A portable diagnostic instrument for use by medical professionals. The portable diagnostic instrument can comprise a control unit that can maintain the frequency of sound or vibration produced by the device constant, even when battery power is reduced. The control unit can also comprise a warning unit to provide information about remaining battery life to the user. Furthermore, the portable diagnostic instrument can comprise a unit capable of producing vibration and a unit capable of producing sound at differing frequencies. The device can produce both the sound and vibration at the same time or each can be operated individually. Moreover, the device is capable of being attached to other medical equipment that is carried by a medical professional or can be easily kept in a pocket, so that it is readily available when needed.
