Aging and the effect of background rhythm on selective listening in multiple-source environments

Area of Science:

• Auditory perception
• Psychoacoustics
• Cognitive neuroscience

Background:

• Rhythmic regularities in auditory signals influence selective listening.
• Regular rhythmic structures aid target recognition, while regular backgrounds mask targets more effectively than irregular ones.

Purpose of the Study:

• Investigate the background rhythm effect in auditory selective listening.
• Determine the influence of perceptual similarity between target and background signals.
• Assess the dependence of the background rhythm effect on listener age.

Main Methods:

• Utilized a novel synthetic-vowel identification paradigm.
• Presented young and older listeners with isochronous target sequences interleaved with isochronous or anisochronous background sequences.
• Varied the perceptual similarity between target and background vowel stimuli.

Main Results:

• Listeners were insensitive to background rhythm when target and background were easily distinguishable.
• Regular, perceptually similar backgrounds significantly lowered vowel identification rates compared to irregular backgrounds.
• The background rhythm effect was reduced in older listeners.

Conclusions:

• The background rhythm effect is not due to energetic masking and extends beyond continuous speech stimuli.
• Perceptual similarity is crucial for the background rhythm effect to manifest.
• Sensitivity to background rhythm in multi-source environments may decline with age.