Signal delivery/real ear measurement system for hearing aid selection and fitting

This report describes a signal delivery/real ear measurement system for application in the hearing aid selection and fitting process. This signal delivery/real ear measurement system provides a means for quantifying a listener's auditory characteristics (e.g., thresholds, loudness discomfort levels) in a manner that is compatible with electroacoustic measures of hearing aid performance. The signal delivery/real ear measurement system consists of a button-type hearing aid receiver coupled to the listener's personal earmold, and a probe tube microphone system to measure the signal level within the occluded ear canal. This signal delivery/real ear measurement system was used to measure detection thresholds and loudness discomfort levels in severe/profoundly hearing-impaired school-age children, with results indicating good test-retest reliability in behavioral responses. The findings presented in this report relate to the intersession electroacoustic variability associated with this instrumentation. In addition, the potential application of this or a similar system for measuring real ear to 2-cc coupler difference values is illustrated and discussed.