This thesis investigates how developments in audio for digital television can be utilised to improve the experience of hearing impaired people when watching television. The work has had significant impact on international digital TV broadcast standards; it led to the formation of the UK Clean Audio Forum whose recommendations based on the research have been included in ETSI international standards for digital television, adopted into ITU standards for IPTV and also into EBU and NorDig digital television receiver specifications. In this thesis listening tests are implemented to assess the impact of various processes with a phantom centre channel and with a centre loudspeaker. The impact of non-speech channel attenuation and dynamic range control on speech clarity, sound quality and enjoyment of audio-visual media are investigated for both hearing impaired and non-hearing impaired people. For the first time the impact of acoustical crosstalk in two channel stereo reproduction on intelligibility of speech is quantified using both subjective intelligibility assessments and acoustic measurement techniques with intelligibility benefits of 5.9% found by utilising a centre loudspeaker instead of a phantom centre. A novel implementation of principal component analysis as a pre- broadcast production tool for labelling AV media compatible with a clean audio mix is identified, and two research implementations of accessible audio are documented including an object based implementation of clean audio for live broadcast that has been developed and publicly demonstrated.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:605105 |
| Date | January 2013 |
| Creators | Shirley, B. G. |
| Publisher | University of Salford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://usir.salford.ac.uk/31007/ |
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