Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505959
Title: Beyond 'basic audio quality' : characterizing the perceptual effects introduced by low bit rate spatial audio codecs
Author: Marins, Paulo
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 2009
Availability of Full Text:
Access from EThOS:
Access from Institution:
Abstract:
The main aim of this thesis was to characterize the perceptual effects introduced by low bit rate spatial audio codecs. The existing methodologies used to evaluate spatial audio codecs were reviewed and the most important studies conducted to assess the perceived quality of spatial audio coding systems were compared. It was found that spatial audio codecs have been evaluated according to ITU-R standards BS.1116 and BS.1534. These tests evaluate the performance of audio codecs using one perceptual attribute - basic audio quality (BAQ). This approach, although effective in terms of the assessment of the overall performance of codecs, does not quantify the contribution of typical codec distortions to the perceived BAQ of the codecs or allow for the identification of independent perceptual attributes that describe the artefacts introduced by spatial audio coding systems. A series of experiments was carried out aiming to characterize the perceptual effects introduced by low bit rate spatial audio codecs. Two initial studies were conducted with the intention of investigating the contribution of selected attributes to the BAQ of low bit rate spatial codecs. Furthermore, another two experiments were performed in order to identify the perceptually salient dimensions or the independent perceptual attributes related to the artefacts introduced by low bit rate spatial audio coding systems. It was found that impairments related to timbral features of the sound are the ones that affect the most the perceived basic audio quality of the codecs. Additionally, two perceptually salient dimensions were identified and labelled as timbral and spatial. Moreover, four independent perceptual attributes (coding and high frequency noise, spatial image clarity, scene width and tone colour) were uncovered providing a description of the perceptual effects introduced by low bit rate spatial audio codecs.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.505959  DOI: Not available
Share: