Laterality differences in speaker and consonant identification in dichotic listening

Area of Science:

• Auditory Neuroscience
• Psychoacoustics
• Speech Perception

Background:

• Speaker identification is crucial for auditory scene analysis.
• Previous research indicates hemispheric lateralization for various speech sound processing tasks.
• The lateralization of speaker identification, specifically, remains less understood.

Purpose of the Study:

• To investigate the lateralization of speaker identification in right-handed native English speakers.
• To compare the ear advantage for identifying consonants versus speakers in dichotic listening tasks.
• To explore the influence of speaker sex on identification accuracy.

Main Methods:

• Conducted two dichotic listening experiments with right-handed native English speakers.
• Utilized consonant-vowel syllables (/ba/, /da/, /pa/, /ta/) spoken by two male and two female speakers.
• Subjects performed tasks involving identification of consonants or speakers under different stimulus conditions.

Main Results:

• A significant right-ear advantage was observed for consonant identification.
• No significant ear differences were found for speaker identification.
• Speaker judgments were more accurate than consonant judgments.
• Identification accuracy for speakers was higher when speakers were of the same sex compared to different sexes.

Conclusions:

• Neither cerebral hemisphere appears to dominate speaker identification, unlike consonant identification.
• This lack of clear lateralization may be attributed to information loss in ipsilateral auditory pathways.
• Auditory processing for speaker identity may involve more bilateral hemispheric engagement.