Comparison of fluctuating maskers for speech recognition tests

Area of Science:

• Auditory perception
• Speech processing
• Psychoacoustics

Background:

• Understanding speech in noisy environments is crucial for hearing aid development.
• Masker characteristics influence speech recognition performance.
• Temporal fine structure and gaps play roles in auditory scene analysis.

Purpose of the Study:

• To determine how temporal gaps, temporal fine structure, and masker comprehensibility affect speech masking.
• To compare the effectiveness of different masker types in speech recognition experiments.

Main Methods:

• Evaluated seven masker types, including fluctuating noise (ICRA-5), international speech test signal (ISTS), and competing talkers (Dutch and Swedish).
• Tested both normal-hearing and hearing-impaired participants.
• Analyzed psychometric function slopes and masker effects.

Main Results:

• Normal-hearing listeners benefited from temporal gaps and fine structure in fluctuating maskers.
• Comprehensible competing talkers reduced speech recognition performance.
• The ISTS masker introduced significant informational masking.
• Stationary maskers produced the steepest psychometric slopes, followed by modulated noises and then competing talkers.
• Hearing-impaired listeners showed similar trends, though individual results varied.

Conclusions:

• Non-modulated maskers are suitable when measurement time is critical.
• Fluctuating noises are recommended for assessing masking release due to temporal gaps.
• Foreign-language competing talkers are advised for investigating the perception of temporal fine structure.