Spatial separation enhances speech intelligibility but increases listening effort with session-dependent variability...

Area of Science:

• Auditory neuroscience
• Speech perception research
• Psychoacoustics

Background:

• Cognitive load in listening is understood through speech intelligibility and pupillometry.
• Reliability of pupil dilation metrics in spatial release from masking (SRM) is not well-established.

Purpose of the Study:

• To investigate the impact of spatial sound source separation on listening effort and speech intelligibility.
• To assess the reliability of peak pupil dilation (PPD) as a measure of listening effort in SRM conditions.

Main Methods:

• Speech intelligibility and listening effort (PPD) were measured simultaneously.
• Participants were tested in co-located and spatially-separated conditions across various SNRs.

Main Results:

• Spatial separation enhanced speech intelligibility but did not reduce listening effort.
• Listening effort increased with more challenging SNRs.
• Test-retest reliability was higher for intelligibility than for PPD, especially at easier SNRs.

Conclusions:

• Measuring listening effort using PPD in SRM paradigms presents challenges.
• Combining SRM with PPD yields weak test session reliability, potentially impacting statistical power.
• Future studies require larger, diverse samples to generalize findings on listening effort and spatial hearing.