Perception of dialect variation in noise: intelligibility and classification

Area of Science:

• Psycholinguistics
• Speech Perception
• Acoustic Phonetics

Background:

• Regional dialect variation is a significant aspect of spoken language.
• The impact of dialect on speech intelligibility and perception in noisy conditions remains under-explored.

Purpose of the Study:

• To investigate how dialect variation influences speech intelligibility in noise.
• To examine the effect of noise on the ability to classify talker dialects.
• To understand listener adaptation to dialect differences under varying noise levels.

Main Methods:

• Four experiments were conducted to assess speech intelligibility and dialect classification.
• Participants listened to talkers with different regional dialects under controlled signal-to-noise ratios (SNRs).
• Listener dialect was analyzed for its interaction with talker dialect and intelligibility.

Main Results:

• Dialect-specific intelligibility differences were more significant at lower SNRs (higher noise) and less pronounced at higher SNRs (lower noise).
• General American talkers were consistently more intelligible than Mid-Atlantic talkers across noise levels.
• Dialect classification accuracy was poor, even with moderate noise, suggesting listeners adapt to acoustic signals.

Conclusions:

• Listeners can neutralize some cross-dialect intelligibility differences at moderate noise levels through adaptation.
• At higher noise levels, adaptation is insufficient, leading to noticeable intelligibility differences regardless of listener dialect.
• Explicit dialect identification is not a prerequisite for intelligibility gains in moderate noise.