IHS Audiometric Testing Procedures 2 — Questions and Answers
Question 1: What is the purpose of masking during pure-tone audiometry?
- To amplify the test signal in the test ear
- To prevent the non-test ear from responding to cross-heard signals (Correct answer)
- To reduce ambient noise in the test booth
- To calibrate the audiometer before testing
Correct answer: To prevent the non-test ear from responding to cross-heard signals
Masking introduces narrow-band noise to the non-test ear to prevent it from detecting signals intended for the test ear via cross-hearing.
Question 2: Which audiometric symbol is used to represent unmasked bone conduction thresholds for the left ear?
- >
- <
- [ (Correct answer)
- ]
Correct answer: [
The bracket '[' pointing right represents unmasked bone conduction thresholds for the left ear on a standard audiogram.
Question 3: At what interaural attenuation level should a hearing specialist typically apply masking for air conduction testing?
- 10 dB
- 20 dB
- 40 dB (Correct answer)
- 60 dB
Correct answer: 40 dB
Masking is generally applied when the air conduction signal in the test ear exceeds the bone conduction threshold of the non-test ear by 40 dB or more.
Question 4: What does a 'shadow curve' on an audiogram indicate?
- Normal hearing in both ears
- The non-test ear responding to stimuli meant for the test ear (Correct answer)
- Calibration error in the audiometer
- Presence of a conductive hearing loss
Correct answer: The non-test ear responding to stimuli meant for the test ear
A shadow curve appears when the non-test ear responds to cross-heard signals, mimicking the test ear's response and giving falsely better thresholds.
Question 5: Which test technique is used to determine the softest level at which a patient responds 50% of the time?
- Ascending technique only
- Descending technique only
- Modified Hughson-Westlake procedure (Correct answer)
- Loudness balance procedure
Correct answer: Modified Hughson-Westlake procedure
The modified Hughson-Westlake ascending technique systematically finds the threshold at which the patient correctly identifies the tone 50% of the time.
Question 6: What is the typical frequency range tested during a standard pure-tone audiometric evaluation?
- 125 Hz to 4,000 Hz
- 250 Hz to 8,000 Hz (Correct answer)
- 500 Hz to 6,000 Hz
- 1,000 Hz to 10,000 Hz
Correct answer: 250 Hz to 8,000 Hz
Standard audiometric evaluation tests octave frequencies from 250 Hz through 8,000 Hz, capturing the speech frequency range and beyond.
Question 7: How many correct responses out of how many presentations are typically required to establish a threshold in the ascending technique?
- 1 out of 2
- 2 out of 3 (Correct answer)
- 3 out of 5
- 2 out of 4
Correct answer: 2 out of 3
Threshold is established when the patient responds correctly to 2 out of 3 presentations at the same level using the ascending approach.
IHS Audiometric Testing Procedures 2
What is the purpose of masking during pure-tone audiometry?