The sub-band cepstrum as a tool for local spectral analysis in forensic voice comparison

Shunichi Ishihara, Frantz Clermont


Abstract
This paper exploits band-limited cepstral coefficients (BLCCs) in forensic voice comparison (FVC), with the primary aim of locating speaker-sensitive spectral regions. BLCCs are sub-band cepstral coefficients (CCs) which are easily obtained by a linear transformation of full-band CCs. The transformation gives the flexibility of selecting any sub-band region without the recurrent cost of spectral analyses. Using multi-band BLCCs obtained by sliding a 600-Hz sub-band every 400 Hz across the full [0-5kHz] range, FVC experiments were attempted using citation recordings of the 5 Japanese vowels from 297 adult-male, native speakers. The FVC results give locations and ranges for the most speaker-sensitive sub-bands, and show that combining 3-4 of these yields comparable FVC performance with full-band CCs. Owing to their ability to easily extract locally-encoded speaker information from full-band CCs, it can be conjectured that BLCCs have a significant role to play in the search for meaningful interpretations of the numerical outcome of forensic analyses.
Anthology ID:
2023.alta-1.5
Volume:
Proceedings of the 21st Annual Workshop of the Australasian Language Technology Association
Month:
November
Year:
2023
Address:
Melbourne, Australia
Editors:
Smaranda Muresan, Vivian Chen, Kennington Casey, Vandyke David, Dethlefs Nina, Inoue Koji, Ekstedt Erik, Ultes Stefan
Venue:
ALTA
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
40–50
Language:
URL:
https://aclanthology.org/2023.alta-1.5
DOI:
Bibkey:
Cite (ACL):
Shunichi Ishihara and Frantz Clermont. 2023. The sub-band cepstrum as a tool for local spectral analysis in forensic voice comparison. In Proceedings of the 21st Annual Workshop of the Australasian Language Technology Association, pages 40–50, Melbourne, Australia. Association for Computational Linguistics.
Cite (Informal):
The sub-band cepstrum as a tool for local spectral analysis in forensic voice comparison (Ishihara & Clermont, ALTA 2023)
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PDF:
https://aclanthology.org/2023.alta-1.5.pdf