TACTILE RESPONSE

TACTILE RESPONSES

Patient with profound hearing loss who unable to hear the signal being presented might still respond if they sense the vibrations that produced by the bone vibrator or earphones (Nober, 1970). The tactile responses usually occur at low frequencies where our skin is more sensitive to vibration. 

 

Tactile responses can cause 2 problems. 

First problem:

The tactile responses can give wrong impression to the patient's hearing thresholds. For example, the tactile threshold at 250Hz is at 80dB HL but patient actual hearing threshold would have been 90 dBHL or no response. 

Second problem:

The tactile response can create an artificial air-bone gap (A-B gap), thus a sensorineural hearing loss would appear to be mixed hearing loss. For example, suppose a patient should have 70 dBHL sensorineural hearing loss. A tactile response to bone conduction threshold at 40 dBHL could give wrong impression that patient would be have mixed hearing loss. Thus we need to ask the patient if the stimulus was heard (can diagnose as mixed hearing loss) or felt (can diagnose as sensorineural).

Reference: 

 1) Gelfand, S. (2009). Essentials of Audiology. (3rd Edition). New York, NY: Thieme.