Advantages of Wideband over Narrowband Channels for Speaker Verification

Wideband communications permit the transmission of an extended frequency range compared to the traditional narrowband. While benefits for automatic speaker recognition can be expected, the extent of the contribution of the additional bandwidth in wideband is still unclear. This work compares the i-vector speaker verification performances employing speech signals of 0-4 kHz, 4-8 kHz, and 0-8 kHz and different sets of cepstral features extracted using linearly-and a mel-spaced filterbanks. Analyses of clean speech and of speech transmitted through commonly employed codecs are conducted separately for male and for female speech. Our evaluation on two different datasets shows the improved speaker verification performance with the extended bandwidth, and also that the linear scale can lead to better results for narrowband signals. The advantages of linear- over mel-scaled features for wideband depend on the speakers’ gender and on the channel distortion. Index Terms: speaker verification, channel degradation