Abstract: A portable hearing tester to test the temporary hearing threshold shift of an individual. The portable hearing tester has a bone vibrator coupled to a discrete tone generator which is applied to a person's external skull. The bone vibrator is preferably gripped in the teeth. An alternative embodiment of the present invention uses a bone vibrator on the mastoid or forehead. The discrete tones generated through the bone vibrator can be heard by the person to test their current hearing threshold. Between 2 to 12 tones will be played for the person to hear. If the person cannot hear the selected tones at a specific decibel level which could be heard before, then that indicates a hearing threshold shift. Alternatively, discrete levels at one tone can be presented. The person need only count the number of distinct levels heard when the number of tones is reduced. When that number decreases it indicates a hearing threshold shift.