1. Interpretation Normal acoustic reflex threshold
Elevated acoustic reflex threshold
Lowered acoustic reflex threshold
Absent acoustic reflex 1

2. Acoustic reflex results: Patterns2

3. Objective tests of the auditory system
Acoustic immittance measures
Static acoustic compliance
Tympanometry
Acoustic reflex
Otoacoustic emissions (OAE)
Transient-evoked OAE (TEOAE)
Distortion-product OAE (DPOAE)
Auditory evoked potentials
Electrocochleography (ECog)
Auditory brainstem response (ABR)
Auditory middle latency response (AMLR)
Auditory late response (ALR) 3

4. Otoacoustic emissions
Sounds generated by the cochlea and recorded in the external auditory meatus.
By-product of the active non-linear cochlea.
Conductive pathway must be normal for OAEs to be recorded.
Types:
Spontaneous (SOAE)
Evoked: Distortion-product OAE (DPOAE)
Transient-evoked OAE (TEOAE) 4

5. Occur in many normal ears Level: About 10 dB TEOAE
Spontaneous OAE
Occur in many normal ears
Level: About 10 dB
TEOAE
Transient sounds like clicks or tone-bursts.
Present many stimuli (260 to 500).
Average responses to separate emissions from the noise floor.
DPOAE
Two pure tones (f1 and f2) that vary in frequency.
Cochlea produces additional tones called distortion products.
Does not require as many stimulus repetitions and averaging as TEOAE 5