Partial loudness at masker onset indicates temporal effects at supra-threshold levels

Area of Science:

• Auditory perception
• Psychoacoustics
• Signal processing in hearing

Background:

• Auditory masking occurs when a sound signal is made inaudible by another sound (masker).
• Temporal effects in masking describe how the masker's timing influences signal detection.
• Understanding temporal masking is crucial for diagnosing hearing impairments.

Purpose of the Study:

• To investigate temporal effects on auditory signal detection at both threshold and supra-threshold levels.
• To quantify the impact of masker onset delay on signal audibility and perceived loudness.
• To explore the relationship between temporal effects and masker characteristics.

Main Methods:

• Measured the detection threshold of a 4.0-kHz signal with varying onset delays relative to a broadband noise masker.
• Obtained loudness matches between the signal in quiet and the signal with different masker onset delays.
• Defined temporal effect as the level difference required to reach threshold or equal loudness near masker onset versus far from it.

Main Results:

• Temporal effects were observed at both threshold and supra-threshold levels, consistent with a decrease in gain at the masker frequency over time.
• These effects were present in both simultaneous and backward masking conditions.
• Temporal effects were stronger at supra-threshold levels than at threshold, potentially due to transient masker onset effects.

Conclusions:

• Auditory system gain decreases during masker presentation, influencing both detection and loudness perception.
• Transient masker onset effects may contribute to stronger temporal masking at supra-threshold levels.
• Temporal masking effects are significant and extend beyond simultaneous masking scenarios.