Extended high-frequency audiometry

Extended high-frequency audiometry is a hearing test that goes above the 8 kHz ceiling of the standard audiogram. It may explain more of why some people struggle to follow conversation in a noisy room despite a "normal" test, but the best data come from a single study not yet peer-reviewed, and no guideline covers it yet.

If you struggle in noisy rooms but pass a standard hearing test, ask for extended high-frequency audiometry — it isn't part of routine testing, so expect to ask.

What it is

A standard hearing screen averages your thresholds at four pitches, 0.5, 1, 2 and 4 kHz, a figure called the four-frequency pure-tone average (PTA4). A full standard audiogram stops at 8 kHz. Extended high-frequency audiometry keeps going, typically out to 16 or 20 kHz, and picks up damage at the base of the cochlea, the end that handles the highest pitches, which the standard test cannot see.

The symptom it is meant to explain is the one most adults with hearing trouble actually complain about: not being able to follow a conversation in a noisy restaurant.

The main evidence: one preprint

The sharpest data come from the Swedish Tinnitus Outreach Project (STOP), which tested 526 ears in 263 adults aged 20–84 without tinnitus.^[1]

The standard four-pitch average explained roughly 19–25% of the differences between people in speech-in-noise scores.
Thresholds at 10–16 kHz explained about 34–36%.
The best models still left roughly two-thirds of the variation unexplained.

That is a real advantage, not a transformation. The study is also the work of a single author, cross-sectional, not yet peer-reviewed, and drawn from a highly educated Swedish sample tested at a single noise level, so read the figures as provisional.

A widely quoted pair, "64% versus 16%", comes from the same preprint but measures something else: how strongly each test tracks age. Extended high-frequency thresholds are the most age-sensitive hearing measure in that group; the pair says nothing about speech in noise.

In the clinic

Among 40 adults who complained of hearing trouble despite normal standard audiograms, 25 turned out to have hearing loss above 8 kHz. That was a retrospective case series, and its authors say plainly that no evidence-based protocol for this testing exists yet.^[2]

The main US guideline on age-related hearing loss, from the American Academy of Otolaryngology–Head and Neck Surgery Foundation, does not mention extended high-frequency testing at all.^[3] It isn't part of routine testing, so expect to ask for it.

"Hidden hearing loss" is contested

The other popular explanation for trouble in noise with a normal audiogram is cochlear synaptopathy, often called hidden hearing loss: the loss of synapses between the inner ear's hair cells and the auditory nerve. The evidence runs both ways.

In the STOP group, the usual stand-in for synapse loss, the size of the first wave of the auditory brainstem response (ABR wave I amplitude), showed no link to speech scores in a subsample of about 140 ears. The timing of that wave (its latency) did, modestly (about 12% of the variation), and mainly in older adults, which the author reads as slower nerve conduction rather than lost synapses, while noting the finding needs validation.^[4]
A 2025 study that combined middle-aged people with an animal model, and confirmed nerve degeneration under the microscope in the animals, found that degeneration does add to difficulty in noise and to listening effort.^[5]
A 2026 study of 60 adults with normal audiograms found neither synapse loss nor extended high-frequency loss independently linked to difficulty in noise.^[6]

Part of the problem is measurement: wave I amplitude is a weak, noisy proxy, so a null result for it is not a null result for synapse loss. Anyone stating the cause of hidden hearing loss confidently, in either direction, is ahead of the data.

What to do

If you struggle in noise despite a normal audiogram, ask for extended high-frequency audiometry, and for a speech-in-noise test.
Treat a result above 8 kHz as a possible contributor, not a full explanation. It suggests where some of the damage is; the practical steps — protecting your ears from noise and treating loss that affects daily life — are on Hearing.
See a clinician promptly, whatever the audiogram shows, if hearing dropped suddenly, is much worse in one ear, or comes with pain, discharge, ringing in one ear only, or vertigo.