Place any two conditions side by side to see exactly where their reflex signatures, decay behaviour and audiograms diverge.
outer/middle
Otosclerosis
Stapes fixation — reflex absent on the probe side from the start
Reflex grid
Stim. Right
Stim. Left
Probe Right
Absent
Absent
Probe Left
Present
90 dB HL
Present
85 dB HL
Reflexes are absent for both conditions recorded with the probe in the affected ear, and present for both conditions recorded with the probe in the healthy ear — a vertical 'probe-ear' pattern.
Decay
Negative (normal) decay — amplitude is well maintained across the 10-second hold.
Audiogram
○ Right ear✕ Left ear
Right ear: low-frequency conductive loss with an air–bone gap and a Carhart notch around 2 kHz. Left ear normal.
retrocochlear
Vestibular Schwannoma
Eighth-nerve tumour — elevated or absent reflexes with abnormal decay
Reflex grid
Stim. Right
Stim. Left
Probe Right
Elevated
110 dB HL
Present
90 dB HL
Probe Left
Absent
Present
95 dB HL
Stimulating the affected (right) ear gives elevated or absent reflexes in both probe positions; stimulating the healthy ear gives normal reflexes — a horizontal 'stimulus-ear' pattern.
Decay
Positive (abnormal) decay — amplitude reaches 50% at about 7.1 s.
Audiogram
○ Right ear✕ Left ear
Right ear: asymmetric high-frequency sensorineural loss. Asymmetry is the cardinal audiometric clue.
These conditions differ in site of lesion (outer/middle versus retrocochlear), which is reflected in the shape of each reflex grid.