An unusual application of a CROS hearing aid

This paper describes the use of the CROS hearing aid principle on cases of congenital atresia. This young girl has had several operations which attempted to create a canal and tympanum, but the canal persisted in closing. A bone vibrator eyeglass hearing aid was fitted but was largely unsuccessful. Having a 50 db air-conduction loss was handicapping to this youngster, but the usual head worn hearing aid could not be fitted because of the lack of any canal, causing feedback. She refused a body type aid. The solution is this case was a CROS behind-the-ear hearing aid. She enjoys about a 25 db useful gain from this fitting.