Brain meeting: Emma Holmes

Brain meeting

People often face the challenge of understanding speech when other sounds are present ("speech-in-noise perception"). Intriguingly, speech-in-noise perception varies substantially among people, and is particularly difficult for people with hearing loss. In this talk, I will demonstrate that some of these difficulties are attributable to impaired cognitive processes, over and above established peripheral mechanisms.

Even people with ‘normal’ hearing vary widely in their ability to understand speech-in-noise, and I will introduce new tests of central auditory grouping that predict the ability to understand speech-in-noise. These tests explain variance in speech-in-noise perception that is unaccounted for by hearing thresholds. I will discuss our ongoing functional MRI work that establishes the cortical correlates of these processes, which underpin shared difficulty with speech-in-noise perception and with basic auditory grouping.

Second, I will show that peripheral hearing loss disrupts a neural signature of auditory selective attention, and hearing aids do not restore this neural signature. Thus, difficulty attending to sounds might help to explain why people with hearing loss find it particularly difficult to understand speech when background noise is present, further compounding difficulties that arise from impairments at the ear.

Finally, I will discuss how prior knowledge can be utilised to improve speech intelligibility in noisy places. For example, people can better understand speech when it is spoken by someone familiar (e.g., a friend or partner) than unfamiliar—and voices are more intelligible even after relatively brief training. Consistent with this intelligibility benefit, speech spoken by familiar people evokes multivariate patterns of neural activity that are more robust to competing sounds than speech spoken by unfamiliar people.

There will be coffee, tea and cake in the conservatory directly after the talk.