Intelligibility of average talkers in typical listening environments

Area of Science:

• Audiology
• Speech Science
• Acoustics

Background:

• Conversational speech intelligibility is crucial for effective communication.
• Understanding factors influencing speech intelligibility in various environments is essential.

Purpose of the Study:

• To investigate intelligibility differences among normal hearing talkers in varied acoustic environments.
• To identify which speech features (vowels, consonants) are most susceptible to degradation.
• To determine if talker intelligibility remains consistent across different listening conditions.

Main Methods:

• Utilized the Speech Pattern Contrast (SPAC) test to quantify intelligibility.
• Evaluated three male and three female talkers in four simulated environments (quiet living room, classroom, two social settings with differing reverberation).
• Assessed overall intelligibility and specific features: vowels, consonant voicing, continuance, and place.

Main Results:

• Significant talker-dependent intelligibility differences were found, even in environments supporting high intelligibility.
• Talker intelligibility was generally consistent across environments, with some susceptibility to reverberation.
• Consonant place was the least intelligible feature, followed by continuance, voicing, and vowels.
• Numerous talker-by-feature interactions indicated variable intelligibility for specific speech sounds.

Conclusions:

• Individual talker characteristics significantly impact speech intelligibility beyond environmental factors.
• Consonant place perception is a key area for intelligibility assessment.
• Selecting an average talker requires evaluating multiple speech contrasts, not just overall intelligibility or acoustic measures.