The purpose of this investigation was to study the effectiveness of different "noise reduction" circuits for subjects of differing degrees, configurations, and experience with amplification. Fifty subjects with hearing impairment were randomly assigned one of four circuit types whose marketing claims suggested resultant improvement in speech recognition in noise backgrounds. Although no apparent circuit superiority was shown, the subjects indicated a high level of satisfaction with the hearing aids chosen for them. Improved measuring tools, improved fitting strategies, and overall improved hearing-aid circuitry (though probablynotthe noise reduction feature) may explain this level of satisfaction.