Validation of the C63.19 standard: Acoustic measurements and subjective evaluations

Abstract

The ANSI C63.19 measurement and performance standard addresses the electromagnetic compatibility of hearing aids with wireless communication devices. Validation of the measurement procedures and performance criteria comprised a pilot study, objective validation, and subjective validation. Objective validation involved acoustic measurements of 80 combinations of hearing aids and wireless phones. The E-field and H-field immunity levels of each hearing aid and the E-field and H-field emissions of each wireless phone were measured according to the standard. These data were used to theoretically predict the overall input referenced interference level. Across a broad range of hearing aid immunity levels, the measured acoustic interference was accurately predicted from the individual C63.19 measurements. Subjective validation involved the testing of twenty hearing aid wearers with six phone technologies. Hearing aids offering a variety of immunity levels were custom manufactured for the participants and tested according to the C63.19 measurement procedures. While using each wireless phone, participants provided ratings of the speech intelligibility, usability, and annoyance caused by any rf interference. In addition to confirming the existence of compatible hearing aids and phones, the results of this study contributed to the setting of the immunity and emissions criteria for a usable hearing aid wireless phone system.