An acoustic monitoring system includes a portable acoustic detection device, a sound analysis device and a confidence level device. The portable acoustic detection device is capable of receiving sound at one or more locations near a sound-producing device. The sound analysis device receives the sound from the portable sound detection device, determines a diagnosis based on a comparison between the sound and pre-recorded sound data, and outputs the diagnosis to the portable acoustic detection device. The sound analysis device also determines a corrective action for inhibiting the sound, which is also output to the portable sound detection device. The confidence level device determines a confidence level of the diagnosis indicating a likelihood that the diagnosis is successfully diagnosed.