A COMPUTERIZED DISTORTION-PRODUCT HEARING SCREENER

RECENT RESEARCH HAS ESTABLISHED A NEW CLASS OF AUDITORY RESPONSES TERMED OTOACOUSTIC EMISSIONS THAT CAN BE OBJECTIVELY MEASURED IN THE EAR CANAL OF ALL NORMAL HEARING INDIVIDUALS. THUS, IT IS NOW POSSIBLE TO DEVELOP OBJECTIVE HEARING-SCREENING INSTRUMENTS FOR THE ASSESSMENT OF DYSFUNCTION BASED UPON THE ABSENCE OF EMITTED RESPONSES. ONE TYPE OF EMISSION ELICITED BY THE APPLICATION OF CONTINUOUS PURE TONES IS CALLED A DISTORTION-PRODUCT EMISSION (DPE). DPES CAN PROVIDE A DETAILED OBJECTIVE AUDIOGRAM WITHIN A REASONABLY SHORT TIME PERIOD. MOREOVER, DPES CAN BE MEASURED OVER A RELATIVELY LARGE RANGE OF HEARING LOSS. THIS PROJECT AIMS TO COMPRESS EXISTING LABORATORY INSTRUMENTATION FOR THE COLLECTION OF DPES INTO A MICROCOMPUTER-BASED CLINICAL DEVICE. A PORTABLE, EASY-TO-OPERATE INSTRUMENT WILL ALLOW COLLECTION OF SUFFICIENT NORMATIVE DATA IN A CLINICAL SETTING SO THAT THE DEVICE CAN EVENTUALLY BE REFINED INTO A COMMERCIAL PACKAGE FOR ROUTINE HEARING SCREENING. PHASE I WORK WILL ADAPT CURRENT LABORATORY SOFTWARE TO OPERATE ON A MACINTOSH II MICROCOMPUTER AND REPLACE GENERAL-PURPOSE LABORATORY INSTRUMENTATION WITH ON-BOARD SIGNAL-GENERATION AND SPECTRAL-ANALYSIS FUNCTIONS. SOFTWARE-BASED NOISE-REJECTION SCHEMES WILL BE DEVELOPED TO INCREASE THE MEASURABLE RANGE OF DPES AND TO PERMIT EMISSIONS TO BE COLLECTED EVENTUALLY IN A QUIET CLINICAL SETTING. PHASE II WORK WILL REFINE THE PROTOTYPICAL DEVICE, UPDATE SOFTWARE-USER INTERFACES, AND COLLECT SUBSTANTIAL NORMATIVE DATA FROM BOTH NORMAL HEARING AND HEARING-IMPAIRED INDIVIDUALS.