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When asking individuals with hearing impairment to identify the situations for which the most com-munication difficulty is encountered, listening in nioise seems to be nearly universally mentioned. In fact, I would venture that if queried, almost no patient would refuse the offer of improved levels for sounds of interest in relation to the level of background noise. Improving the signal-to-noise ratio (SNR) for listeners with hearing impairment has long been a goal of various amplification schemes. The reasons for attempting to improve the SNR delivered to hearing aid wearers are ob-vious given clear evidence of reduced speech recognition with increasingly less favorable SNRs. Moore (1989) suggested that individuals with normal hearing require a SNR of at least +6 dB for satisfactory communication. Unfortunately, data overwhelmingly show that individuals with sensorineural hearing loss generally require even more favorable SNRs for satisfactory communica-tion than listeners with normal hearing (Carhart
Todd A. Ricketts (Sat,) studied this question.