How to read a hearing test report: your audiogram and tympanogram, explained

A hearing test ends with a sheet of paper that looks like a graph someone forgot to finish: two lines of Xs and Os, a few brackets, a curve in a box, and a line of abbreviations at the bottom. The ENT doctor reads it in seconds. Most patients fold it into a file and never look at it again.

It is worth looking at. An audiogram is one of the few medical reports you can learn to read in ten minutes, and once you can, you will understand what your doctor is telling you, why a hearing aid was or was not suggested, and what to compare next year. This article walks through the parts of a typical hearing test report in India. It does not replace your ENT doctor’s reading of your own report.

What a hearing test usually includes

A “hearing test” at an ENT clinic or audiology centre is usually a set of tests, printed together:

• Pure-tone audiometry. You sit in a quiet booth with headphones and press a button each time you hear a beep. This produces the audiogram, the graph most of this article is about.
• Bone conduction. A small vibrator is placed on the bone behind your ear and the beeps are repeated. Comparing this with the headphone results tells the doctor where a hearing problem sits.
• Tympanometry. A soft probe in the ear canal changes the air pressure slightly and measures how the eardrum moves. It prints as a small curve, usually on the same report.
• Speech tests. Sometimes you are asked to repeat words played at different volumes.

Your doctor may also do a quick tuning fork test in the consulting room. Newborns and young children are screened with different tests, which are not covered here.

Reading the audiogram

The two axes

The audiogram is a grid.

• Across the top, left to right, is pitch, measured in hertz (Hz). It usually runs from 250 Hz, a low hum, to 8,000 Hz, a high whistle. Most of the sounds that make speech clear, such as “s”, “f” and “th”, sit at the higher end.
• Down the side is loudness, in decibels of hearing level (dB HL). This is the part that confuses people: quiet is at the top and loud is at the bottom. Each mark shows the quietest beep you could hear at that pitch. The lower a mark sits on the chart, the louder the sound had to be before you heard it.

So a line that runs across the top of the grid is good hearing. A line that sinks towards the bottom is hearing loss.

The symbols

Most reports in India follow the common convention:

Symbol	Ear	Test
O (often red)	Right	Through headphones (air conduction)
X (often blue)	Left	Through headphones (air conduction)
< or [	Right	Through bone (bone conduction)
> or ]	Left	Through bone (bone conduction)

An arrow hanging from a symbol means you did not hear the beep even at the loudest level the machine could play. Conventions vary between machines, so check the key printed on your report.

How hearing loss is graded

To give one number for each ear, the beeps at the main speech pitches are averaged. This is the pure-tone average, or PTA. Many reports in India average three pitches (500, 1,000 and 2,000 Hz). The World Health Organization’s grading averages four, adding 4,000 Hz, so the two methods can differ by a few decibels for the same ear.

The WHO grades, by the average in the better-hearing ear:

Grade	Average threshold
Normal hearing	Better than 20 dB
Mild	20 to under 35 dB
Moderate	35 to under 50 dB
Moderately severe	50 to under 65 dB
Severe	65 to under 80 dB
Profound	80 to under 95 dB
Complete	95 dB or worse

The grade is a starting point, not the whole story. Two people with the same average can struggle very differently, depending on which pitches are affected and how well the brain separates speech from background noise.

Where the problem is: conductive, sensorineural or mixed

This is where the bone conduction brackets earn their place.

• Conductive hearing loss. Bone conduction is near normal, but the headphone results are worse. The gap between them is called the air-bone gap. Sound is being blocked on its way in, in the ear canal or the middle ear: wax, fluid behind the eardrum, a perforation, or a problem with the small bones of the middle ear. Many of these can be treated.
• Sensorineural hearing loss. Both lines sit together, and both are down. The problem is in the inner ear or the hearing nerve. Age-related hearing loss and noise damage are the commonest causes. This is the kind usually helped by hearing aids.
• Mixed hearing loss. Both lines are down, with a gap between them as well.

Shapes worth knowing

A few patterns come up often enough that it helps to recognise them:

• A slope down to the right. Hearing is better at low pitches and worse at high ones. This is the typical shape of age-related hearing loss. People with it often say they can hear that someone is talking but cannot make out the words.
• A dip around 4,000 Hz that recovers at 8,000 Hz. Often called a noise notch. It is commonly seen after years of loud noise, at work, from music through earphones, or from firecrackers.
• One ear much worse than the other. Unequal hearing that has no obvious cause, such as wax or an ear infection, is usually investigated further. Your doctor may suggest more tests.

Reading the tympanogram

The tympanogram is the small curve, usually with a letter written beside it. It describes how freely the eardrum moves.

• Type A: a normal peak. The middle ear is moving as it should.
• Type As or Ad: a peak that is unusually short or unusually tall. These point to a middle ear that is stiffer or looser than normal, and are read together with the audiogram.
• Type B: flat, with no peak. Commonly seen when there is fluid behind the eardrum, a frequent finding in children after colds. A flat tracing with a large ear canal volume can mean a hole in the eardrum, or a grommet that is open.
• Type C: a peak shifted to the left, towards negative pressure. The tube that connects the middle ear to the back of the nose (the Eustachian tube) is not equalising pressure well, as often happens with a cold or allergies.

What to ask your ENT doctor

• Is my hearing loss conductive, sensorineural or mixed, and in which ear?
• What is the grade in each ear, and which pitches are most affected?
• Is this something that can be treated, or something to manage?
• Would a hearing aid help me, and in which ear?
• When should I repeat the test, and should I bring this report next time?

That last question matters more than it sounds. Hearing is followed over years, and a new audiogram means most when it sits beside the previous ones. Keep the paper, or better, keep a copy somewhere you will still have it in three years. A health record on your phone, such as your 92health record, lets you carry every report to the next clinic and share it only when you choose.

When not to wait

See an ENT doctor within a day or two, not at your next routine visit, if you have:

• Sudden hearing loss in one ear, over a few hours or a day or two. Treatment works best when it starts early.
• Hearing loss with dizziness or a spinning sensation.
• Ear pain with discharge and fever.
• Ringing in one ear only that has not gone away.

Hearing loss that creeps up over years is common and usually manageable. Hearing loss that arrives overnight is different, and it is worth a phone call the same day.