The Threshold of Perceptual Significance for TV Soundtracks

Robert J. Acheson; Trevor Agus
DAFx-2023 - Copenhagen
Hearing loss affects 1.5 billion people world-wide [1], affecting many aspects of life, including the ability to hear the television. Simply increasing the volume may restore audibility of the quietest elements, but at a cost of making other elements undesirably loud. Therefore, at the very least, dynamic range compression could also be useful, fitted to an individual’s frequency-dependent hearing loss. However, it is not clear whether the audibility of the quietest parts of TV audio needs to be preserved. This experiment aims to measure which elements of the audio are important by presenting normal-hearing listeners with binary masked versions of TV audio presented at 60 dB(A), muting audio below a given sensation level. It was hypothesised that spectro-temporal regions with the most power density would dominate perception, such that the less active regions may not be missed. To find this threshold of perceptual significance, a two-alternative forced choice signal detection experiment was designed in which excerpts from BBC television shows were binary masked and presented to the participants, with the task to identify which clips sounded more processed. The results suggest that discarding audio below 10 phons would rarely be noticed by most listeners.