GSI AudioStar Pro™ Clinical Audiometer
82
D-0100778 Rev C
Tone Decay Test
Carhart Tone Decay Test (1957)
Patients with retrocochlear pathology of the eighth nerve exhibit a rapid
“abnormal auditory adaption” or “temporary threshold drift” in response to a
continuous pure tone presentation.
Presentation Level
Establish the patient’s hearing threshold for the test ear using earphones
or insert phones using a pulsed tone.
Set the intensity for the selected channel to 0 dB SL (or 20 dB SL to
present an easier listening task). The Interrupt pushbutton may be
selected or the Tone bar may be manually depressed for the duration of
the test.
Test Instructions
Instruct the patient to depress the hand switch as soon as a tone is heard,
and to release the hand switch only when the tone becomes inaudible.
Test Procedure
Select Tone Decay from the More Tests Menu.
Present the continuous tone at the selected intensity.
When the patient responds by pressing the patient response button, the
timer will start. The timer may be manually started by pressing the Start
pushbutton of the scorer/timer.
When the patient releases the patient response button, the timer will
pause. If the patient pushes the response button again, the timer will
resume.
Record the number of seconds the tone sustains audibility.
If the tone becomes inaudible before the minute criteria is met, without
interrupting the tone presentation, raise the intensity in 5 dB steps until
the tone is heard for a full minute.
Reset the time at each increase in intensity level. Continue this procedure
until the tone is heard for a full minute, or until an intensity of 40 dB SL
is reached.
