Speech-in-noise perception of children using cochlear implants and FM systems

FM systems are widely used by children wearing cochlear implants, however there have been few studies of the benefit FM systems provide. This study investigated the speech-in-noise perception of fourteen children aged between 7 and 17 years who use a cochlear implant. Their speech perception was measured using the Hearing in Noise Test (HINT), a test of open-set sentence perception. The signal-to-noise ratio was varied from 0 to -3 dB and a recording of actual classroom noise was used as the background noise. Noise was presented from four loudspeakers at 45°, 135°, 225°, and 315° azimuth to simulate classroom listening conditions. Significant FM benefit was found for the 0 and -3 dB SNR conditions. There was an interaction between subject age and FM benefit, with older children showing greater benefit. Younger children had more varied test results. Nine subjects (64%) had a measurable FM advantage based on HINT sentence scores. A small increase in noise level of 3 dB had a negative effect on speech perception, and the use of an FM system helped to counter this effect in most of the children.