A Follow-Up Study of the CROS Hearing Aid

Abstract

A recent development in hearing aids, the contralateral routing of signals (CROS), makes it possible to provide amplification for persons with unilateral hearing loss. In 1967, a CROS eyeglass hearing aid was placed on government contract and made available to veterans. To study the efficiency of the CROS, a follow-up questionnaire was sent to 60 male veterans who had been fitted with this aid. All had demonstrated unilateral hearing losses, and the mean threshold for the speech frequencies (500–2000 Hz) in the good ear was 24 dB. The 54 replies (90%) indicated that 85% wore the aid, liked it, and derived benefit from it; 15% neither liked nor wore the aid. The CROS appeared to be most helpful in listening to conversational speech and at work, and most disturbing in a noisy environment. The complaints about the aid fell into major categories: 33% objected to its poor fit and construction and 11% were disturbed by speech distortion. The CROS aid has been a useful addition to the hearing-aid stock at the clinic reported here. It has expanded the program by providing amplification to veterans who could not be fitted with the conventional stock of aids.