Interactive Teaching Atlas

Cortical Responses

A self-contained guide to the cortical auditory evoked potential — the cortex's own answer to sound — and how it is used to estimate hearing thresholds objectively and to confirm that amplified speech is audible. Built for students, trainees and clinicians.

The cortical auditory evoked potential (CAEP) is the slow, late electrical response of the auditory cortex to sound, recorded from the scalp 50–300 ms after a stimulus. Because it certifies that sound has reached and been processed by the cortex — in an awake, non-attending listener — it underpins objective audiometry, medicolegal threshold confirmation and the validation of infant hearing-aid fittings. New here? Begin with Generators & Neuroanatomy, then work through the waveform, technique, threshold estimation, interpretation and maturation. Use the reader-level selector in the sidebar to pitch every explanation at Foundation, Trainee or Clinician depth.
0100200300400latency (ms after stimulus onset)+−amplitude (µV)stimulus onP1N1P2N2
The obligatory cortical response. P1, N1, P2 and N2 unfold across the first 50–300 ms after a sound — far later and far larger than the brainstem response. In the awake adult the N1–P2 swing dominates and is the feature tracked for objective audiometry. Vertex-positive plotted upward; latencies are typical adult values and vary with stimulus and state. Schematic — not to scale.

Explore the atlas

Start here

Generators & Neuroanatomy

Where the response comes from — the ascending pathway, the thalamocortical generators and the auditory cortex behind the late latency response.

The Atlas

The P1–N1–P2 Complex

The obligatory components, their latencies and polarity, and the acoustic change complex that signals discrimination within a sound.

The Atlas

Recording Technique

Electrode montage, tone and speech-token stimuli, arousal state, free-field testing, averaging and artefact control.

The Atlas

Threshold Estimation (CERA)

Objective audiometry from the cortical response, near-threshold morphology, and the medicolegal and aided-audibility applications.

The Atlas

Interpretation & Detection

Present, absent and equivocal responses, and the move from visual reading to automated statistical detection.

The Atlas

Maturation & Development

P1 latency as a biomarker of central auditory maturation, the sensitive period and what a delayed P1 means.

Reference

Glossary

Concise definitions of the key terms in cortical response audiometry, with aliases and cross-links.

Reference

References

The peer-reviewed and authoritative sources behind every claim in the atlas.

The applications

Each application page pairs the characteristic cortical-response picture with the clinical question it answers, the reason the test is chosen, and the single teaching point to carry away.

Non-organic Hearing Loss

Auditory Neuropathy (ANSD)

Infant Hearing-Aid Validation

Cochlear Implant Candidacy & Outcome

Objective Threshold Estimation

Suprathreshold Discrimination (ACC)

Central Maturation Monitoring

Functional Hearing Loss in Children

Complex Needs & Developmental Delay

Practise

Interactive

Response Simulator

Drive stimulus level, residual noise and arousal, and watch the N1–P2 and the present/absent verdict respond.

Interactive

Compare Signatures

Place any two cortical-response signatures side by side and read how their shapes differ.

Interactive

Clinical Cases

Eight worked cases — read the vignette and findings, commit to an answer, then check your reasoning against the teaching point.

Interactive

Pattern Trainer

An endless stream of generated traces to classify as present, equivocal or absent.

Interactive

Self-Assessment

A 24-question single-best-answer bank with browse, spaced-repetition and timed modes.