On the Relevance of Bandwidth Extension for Speaker Verification

TL;DR

This study investigates how extending bandwidth from narrow-band to wide-band speech affects speaker verification performance, showing that bandwidth extension can improve accuracy without introducing artifacts.

Contribution

It demonstrates that bandwidth extension enhances speaker verification accuracy and compares different spectral parameterizations across various speech databases.

Findings

Bandwidth extension improves verification accuracy by 1-10%.

No artifacts were introduced by the bandwidth extension algorithm.

Performance gains depend on the spectral parameterization and model order.

Abstract

In this paper, we consider the effect of a bandwidth extension of narrow-band speech signals (0.3-3.4 kHz) to 0.3-8 kHz on speaker verification. Using covariance matrix based verification systems together with detection error trade-off curves, we compare the performance between systems operating on narrow-band, wide-band (0-8 kHz), and bandwidth-extended speech. The experiments were conducted using different short-time spectral parameterizations derived from microphone and ISDN speech databases. The studied bandwidth-extension algorithm did not introduce artifacts that affected the speaker verification task, and we achieved improvements between 1 and 10 percent (depending on the model order) over the verification system designed for narrow-band speech when mel-frequency cepstral coefficients for the short-time spectral parameterization were used.