Stress versus coarticulation: toward an integrated approach to explicit speech segmentation

Area of Science:

• Psycholinguistics
• Auditory Perception
• Speech Processing

Background:

• Word stress is considered a significant cue for segmenting continuous speech.
• Previous research suggests stress patterns influence speech perception and comprehension.
• The interplay between acoustic cues like stress and coarticulation in speech segmentation requires further investigation.

Purpose of the Study:

• To investigate the effectiveness of word stress as a speech segmentation cue.
• To examine the influence of coarticulation on stress-based segmentation.
• To determine how background noise affects the role of stress in speech segmentation.

Main Methods:

• Conducted five cross-modal fragment priming experiments.
• Utilized auditory primes with varying stress patterns and visual targets.
• Manipulated coarticulatory cues (uncoarticulated vs. coarticulated primes) and background noise levels.

Main Results:

• Auditory prime stress patterns did not affect lexical decision latencies to visual targets in clear speech.
• Priming was facilitated by uncoarticulated primes but not by coarticulated ones.
• In noisy conditions, stress-initial primes significantly enhanced pruning compared to non-initial-stress primes, irrespective of coarticulation.

Conclusions:

• Coarticulation plays a crucial role in speech segmentation within clear speech environments.
• Word stress becomes a more dominant segmentation cue in impoverished listening conditions (e.g., background noise).
• An integrated, signal-contingent approach is necessary for understanding speech segmentation processes.