Advanced Procedures in Audiology

CSD670 / Spring 2004

How to Conduct an Audiometric Threshold Search

1. Set up and check audiometer, place earphones on patient and provide instructions.

2. Test best ear first. If no difference, test right ear first.

3. Test frequencies (Hz) in the following order:
1000, 2000, 4000, 8000, 500, 250, 1000*
* Recheck of 1000 Hz should be within ± 5 dB of first 1000 Hz response.

4. Determining Threshold.

A. Finding the starting point for your search.
• Present a tone at 30 dB HL
• If they respond, descend in 10 dB steps until the person does not respond. This is your starting point for your threshold search.
• If they DO NOT respond, ascend to 50 dB and then in 10 dB increments until they respond. Subtract 10 dB from this value. This is your starting point for your threshold search.

B. Searching for Threshold
•Present tone. If they respond descend in 10 dB steps until they no longer respond.
• If they DO NOT respond, ascend in 5 dB steps until they respond. This is the first ascending response.
• Descend by 10 dB an repeat the first two steps until three ascending responses at the same level are found. Remember, down by 10, up by 5.
•Threshold is defined as the lowest intensity that three ascending responses are found. It is not necessary the three ascending responses be consecutive.