Thus, peripheral hearing loss partially contributed to impaired speech in noise perception in older adults.
van Laarhoven, T., Keetels, M., Schakel, L. & Vroomen J. Audio-visual speech in noise perception in dyslexia.
In summary, we revealed an age-related increase of activity in speech motor regions that compensated for performance and dedifferentiated phoneme representations during speech in noise perception.
Thus, stronger activity in speech motor areas (that is, left POp and premotor cortex) was associated with better performance under noise masking in older listeners, consistent with an aging-related compensatory upregulation of frontal regions during speech in noise perception.
Therefore, a reduction in peripheral hearing acuity partly contributed to impaired performance for older adults in the current study, although it alone cannot adequately account for speech in noise perception deficits3,25.
Our findings also suggest that phoneme dedifferentiation may be a neural correlate for difficulty with speech in noise perception, and the binding of bottom-up sensory processing with top-down articulatory predictions substantially impacts speech recognition performance in the elderly.
Regardless of age, the greater phoneme specificity observed in frontal articulatory regions than in auditory and sensorimotor interface regions appears to be a neural marker of top-down sensorimotor mapping during speech in noise perception.
The hypothesis for this study was that different sound characters in the noise not fully described by the equivalent noise level, are of importance for annoyance and noise perception.
Furthermore, the sensorimotor integration function, reflected in greater phoneme specificity in frontal motor than auditory regions, was shifted towards lower task demands in older adults compared with young adults, suggesting that older adults relied to a greater extent on speech motor compensation during speech in noise perception relative to younger counterparts.
Dr. Whitton is currently collaborating to make tablet-based diagnostics and training applications for patients who are living with presbycusis, a large group of individuals (26 million in the US alone) who present with impaired signal in noise perception even after treatment with hearing aids.
