Updated: June 15, 2004

Investigators:

Harry Levitt, Ph.D.
Linda Kozma-Spytek, M.A.
Matthew H. Bakke, Ph.D.

Purpose of this study:

To develop and evaluate a practical technique for predicting the amount of electromagnetic interference for a given hearing aid wireless phone combination, and to determine a user's ability to understand speech in such a condition.

Project Description:

A method for measuring and categorizing the electromagnetic field produced by a wireless telephone and the hearing aid's immunity to an electromagnetic field has been developed (ANSI, 2001). An analysis of the data used in establishing this standard (some of which was gathered by the RERC-HE and RERC-Telecommunications Access) indicate that it should be possible to predict how well a person with a hearing loss will be able to understand speech for different combinations of hearing aids and wireless telephones as specified by these categories.

This project is concerned with developing and evaluating experimentally a practical technique for predicting the amount of electromagnetic interference that is audible to the hearing aid user for a given hearing aid-wireless telephone combination and then to determine the user's ability to understand speech in the presence of this interference. A predictive technique of this type will be of great value to consumers, hearing aid dispensers, service providers, researchers and others concerned with the effect of electromagnetic interference on telephone communication by people.

Progress to-date:

Data have been obtained on interference produced by a newly introduced technology (the IDEN system developed by Motorola). The repetition rate of this technology is much lower than that of the other systems used in wireless telephony, resulting in audio interference with a correspondingly lower fundamental frequency.

Recent publications or presentations:

Levitt, H. In-the-Ear Measurements of Hearing Aid Interference, RERC-HE, ICDR Summit on Interference to Hearing Technologies by Digital Wireless Telephones, Washington, DC, September, 2003.

Levitt, H. Hearing Aids in the Age of Personal Wireless Communication, VA Conference on Rehabilitative Audiology, Portland, OR, September, 2003.

For more information, contact: Harry Levitt, Ph.D.