Scientific Article

Effects of fundamental frequency and vocal tract resonance on speech recognition in noise by non-native listeners

¹ Department of Music, Hunan University of Science and Technology Xiangtan Hunan PR China
² Program of Communication Sciences and Disorders, University of Wisconsin-Milwaukee Milwaukee WI USA
³ Department of Otolaryngology & Communication Sciences, Medical College of Wisconsin-Milwaukee Milwaukee WI USA
⁴ Department of Hearing, Speech and Language Sciences, Ohio University Athens OH USA

^* Corresponding author: jyang888@uwm.edu

Received: 5 April 2025
Accepted: 10 June 2025

Abstract

The present study examined the influence of changes in speakers’ fundamental frequency (f_o) and vocal tract resonance (VTR) on speech recognition in different types of noise by non-native listeners. The goal was to identify whether the f_o-VTR relationship has a similar effect on non-native listeners as it does on native listeners. Twenty-six adults who were native Mandarin speakers learning English as a second language were presented with English Hearing-in-Noise Test (HINT) sentences in four voice conditions with the original male speaker's f_o doubled and/or VTR scaled up by a factor of 1.2: (1) low f_o low VTR (L_foL_VTR, the original recordings); (2) low f_o high VTR (L_foH_VTR); (3) high f_o high VTR (H_foH_VTR), and (4) high f_o low VTR (H_foL_VTR). The stimuli were presented in speech-shaped noise (SSN) and four-talker babble (FTB) at signal-to-noise ratios of −3, 0, +3 dB. The results showed that the non-native listeners performed more poorly with f_o-VTR mismatched voices than with f_o-VTR matched voices and the negative influence of mismatched voice features was mainly manifested in the H_foL_VTR condition. Compared to SSN, FTB had a greater adverse impact on the non-native listeners’ recognition accuracy. Further, the performance difference between matched and mismatched conditions showed distinct patterns across SSN and FTB.