The difficulty of understanding speech with background noise is perceived as one of the main disabilities of the hearing aids users. The purpose of this study was to compare the hearing performance of subjects with sensorioneural, bilateral, light to moderate degree hearing loss with the microphones omnidirectional, fixed directional mode and automatically activated adaptive directional mode, activated through the signal/noise ratio (S/R) in which the Sentence Recognition Threshold in Noise are obtained. It was used the hearing aid Reach, RCH62, Beltone in omnidirectional, fixed directional and automatically activated adaptive microphone modes. The following presentations of acoustic stimulus had been tested: speech 0° azimuth and noise 180° azimuth (0°/180°), speech 90° azimuth and noise 270° azimuth (90°/270°) and speech 270° azimuth and noise 90° azimuth (270°/90°). The average signal to noise ratio ranged from 6,6 dB to -6,9 dB. The microphone that had the best average for signal to noise ratio, considering the three conditions of stimulus presentation, was the automatically activated adaptive. However, because it is a small sample, there was great individual variability. Further studies should be performed to obtain scientific support for the most appropriate selection of microphones.