Abstract
Elevated hearing thresholds in hearing impaired adults are usually compensated by providing amplification through a hearing aid. In spite of restoring hearing sensitivity, difficulties with understanding speech in noisy environments often remain. One main reason is that sensorineural hearing loss not only causes loss of audibility but also other deficits, including peripheral distortion but also central temporal processing deficits. To investigate the neural consequences of hearing impairment in the brain underlying speech-in-noise difficulties, we compared EEG responses to natural speech of 14 hearing impaired adults with those of 14 age-matched normal-hearing adults. We measured neural envelope tracking to sentences and a story masked by different levels of a stationary noise or competing talker. Despite their sensorineural hearing loss, hearing impaired adults showed higher neural envelope tracking of the target than the competing talker, similar to their normal-hearing peers. Furthermore, hearing impairment was related to an additional increase in neural envelope tracking of the target talker, suggesting that hearing impaired adults may have an enhanced sensitivity to envelope modulations or require a larger differential tracking of target versus competing talker to neurally segregate speech from noise. Lastly, both normal-hearing and hearing impaired participants showed an increase in neural envelope tracking with increasing speech understanding. Hence, our results open avenues towards new clinical applications, such as neuro-steered prostheses as well as objective and automatic measurements of speech understanding performance.
Highlights
Adults with hearing impairment can neurally segregate speech from background noise
Hearing loss is related to enhanced neural envelope tracking of the target talker
Neural envelope tracking has potential to objectively measure speech understanding
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Email adresses:
Lien Decruy: liendecruy{at}gmail.com
Jonas Vanthornhout: jonas.vanthornhout{at}kuleuven.be
Tom Francart: tom.francart{at}med.kuleuven.be
Contact emailaddress of corresponding author is changed. No changes to manuscript since February 2020.
Abbreviations
- AIC
- Akaike’s Information Criterion
- ASSR
- Auditory steady-state response
- CAEP
- Cortical auditory evoked potentials
- CT
- competing talker
- dB HL
- decibel Hearing level
- dB SNR
- decibel Signal-to-noise ratio
- df
- degrees of freedom
- HI
- hearing impairment
- EEG
- electroencephalography
- LFM
- Linear Fixed-effect Model
- LMM
- Linear Mixed-effect Model
- MEG
- magnetoencephalography
- NAL-RP
- National Acoustics Laboratory-Revised Profound algorithm
- NH
- normal-hearing
- PTA
- pure tone average
- RST
- Reading Span Test
- SE
- standard error
- SNR
- signal-to-noise ratio
- SRT
- speech reception threshold
- SU
- speech understanding
- SWN
- speech-weighted noise1