International Audio Laboratories Erlangen

Evaluation of the Speech Resynthesis Capabilities of the VoicePrivacy Challenge Baseline B1

Ünal Ege Gaznepoğlu and Nils Peters

Presented as selected papers from the 2023 ISCA SPSC Symposium on Security and Privacy in Speech Communication, August 19, 2023. The 2023 ISCA SPSC Symposium is a satellite event of Interspeech 2023.

Abstract

Speaker anonymization systems continue to improve their ability to obfuscate the original speaker characteristics in a speech signal, but often create processing artifacts and unnatural sounding voices as a tradeoff. Many of those systems stem from the VoicePrivacy Challenge Baseline B1, using a neural vocoder to synthesize speech from an F0, x-vectors and bottleneck features-based speech representation. Inspired by this, we investigate the reproduction capabilities of the aforementioned baseline, to assess how successful the shared methodology is in synthesizing human-like speech. We use four objective metrics to measure speech quality, waveform similarity, and F0 similarity. Our findings indicate that both the speech representation and the vocoder introduces artifacts, causing an unnatural perception. A MUSHRA-like listening test on 18 subjects corroborate our findings, motivating further research on the analysis and synthesis components of the VoicePrivacy Challenge Baseline B1.

Listening test sound stimuli

8455-210777-0034.wav

p229_016_mic2.wav

p226_080_mic2.wav

p232_015_mic2.wav

5142-36377-0023.wav

p287_015_mic2.wav

1995-1837-0004.wav

8463-294828-0006.wav

6829-68771-0013.wav

p269_015_mic2.wav

7729-102255-0031.wav

8230-279154-0024.wav

p225_024_mic2.wav

260-123286-0018.wav

Paper (click to enlarge)

@techreport{2023_gaznepoglu_evaluation_vpc,
author = {Ünal Ege Gaznepoğlu, Nils Peters},
institution = {3rd ISCA Symp. on Security and Privacy in Speech Communication (SPSC)},
title = {Evaluation of the Speech Resynthesis Capabilities of the VoicePrivacy Challenge Baseline B1},
keywords = {},
year = {2023}}