Perceptual consequences of native and non-native clear speech

Area of Science:

• Speech Perception
• Acoustic Phonetics
• Second Language Acquisition

Background:

• Native speakers enhance speech acoustics for clarity, improving listener comprehension.
• Research on clear speech primarily focuses on native speakers, leaving non-native speaker capabilities less understood.
• The perceptual benefits of clear speech produced by non-native speakers for native listeners remain unclear.

Purpose of the Study:

• To investigate if non-native English talkers can adopt a clear speaking style.
• To determine if clear speech produced by non-native talkers benefits native listeners' intelligibility.
• To examine acoustic modifications in clear speech across different proficiency levels and their perceptual impact.

Main Methods:

• Native English listeners transcribed plain and clear speech samples.
• Speech samples were produced by three groups: native English speakers, lower-proficiency non-native speakers, and higher-proficiency non-native speakers.
• Acoustic analyses were performed to identify modifications associated with clear speech.

Main Results:

• Both native and non-native talkers modified their speech when prompted to speak clearly.
• The extent of acoustic modifications in clear speech differed between native and non-native talkers.
• Perceptual benefits of clear speech varied based on the talker's language background and proficiency.

Conclusions:

• Non-native speakers are capable of producing clear speech, similar to native speakers.
• Acoustic adjustments in clear speech and its intelligibility benefits are influenced by language proficiency.
• Further research is needed to fully understand the nuances of clear speech production and perception in non-native speakers.