Assessment of Speaker Verification Degradation Due to Packet Loss in the Context of Wireless Mobile Devices

This paper considers the adverse effects on speaker verification accuracy caused by two independent forms of speech signal degradation common in mobile communications. The two forms are packet loss in the communications system and ambient noise at the wireless device. The effects of these degradations are assessed independently on a common database of 2000 speakers. Baseline verification performances in terms of equal error rates (EER) show negligible degradation until over 75% of test feature vectors are lost. The EER grows from 3% to just 5% when the loss reaches 88%. In contrast, adding a relatively small amount of noise to the test speech (15dB SNR), with otherwise identical experimental conditions, results in a rise in the EER to 36%. In this latter case, simple speech enhancement leads to a reduction in EER to 21%. The main conclusion of this work is that, for speech-based verification, typical packet loss is likely to incur a negligible degradation in accuracy when compared with the degradation that is associated with typical ambient noise conditions.