DocumentCode :
3425870
Title :
Temporal masking for bit-rate reduction in audio codec based on Frequency Domain Linear Prediction
Author :
Ganapathy, Sriram ; Motlicek, Petr ; Hermansky, Hynek ; Garudadri, Harinath
Author_Institution :
IDIAP Res. Inst., Martigny
fYear :
2008
fDate :
March 31 2008-April 4 2008
Firstpage :
4781
Lastpage :
4784
Abstract :
Audio coding based on frequency domain linear prediction (FDLP) uses auto-regressive model to approximate Hilbert envelopes in frequency sub-bands for relatively long temporal segments. Although the basic technique achieves good quality of the reconstructed signal, there is a need for improving the coding efficiency. In this paper, we present a novel method for the application of temporal masking to reduce the bit-rate in a FDLP based codec. Temporal masking refers to the hearing phenomenon, where the exposure to a sound reduces response to following sounds for a certain period of time (up to 200 ms). In the proposed version of the codec, a first order forward masking model of the human ear is implemented and informal listening experiments using additive white noise are performed to obtain the exact noise masking thresholds. Subsequently, this masking model is employed in encoding the sub- band FDLP carrier signal. Application of the temporal masking in the FDLP codec results in a bit-rate reduction of about 10% without degrading the quality. Performance evaluation is done with perceptual evaluation of audio quality (PEAQ) scores and with subjective listening tests.
Keywords :
Hilbert spaces; audio coding; autoregressive processes; codecs; ear; hearing; linear predictive coding; white noise; Hilbert envelopes; PEAQ scores; additive white noise; audio codecs; audio coding; autoregressive model; bit-rate reduction; forward masking; frequency domain linear prediction; hearing; human ear; informal listening; noise masking; temporal masking; Acoustic noise; Additive white noise; Audio coding; Auditory system; Codecs; Ear; Frequency domain analysis; Humans; Masking threshold; Predictive models; Audio coding; Frequency Domain Linear Prediciton (FDLP); Psychoacoustic modelling; Temporal masking;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Acoustics, Speech and Signal Processing, 2008. ICASSP 2008. IEEE International Conference on
Conference_Location :
Las Vegas, NV
ISSN :
1520-6149
Print_ISBN :
978-1-4244-1483-3
Electronic_ISBN :
1520-6149
Type :
conf
DOI :
10.1109/ICASSP.2008.4518726
Filename :
4518726
Link To Document :
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