Hearing in time.
Altogether, the findings of the HEART project are compatible with the idea that the early auditory system represents modulation information (i.e., AM and FM patterns) crucial for accurate reception of communication sounds such as animal vocalizations or speech using two neural codes: i.e., a purely temporal and a rate/place code. These findings are also consistent with the notion that both ageing and cochlear damage alter differentially the sensory encoding of this modulation information. Consistent with human data, animal recordings revealed robust coding of modulation information in the auditory cortex following age-related sensorineural hearing loss but increased susceptibility to signal distortions caused by background noise. In humans, our findings indicated that ageing and cochlear damage are also associated with reduced (central) “processing efficiency”, as modeled by an increase in internal noise in computational models of auditory processing. However, ageing and cochlear damage seem to spare short-term memory and decision-making processes. These initial results should pave the way for the development of novel screening tools assessing suprathreshold auditory capacities and complementing the diagnosis of sensorineural hearing loss in humans.
Main publications from UMR LSP:
Wallaert, N., Moore, B.C.J., Ewert, S., & Lorenzi, C. (2017). Sensorineural hearing loss enhances auditory sensitivity and temporal integration for amplitude modulation. Journal of the Acoustical Society of America, 141, 971-980.
Paraouty, N., & Lorenzi, C. (2017). Using individual differences to assess modulation-processing mechanisms and age effects. Hearing Research, 344, 38-49.
Paraouty, N., Ewert, S., Wallaert, N., & Lorenzi, C. (2016). Interactions between amplitude-modulation and frequency-modulation processing: Effects of age and hearing loss.Journal of the Acoustical Society of America, 140,121-131.Wallaert, N., Moore, B.C.J., & Lorenzi, C. (2016). Comparing the effects of age on amplitude-modulation and frequency-modulation detection. Journal of the Acoustical Society of America, 139, 3088-3096.