IHS Auditory Assessment 3 ā Questions and Answers
Question 1: The rollover index (RI) is calculated during which audiometric test?
- Pure-tone audiometry
- Tympanometry
- Performance-intensity function for word recognition (Correct answer)
- Auditory brainstem response
Correct answer: Performance-intensity function for word recognition
The rollover index is derived from the performance-intensity (PI) function for word recognition and is used to identify retrocochlear dysfunction when PI scores decrease significantly at high intensity levels.
Question 2: Which audiometric configuration is most consistent with noise-induced hearing loss (NIHL)?
- Flat hearing loss across all frequencies
- Notch at 4000 Hz with recovery at 8000 Hz (Correct answer)
- Low-frequency sloping loss
- Rising audiogram (better at high frequencies)
Correct answer: Notch at 4000 Hz with recovery at 8000 Hz
Noise-induced hearing loss characteristically presents as a notch at 4000 Hz (sometimes 3000ā6000 Hz) with partial recovery at 8000 Hz, reflecting the resonance properties of the ear canal.
Question 3: When should the audiologist introduce inter-aural attenuation (IA) values when deciding whether to mask?
- Whenever the patient reports difficulty hearing
- When the air-bone gap exceeds 10 dB
- When the signal presented to the test ear could cross over to the non-test ear (Correct answer)
- Only during bone conduction testing
Correct answer: When the signal presented to the test ear could cross over to the non-test ear
Masking is needed whenever the signal level in the test ear exceeds the inter-aural attenuation, meaning the signal could reach the non-test cochlea and give a false response.
Question 4: A 1000 Hz probe tone is preferred over 226 Hz for tympanometry in which population?
- Adults over 65 years
- Infants under 6 months of age (Correct answer)
- Patients with ossicular chain discontinuity
- Patients with otosclerosis
Correct answer: Infants under 6 months of age
A 1000 Hz probe tone is recommended for infants under 6 months because their highly compliant ear canals and mobile middle ear systems are better assessed at higher probe tone frequencies.
Question 5: The auditory brainstem response (ABR) Wave V is generated primarily by which structure?
- Cochlear hair cells
- Cochlear nucleus
- Inferior colliculus (Correct answer)
- Lateral lemniscus
Correct answer: Inferior colliculus
Wave V of the ABR is thought to originate predominantly from the inferior colliculus (midbrain), and it is the most robust and clinically important wave for threshold estimation.
Question 6: Absolute latency prolongation of ABR Wave I with a normal Wave V suggests pathology at the level of:
- The auditory cortex
- The cochlea or auditory nerve distally (Correct answer)
- The inferior colliculus
- The medial geniculate body
Correct answer: The cochlea or auditory nerve distally
Prolonged Wave I with a normal Wave V (normal IāV interval) localizes the pathology to the peripheral auditory system ā the cochlea or distal auditory nerve.
Question 7: Which test provides frequency-specific threshold information using physiological measures without behavioral responses?
- Auditory brainstem response (click ABR)
- Auditory steady-state response (ASSR) (Correct answer)
- Acoustic reflex thresholds
- Distortion product OAEs (DPOAEs)
Correct answer: Auditory steady-state response (ASSR)
The auditory steady-state response (ASSR) uses modulated tones at specific frequencies to estimate frequency-specific hearing thresholds objectively without requiring behavioral responses.
IHS Auditory Assessment 3
The rollover index (RI) is calculated during which audiometric test?