quality

New methods of securing the distribution of audio content have been widely deployed in the last twenty years. Their impact on perceptive quality has, however, only been seldomly the subject of recent extensive research. We review digital speech watermarking state of the art and provide subjective testing of watermarked speech samples. Latest speech watermarking techniques are listed, with their specifics and potential for further development. Their current and possible applications are evaluated. Open-source software designed to embed watermarking patterns in audio files is used to produce a set of samples that satisfies the requirements of modern speech-quality subjective assessments. The patchwork algorithm that is coded in the application is mainly considered in this analysis. Different watermark robustness levels are used, which allow determining the threshold of detection to human listeners. The subjective listening tests are conducted following ITU-T P.800 Recommendation, which precisely defines the conditions and requirements for subjective testing. Further analysis tries to determine the effects of noise and various disturbances on watermarked speech’s perceived quality. A threshold of intelligibility is estimated to allow further openings on speech compression techniques with watermarking. The impact of language or social background is evaluated through an additional experiment involving two groups of listeners. Results show significant robustness of the watermarking implementation, retaining both a reasonable net subjective audio quality and security attributes, despite mild levels of distortion and noise. Extended experiments with Chinese listeners open the door to formulate a hypothesis on perception variations with geographical and social backgrounds.

A-189 Survey Findings of Challenges with Teleneuropsychological Assessment and Advice in Mitigating these Challenges

Objective Teleneuropsychology (TeleNP) has experienced tremendous uptake during the coronavirus pandemic, and there is a need to document the challenges and practical advice for conducting remote cognitive assessments. Method 87 respondents (licensed neuropsychologists = 56; others [e.g., trainees] = 31) conducting TeleNP evaluations with adult populations in the United States completed an online survey which was distributed via social media and list-servs in winter 2020–2021. Respondents were asked about their TeleNP experiences, including issues encountered and solutions to TeleNP challenges. Frequency analyses were conducted to examine the proportion of respondents endorsing specific TeleNP challenges. TeleNP advice was thematically coded to identify the most common suggestions to overcome/navigate these challenges. Results The most frequently reported TeleNP challenges included: poor internet connectivity (examinee’s home: 82.8%; an unknown source 58.6%); environmental distractions in the examinee’s location (78.2%); poor audio quality (55.2%); examinee’s unfamiliarity with the videoconferencing technology (52.9%); inability to easily conduct visuoconstructional tasks (52.9%) or adapt tests/find TeleNP norms (47.1%); and examinees’ limited access to technology (57.5%) or complete lack of access (35.6%). The most common responses to mitigate these challenges included: providing detailed instructions about the TeleNP visit and examinee expectations in advance; having a clear back-up or assistive plan (e.g., telephone call); and using TeleNP sparingly (e.g., for interview only). Conclusion These survey results reflect widely-encountered challenges with remote cognitive assessment and identify priority targets for increasing the feasibility and reliability of TeleNP. Findings can be incorporated into discussion about formalized TeleNP competencies.

Best Practice versus Reality

COVID-19 was repeatedly labelled ‘unprecedented’. In unprecedented times, we rethink conventional wisdoms. This short article explores oral history, an important element of the Then & Now student-led research project explored in this Special Issue, with such rethinking in mind. Then & Now’s alumni interviews had to be conducted remotely but remote oral history interviews are not universally popular. The Oral History Society (OHS) is hesitant and suggested postponing interviews, reflecting best practice concerns about rapport-building, audio quality and archiving, data protection and security, and community building. For groups like the Disability Visibility Project (DVP) and oral historians like Sarah Dziedzic, remote interviewing is the only viable method and ideals of best practice are too rigid. For oral history to uncover the experiences of those disregarded by conventional histories, access to it and its employment as a research tool should be as universal as possible. This article examines and questions best practice guidelines in light of the pandemic and the experiences of the DVP and historians such as Dziedzic. It draws on personal experience of interviewing and from the Then & Now project. This article argues that oral history, an inherently fieldwork-based activity, needs to take remote interviewing as seriously as face-to-face interviewing to become more widely accessible and sufficiently flexible to adapt to conditions in the field.