It is well known that in reverberant environments, the human auditory system has the ability to pre-process reverberant signals to compensate for reflections and obtain effective cues for improved recognition. In this study, we propose such a preprocessing technique for combined detection and enhancement of speech using a single microphone in reverberant environments for distant speech applications. The proposed system employs a framework where the target speech is synthesized using continuous auditory masks estimated from sub-band signals. Linear gammatone analysis/synthesis filter banks are used as an auditory model for sub-band processing. The performance of the proposed system is evaluated on the UT-DistantReverb corpus which consists of speech recorded in a reverberant racquetball court (T60~9000 msec). The current system shows an average improvement of 15% STNR over an existing single-channel dereverberation algorithm and 17% improvement in detecting speech frames over G729B, SOHN & Combo-SAD unsupervised speech activity detectors on actual reverberant and noisy environments.