Change search
ReferencesLink to record
Permanent link

Direct link
Memory of AMR coded speech distorted by packet loss
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
University of Gävle.
Show others and affiliations
2014 (Swedish)Conference paper, Presentation (Refereed)
Abstract [en]

Previous studies have shown that free recall of spoken word lists is impaired if the speech is presented in background noise, even if the signal-to-noise ratio is kept at a level allowing full word identification. The objective of this study was to examine recall rates for word lists presented in noise and word lists coded by an AMR (Adaptive Multi Rate) telephone codec distorted by packet loss. Twenty subjects performed a word recall test. Word lists consisting of ten words were played to the subjects. The subjects repeated each word immediately after it had been played, to ensure that the words were heard correctly. After the complete list had been played the subjects wrote down all words remembered. In this way, both word identification and recall rates were measured. Three distorted conditions were compared with an undistorted control condition using a within-subject design: speech spectrum weighted noise at 4 dB SNR, and AMR coded speech with two levels of packet loss, one mild and one severe. The results confirmed the disruptive effect of noise on free recall of words, while no significant impairment was found for the AMR distortions. The noise and the AMR coding with mild packet loss gave approximately the same impairment of word identification. The AMR coding with severe packet loss gave a larger impairment of word identification, even though the word recall rate was unaffected. This result suggests that packet loss in AMR coded speech causes distortions which disrupt recall of words less than noise at levels resulting in the same change of word identification rates. Since impairment of word identification rates did not correlate with impairment of word recall rates models for quality prediction of speech reproductions should not be based on identification rates alone.

Place, publisher, year, edition, pages
Research subject
Engineering Acoustics; Operation and Maintenance
URN: urn:nbn:se:ltu:diva-32099Local ID: 67897be8-33d3-44a4-9ad0-0650ef550319OAI: diva2:1005333
Forum Acusticum : 07/09/2014 - 14/09/2014
Godkänd; 2014; 20141210 (arny)Available from: 2016-09-30 Created: 2016-09-30Bibliographically approved

Open Access in DiVA

fulltext(183 kB)2 downloads
File information
File name FULLTEXT01.pdfFile size 183 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Nykänen, ArneLindegren, DavidOdelius, Johan
By organisation
Operation, Maintenance and Acoustics

Search outside of DiVA

GoogleGoogle Scholar
Total: 2 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 1 hits
ReferencesLink to record
Permanent link

Direct link