Power tools are taught that may include, for example, a detector for detecting impact sounds generated, e.g. by a hammer strikes an anvil or by oil pulse from an oil unit. The detector may include a receiver (30) adapted to selectively convert sound within a narrow frequency range into electric signals. Preferably, the impact sounds fall within the narrow frequency range of the receiver (30). A processor 38 may be utilized to control the motor (22) in order to stop the rotation of the hammer when a pre-determined number of impact sounds has been detected by the detector. In addition or in the alternative, various structures can be used to set various operating conditions, including dials 34, sound sensors 30, keypads and remote control devices 250. Further, structures for performing maintenance condition status checks are taught.