Hearing Tests

Audiometric Test

The hearing requirement for an audiometric test is based on hearing loss only at the 500 Hz, 1,000 Hz, and 2,000 Hz frequencies that are typical of normal conversation. The test results are for an audiometer calibrated to the American National Standards Institute (ANSI) Z24.5-1951 standard. When an audiometer that is calibrated to a different standard is used, the test results must be converted to the ANSI standard. To convert International Organization for Standardization (ISO) test results to the ANSI standard, subtract from the ISO test results: 14 dB for 500 Hz, 10 dB for 1,000 Hz, and 8.5 dB for 2,000 Hz.

The area selected for testing should be free from noise that could interfere with a valid test.

  1. Record hearing test results for each ear at 500 Hz, 1,000 Hz, and 2,000 Hz (ANSI standard).
  2. Average the readings for each ear by adding the test results and dividing by 3.
  3. To pass, one ear must show an average hearing loss that is less than or equal to 40 dB.
Hearing aid:

When a hearing aid is to be worn during audiometric testing, an audiologist or hearing aid center should perform the test using appropriate audiometric equipment.

Forced Whisper Test

A hearing aid may be worn while testing. When a hearing aid is used to qualify, the hearing aid must be worn while driving.

The testing area should be free from noise that could interfere with a valid test. Measure and mark the five-foot passing distance.

Right ear examination:
  1. Have the driver cover the left ear.
  2. Stand to the side or behind the driver to eliminate visual cues.
  3. From the measured five-foot distance from the right ear, exhale fully and then whisper a sequence of words, numbers, or letters. (Avoid using only s-sounding words.)
  4. Ask the driver to repeat the whispered sequence.
  5. To pass, the driver must respond correctly.

Repeat the procedure for the left ear, making sure that the right ear is covered and that you are positioned the measured five-foot distance from the left ear.

Complete the forced whisper test for both ears, whether or not the initial test result meets the hearing requirement.