Irrelevant speech effect under stationary and adaptive masking conditions

Area of Science:

• Cognitive Psychology
• Auditory Perception
• Human-Computer Interaction

Background:

• The irrelevant speech effect (ISE) demonstrates how background speech impairs cognitive tasks.
• Understanding ISE is crucial for designing environments that minimize auditory distractions.

Purpose of the Study:

• To investigate the impact of different masking conditions on the irrelevant speech effect.
• To compare the effectiveness of stationary versus adaptive noise masking.
• To evaluate acoustic measures for predicting speech-masking effectiveness.

Main Methods:

• Participants performed a serial-recall task under six conditions: silence, speech-only, noise-only, stationary noise (two SNRs), and adaptive noise.
• Performance was measured by error rate over five test blocks across four days.
• Acoustic measures, including Speech Transmission Index (STI) and spectral correlation, were analyzed.

Main Results:

• Serial-recall error rates decreased with practice under silence.
• Adaptive noise masking reduced errors by 9% compared to speech-only and 4.4% compared to low-SNR stationary noise.
• No significant difference in performance between stationary and adaptive maskers when sound levels were matched.

Conclusions:

• Adaptive noise masking offers some benefit over constant speech, but its advantage diminishes when overall sound levels are controlled.
• Frequency-domain acoustic measures may better predict the irrelevant speech effect, particularly with non-stationary maskers.
• Combining acoustic estimators with appropriate weighting could improve prediction accuracy.