Research Projects

The Global Burden of Disease Study 2019 reveals that every person in five has hearing loss, which can be congenital, aging, or exposure to loud noise. Undiagnosed hearing loss can negatively impact quality of life, hinder speech development in children, cause loneliness, isolation, depression, dementia, and cognitive decline in the elderly. Therefore, timely hearing screening tests and appropriate assistive hearing devices are necessary. Comprehensive hearing screening tests are needed to assess the nature and severity of hearing loss. Common methods for auditory function assessment include air conduction and bone conduction pure-tone thresholds, speech recognition thresholds, and suprathreshold speech recognition. However, these methods are standardized for English-speaking adults and require active participation and feedback from listeners, which may be difficult for children and infants. Otoacoustic emissions (OAEs) and auditory evoked potentials (AEPs) are other methods for auditory function assessment. AEP-based hearing threshold estimation is suitable for infants, children, and those who lack reliable response to stimuli. However, measurement of AEP requires proper electrode placement and there is a need to address changes in recorded signals due to differences in electrode placements. Perceived loudness is a subjective quantity correlated to physical sound intensity and frequency, and it varies in complex ways that cannot be accounted for by the listener's threshold level. Therefore, there is a need to estimate loudness growth, hearing thresholds, and discomfort levels from physiological signals like AEP or auditory brainstem response (ABR) for both normal and hearing-impaired listeners.