Assessment of Auditory Function
Pure-tone and speech audiometry
Know transducer corrections, calibration concepts, and interpretation. Air-bone gaps indicate conductive components; no gap with elevated thresholds indicates sensorineural. Traps include misreading masking rules and confusing dB HL with dB SPL. Know the speech recognition/intelligibility distinction and rollover (performance worsens at high presentation levels, suggesting retrocochlear involvement).
Immittance and acoustic reflexes
Tympanometry types (A, As, Ad, B, C) and their meanings; static admittance; acoustic reflex pathways (ipsilateral and contralateral). A common trap is treating a type B tympanogram as always effusion-it can also reflect a perforation or a probe against the canal wall. Reflex decay and elevated/absent reflexes suggest retrocochlear or neural pathology.
Otoacoustic emissions and evoked potentials
OAEs reflect outer hair cell function; TEOAEs and DPOAEs differ in frequency range and stimulus. ABR waves (I, III, V) and their generators; wave V latency-intensity functions; ECochG for Ménière's; ASSR for frequency-specific thresholds. Trap: ABR threshold estimates are not the same as behavioral thresholds.
Vestibular and central assessment
Know VNG/caloric interpretation, vHIT, and the difference between peripheral and central findings (e.g., direction-fixed vs. direction-changing nystagmus).
Worked rule of thumb: For masking, apply the plateau method conceptually: add masking to the non-test ear until the threshold stops shifting, then stop-overmasking occurs when cross-hearing of the masking noise elevates the test-ear threshold.