Sound degradation type differentially affects neural indicators of cognitive workload and speech tracking
Nathan Gagné1, Keelin M Greenlaw1, Emily B J Coffey1
1Department of Psychology, Concordia University, Montréal, Canada; International Laboratory for Brain, Music and Sound Research (BRAMS); The Centre for Research on Brain, Language and Music (CRBLM).
Hearing Research
|May 24, 2025
Summary
Listening in noisy environments is hard. This study shows that noise and degraded sound quality increase cognitive workload and reduce speech encoding, impacting hearing in noise (HIN) perception.
Area of Science:
- Neuroscience
- Auditory Perception
- Cognitive Psychology
Background:
- Hearing-in-noise (HIN) is crucial for daily functioning.
- Effective speech perception in noise relies on the brain enhancing attended speech representations.
- Speech quality degradation (pitch, rhythm) alongside noise adds to listening challenges.
Purpose of the Study:
- To investigate how noise and sound quality affect cognitive workload and neural speech encoding.
- To understand the cognitive demands of everyday difficult listening situations.
Main Methods:
- 20 healthy adults performed a selective listening task with continuous speech.
- Speech was presented as clean, spectrally degraded, or temporally degraded, with and without pink noise.
- Electroencephalography (EEG) recorded neural correlates of cognitive workload (alpha-theta power) and speech encoding accuracy.
Main Results:
- Adding noise significantly increased alpha-theta power (cognitive workload) across all sound conditions.
- Prediction accuracy of speech tracking decreased with noise, indicating poorer speech encoding.
- Temporal degradation further increased EEG power, suggesting a compensatory mechanism.
Conclusions:
- Cognitive workload and speech encoding are distinctly impacted by noise and sound degradation.
- Findings inform interventions for mitigating challenges in everyday difficult listening scenarios.
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