CDIS 3370: Physiologic Tests of the Auditory System Flashcards

Vocabulary flashcards covering objective auditory testing, tympanometry classifications, acoustic reflexes, otoacoustic emissions, and auditory evoked potentials.

Subjective Testing

Auditory testing that relies on the patient actively responding and telling the clinician when and what they hear.

Objective Testing

Audiometric testing that evaluates various components of the auditory system without requiring any response from the patient.

Tympanometry

A component of the impedance audiometry battery that measures changes in middle-ear compliance (mobility) as a function of varied air pressure.

Middle-Ear Pressure

The air pressure at which maximum compliance (the peak) is observed on a tympanogram, measured in decaPascals ($daPa$).

Compliance (Tympanometry)

The height of the peak on a tympanogram representing how much the eardrum moved, measured in $cm^3$ (or cc).

External Ear Canal Volume

An estimate of the volume of the external ear canal measured in $cm^3$ (or cc), which helps identify ear canal obstructions or tympanic membrane perforations.

Type A Tympanogram

A normal tympanogram curve reflecting normal middle-ear pressure ($-100$ to $+50\,daPa$ in adults) and normal compliance.

Type B Tympanogram

A flat tympanogram lacking a discernable peak in pressure or compliance, commonly caused by fluid in the middle ear.

Type C Tympanogram

A tympanogram exhibiting negative middle-ear pressure beyond $-100\,daPa$ in adults or $-150\,daPa$ in children, with normal compliance.

Type As Tympanogram

A tympanogram displaying normal middle-ear pressure but reduced compliance ('A-stiff'), often indicating a stiffened middle ear system like stapes fixation.

Type Ad Tympanogram

A tympanogram showing normal middle-ear pressure with abnormally high compliance, often caused by hypermobile eardrums or ossicular disarticulation.

Acoustic Reflex

The involuntary bilateral contraction of the stapedius muscle in response to an intense acoustic stimulus, which stiffens the middle ear system and decreases compliance.

Acoustic Reflex Threshold

The lowest sound intensity level at which an acoustic reflex can be detected, normally ranging between $85$ and $100\,dB\text{ SPL}$.

Otoacoustic Emissions (OAEs)

Low-intensity sounds generated by the cochlea as a result of outer hair cell motility (expanding and contracting), recorded in the external ear canal.

Spontaneous Otoacoustic Emissions

Otoacoustic emissions emitted naturally by the cochlea without external acoustic stimulation; present in about half of normal-hearing individuals but not used clinically.

Evoked Otoacoustic Emissions

Otoacoustic emissions produced by the cochlea in direct response to acoustic stimuli, serving as a clinical measure of outer hair cell function.

Transient-Evoked Otoacoustic Emissions (TEOAEs)

Evoked otoacoustic emissions elicited by brief acoustic stimuli, such as clicks or tone pips.

Distortion-Product Otoacoustic Emissions (DPOAEs)

Evoked otoacoustic emissions elicited by two primary pure tones played simultaneously, causing a healthy cochlea to generate energy at a predictable difference frequency.

Auditory Evoked Potentials

Measurements of changes in ongoing electrical activity in the brain (via EEG) generated along the auditory neural pathway in response to sound stimuli.

Latency (Evoked Potentials)

The time interval that elapses between the introduction of an auditory stimulus and the occurrence of an evoked potential response peak.

Amplitude (Evoked Potentials)

The strength or magnitude of an auditory evoked potential response wave.

Electrocochleography (ECoG)

An auditory evoked potential procedure measuring cochlear electrical potentials within $0$ to $2\,ms$ post-stimulus, used primarily for intraoperative monitoring and diagnosing Meniere's disease.

Auditory Brainstem Response (ABR)

An auditory evoked potential recorded $1$ to $15\,ms$ post-stimulus that reflects electrical activity along the 8th nerve and brainstem auditory pathways.

Wave V (ABR)

The most prominent ABR wave generated primarily by the inferior colliculus; it persists at the lowest sound levels and is used to estimate hearing threshold.

Middle Latency Response (MLR)

An auditory evoked potential recorded $16$ to $60\,ms$ post-stimulus from the high brainstem and auditory cortex, affected by state of consciousness and used to evaluate auditory processing.

Auditory Late Responses

Auditory evoked potentials (such as P1, N1, P2, N2) recorded after $60\,ms$ post-stimulus in the auditory cortex, influenced by alertness and cognitive attention.