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Release from speech-on-speech masking in a front-and-back geometry
Neil L Aaronson1, Brad Rakerd, William M Hartmann
1Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
The Journal of the Acoustical Society of America
|March 12, 2009
Summary
Listeners can better understand speech when distracting sounds come from behind, with a slight delay. This release from informational masking peaks at a 2-millisecond delay, improving speech intelligibility.
Area of Science:
- Auditory perception
- Psychoacoustics
- Speech processing
Background:
- Informational masking occurs when similar sound sources interfere with target sound perception.
- Spatial separation of sound sources can reduce masking, but its effectiveness with auditory distracters is complex.
- The Haas effect describes the precedence effect in acoustics, influencing spatial hearing.
Purpose of the Study:
- To investigate the effect of delayed auditory distracters presented from behind on informational masking.
- To quantify the release from masking as a function of delay time.
- To explore the underlying mechanisms, including delay-and-add filtering.
Main Methods:
- Baseline measurement of informational masking with target and distracters in front.
- Introduction of distracters from behind with varying millisecond delays relative to front-presented target.
- Measurement of signal-to-noise ratio (SNR) for release from informational and energetic masking.
Main Results:
- Significant release from informational masking was observed for delays within the Haas region (+/-50 ms).
- Peak release from informational masking (approx. 3.5 dB) occurred at a delay of +/-2 ms.
- Release from energetic masking was observed only for very short delays (+/-0.5 ms).
Conclusions:
- Presenting delayed distracters from behind the listener effectively reduces informational masking.
- The observed release from masking is linked to delay-and-add filtering mechanisms.
- Exploiting temporal and spatial cues can enhance speech intelligibility in noisy environments.
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