The aim of this project is to enable accurate acquisition of distortion product otoacoustic emission (DPOAE) measurements in relatively high noise environments for use in hearing evaluations and screening. DPOAE measurements have been shown to be an effective and efficient method for screening infant, child, and adult hearing. Environmental noise, however, can adversely affect the ability to successfully obtain DPOAE measurements. We are working to achieve our aim by developing a narrow-band, adaptive active noise reduction system that seamlessly augments existing DPOAE measurement protocols. Our innovation will supplement existing DPOAE measurement systems with both low-cost acoustic hardware and advanced signal processing techniques. By reducing background noise levels in a narrow frequency band near the DPOAE test frequencies, we enable higher signal-to-noise ratio (SNR) DPOAE measurements. The increased SNR results in the ability to obtain DPOAE measurements in relatively high noise environments such as the newborn intensive care unit and nursery, offices of pediatricians, field hospitals, and remote or mobile clinics. Our Phase I results clearly demonstrated our innovation. Results of pilot human subject tests show an increase of approximately 10 dB in the SNR at the DPOAE frequency for measurements in a common clinical noise environment. ? ?
