ABR Testing: What It Is and Why It’s Important

Auditory Brainstem Response (ABR) testing is a crucial tool in audiology, allowing clinicians to assess hearing and neurological function in people of all ages. Whether used for new-born hearing screenings, diagnosing auditory disorders, or identifying nerve-related hearing issues, ABR testing plays a vital role in understanding how sound travels from the ear to the brain.

In this blog, we’ll explore what ABR testing is, how it works, who it’s for, and what to expect during the procedure.

What Is ABR Testing?

Auditory Brainstem Response (ABR) testing is a non-invasive hearing test that measures how the auditory nerve and brainstem respond to sound. Unlike standard hearing tests, which require active participation from the patient, ABR testing is objective, meaning it doesn’t rely on a person’s response.

Because of this, ABR testing is especially useful for:
✔ Newborn and infant hearing screening
✔ Diagnosing hearing loss in people who cannot complete traditional hearing tests
✔ Detecting auditory nerve and brainstem disorders (such as auditory neuropathy or vestibular schwannomas)

ABR testing provides critical information about the hearing system, particularly how sound signals are transmitted from the inner ear to the brain.

How Does ABR Testing Work?

ABR testing records the electrical activity of the auditory nerve and brainstem in response to sound. Here’s how the process works:

1️⃣ Electrodes Are Placed – Small electrodes are attached to the patient’s forehead and behind the ears. These detect the brain’s responses to sound.

2️⃣ Headphones or Ear Inserts Deliver Sound – A series of clicking sounds or tone bursts are played into the patient’s ears.

3️⃣ Brain Activity Is Measured – The electrodes pick up the electrical signals from the auditory nerve and brainstem, which are recorded and analyzed by a computer.

4️⃣ Results Are Reviewed – The audiologist examines the response patterns to determine how well sound is traveling from the ear to the brain.

ABR testing typically takes 30 to 60 minutes and is completely painless and safe. Since the test measures involuntary responses, patients don’t need to do anything but relax—infants can even sleep through the test!

Who Needs ABR Testing?

ABR testing is useful for a variety of patients, including:

👶 Newborns and Infants – ABR is a key part of newborn hearing screening programs. If a baby doesn’t pass their initial screening, an ABR test can provide more detailed results to check for hearing loss.

🧑‍⚕️ Adults with Suspected Auditory Nerve Disorders – ABR testing can help detect auditory neuropathy (a condition where the auditory nerve doesn’t properly transmit sound) or rule out issues like vestibular schwannomas (acoustic neuromas), which are benign tumors on the auditory nerve.

👂 Patients Who Cannot Complete Traditional Hearing Tests – If a person is unable to respond to sounds during a standard hearing test—due to developmental conditions, cognitive impairments, or other factors—ABR testing can provide an objective measure of their hearing ability.

What Do ABR Test Results Mean?

ABR test results show a series of waveforms, each representing different parts of the auditory pathway.

✅ Normal Results – If the waveforms appear as expected, it indicates that sound is traveling properly from the ear to the brainstem.

⚠️ Abnormal Results – If the waveforms are delayed or missing, it may suggest hearing loss, auditory nerve dysfunction, or another underlying issue that requires further investigation.

An audiologist or ENT specialist will review the results and determine the next steps, whether that be hearing aids, further testing, or medical intervention.

Final Thoughts: Why ABR Testing Matters

ABR testing is a powerful diagnostic tool that helps audiologists and medical professionals understand a patient’s hearing health without needing active participation. Whether assessing new-borns, diagnosing complex auditory disorders, or identifying nerve-related hearing problems, ABR testing ensures that patients receive the earliest and most accurate diagnosis possible.