Auditory Evoked Potentials

Objective assessment of auditory pathway function from cochlea to cortex.

Auditory Evoked Potentials are objective electrophysiological tests used to evaluate auditory pathway function at different neural levels. These tests provide critical information about hearing sensitivity and neural integrity, especially in infants, young children, and individuals who cannot provide reliable behavioral responses.

Auditory Brainstem Response (ABR)

Auditory Brainstem Response is a non-invasive diagnostic procedure that evaluates how acoustic signals travel from the cochlea to the brainstem. Surface electrodes are placed on the scalp and near the ears while auditory stimuli, such as clicks or tone bursts, are delivered through headphones. The patient must remain still, and the test is painless. For infants and young children, ABR is most reliable when performed during deep natural sleep or under sedation, as movement can interfere with accurate recordings. Clinically, ABR is essential for newborn hearing screening, assessing auditory nerve integrity, and detecting retrocochlear or neurological pathologies.

Auditory Middle Latency Response (AMLR)

Auditory Middle Latency Response records neural activity originating from the thalamus and early cortical regions in response to sound. Electrodes capture responses that occur slightly later than those measured in ABR. AMLR is particularly useful for evaluating central auditory pathways and identifying auditory processing disorders, providing insight into midbrain auditory function.

Auditory Late Response (ALR)

Auditory Late Response measures cortical activity related to auditory perception. Patients remain alert while listening to auditory stimuli, and electrodes record cortical responses. ALR provides valuable information about higher-level auditory processing, including attention, discrimination, and perception, making it useful in cases where cortical involvement is suspected.

Auditory Steady-State Response (ASSR)

Auditory Steady-State Response determines frequency-specific hearing thresholds using continuous modulated tones. The patient listens passively while electrodes record brain responses. ASSR is especially valuable for infants, young children, or patients unable to participate in behavioral audiometry, as it provides objective threshold estimates across multiple frequencies.