Individual Differences in the Discrimination of Novel Speech Sounds: Effects of Sex, Temporal Processing, Musical and Cognitive Abilities

John C Thoresen,Felix Schaeffler,Vera Kempe,Patricia J Brooks,Johan J Bolhuis,Neil W Kirk

doi:10.1371/journal.pone.0048623

Abstract

This study examined whether rapid temporal auditory processing, verbal working memory capacity, non-verbal intelligence, executive functioning, musical ability and prior foreign language experience predicted how well native English speakers (N = 120) discriminated Norwegian tonal and vowel contrasts as well as a non-speech analogue of the tonal contrast and a native vowel contrast presented over noise. Results confirmed a male advantage for temporal and tonal processing, and also revealed that temporal processing was associated with both non-verbal intelligence and speech processing. In contrast, effects of musical ability on non-native speech-sound processing and of inhibitory control on vowel discrimination were not mediated by temporal processing. These results suggest that individual differences in non-native speech-sound processing are to some extent determined by temporal auditory processing ability, in which males perform better, but are also determined by a host of other abilities that are deployed flexibly depending on the characteristics of the target sounds.

Highlights

The ability to process rapidly changing temporal information is considered to be fundamental to the process of identifying speech sounds
These sex differences are consistent with studies of non-linguistic temporal processing, which have shown that men tend to outperform women in temporal order judgments [14,15] and temporal discrimination tasks involving the detection of changes in the acoustic properties of stimuli in the range of 200 ms [16]
This study examined to what extent temporal processing ability, and measures of various aspects of cognitive functioning explain individual differences in non-native speech-sound discrimination

Summary

Introduction

The ability to process rapidly changing temporal information is considered to be fundamental to the process of identifying speech sounds. Sex differences have been observed for the perception of a variety of speech sounds that require temporal processing of auditory stimuli with a time course of change in acoustic parameters ranging from under 100 ms for consonantal contrasts to up to about 300 ms for pitch contours and lexical tones These sex differences are consistent with studies of non-linguistic temporal processing, which have shown that men tend to outperform women in temporal order judgments [14,15] and temporal discrimination tasks involving the detection of changes in the acoustic properties of stimuli in the range of 200 ms [16]. While a variety of factors have been invoked to explain this finding, the ability to discriminate rapidly changing features of sound may be one of the mechanisms that puts men at an advantage for imitation, given that peception and production abilities are closely linked [18]

Methods

Results

Conclusion