I can hear, but I can't understand: what is going on

It is the sentence almost everything starts with: “My hearing is perfect, the problem is that people don’t speak clearly.”

Whoever says it is right about the first half. They do hear. They notice the volume, they know they are being spoken to, they can tell whether the voice is a man’s or a woman’s. What they cannot do is reassemble the word.

It is not a quirk and it is not an excuse. It is an exact description of what is happening inside the ear, and there is an explanation for it.

The consonants live up high

A spoken word is made of two kinds of sound.

Vowels are low-pitched, powerful sounds. They carry almost all the energy, which is to say almost all the volume. They are what makes you notice that someone is talking from the next room.

Consonants are high-pitched, weak sounds. S, f, th, sh, k, t, p. They carry very little energy and, in exchange, they carry the information. They are what separates “thin” from “fin”, “sip” from “ship”, “cat” from “pat”.

Age-related hearing loss attacks precisely the high frequencies. The medical literature describes it as the characteristic feature of presbycusis: difficulty perceiving and discriminating high-pitched consonants against lower-pitched vowels, so that other people’s speech sounds mumbled or muffled.

Translated: the full volume of the sentence reaches you and the pieces that make it intelligible are missing. The brain fills in what it can, which is why it works well in a one-to-one conversation in the sitting room and collapses in a restaurant.

Why you do not see it coming

Four reasons, and all of them work against you.

It is gradual. The American national institute on deafness describes it as a loss that happens little by little as we get older. Nobody perceives a 2% change a year.

It is symmetrical. It affects both ears, so there is no good ear to compare with. If only one were failing, you would have spotted it in a week.

The brain compensates. It lip-reads without your knowing, it works things out from context and it accepts sentences it has only half understood. It compensates so well that you do not notice the effort until evening comes and you are exhausted without having done anything.

Everyone around you adapts. The family starts talking louder, repeating, and saying “never mind, it wasn’t important”, and the problem becomes invisible inside the house.

And there is one more reason, which is not physiological. Losing your sight is corrected with a pair of glasses and nobody sees old age in them. Losing your hearing still carries that stigma. It is unfair and it is expensive.

The signs

Read them thinking about the last six months. With three or more, an assessment is worth having.

• You turn the television up more than the rest of the household, and somebody has mentioned it.
• In restaurants and at family meals you lose the thread. It is the earliest sign of all.
• The telephone is hard work, especially with numbers and names.
• You hear men better than women, and children worse still. Their voices are higher-pitched.
• You ask people to repeat several times a day, or you say “sorry?” out of habit to buy yourself a second.
• It seems to you that everybody mumbles.
• You cannot tell where a sound is coming from: the doorbell, the phone, a car approaching.
• You hear a constant ringing or buzzing, especially in silence.
• You get tired of being with people and you have started turning down anything with more than three of them.

That last sign is the one that matters most, and the one least often mentioned. The World Health Organization links unaddressed hearing loss with difficulties in communication, social isolation and loneliness.

The home test that is actually worth something

No test at home replaces an audiogram. But there is one that gives a good indication and needs only one other person.

Ask somebody to stand behind you, about two metres away, and to say single two-syllable words in a normal voice: “table”, “cushion”, “beach”, “market”, “pencil”. Without you seeing their face. Without context. Repeat it with the television on quietly in the background.

If you understand with the face in front of you and fail from behind, it is not that people mumble. It is that you were lip-reading.

The uncomfortable figure: ten years

The guidance from the British institute NICE on hearing loss in adults sums it up like this: the evidence suggests that most people with hearing loss have lived with their symptoms for ten years before being referred for appropriate intervention.

Ten years. It is longer than anyone would take to see a doctor about anything else, and it happens because the loss is slow, because it does not hurt, and because there is no particular day on which you decide the time has come.

Meanwhile, age-related hearing loss is one of the most common things that happens to an older person: according to the American national institute on deafness, roughly one in three people between 65 and 74 has hearing loss, and almost half of those over 75.

Why waiting has a cost

Hearing and understanding are two different capacities, and they are not lost at the same time.

The first to suffer is audibility: there are sounds that no longer arrive. That part is compensated for with amplification.

The second is discrimination: the ability to turn what arrives into words. It depends on the ear and also on the brain, which needs to keep receiving stimulation to stay in practice. An ear that spends years without receiving high frequencies stops being trained to process them.

That is why two people with identical audiograms can get very different results from the same hearing aid, and why an early fitting usually goes better than a late one. It is not a promise of a result. It is the reason audiology insists so much on not letting it drift.

When to see a doctor, not an optician

These situations are not presbycusis and need medical assessment without waiting:

• Sudden hearing loss, over hours or a day. It is an ENT emergency.
• Loss in one ear only, or a clear asymmetry between the two.
• Ear pain, discharge or bleeding.
• Vertigo or unsteadiness accompanying the loss.
• Tinnitus in one ear only, particularly if it pulses.
• Loss after a blow to the head or after an explosion.

In any of those cases, a hearing centre does the right thing by referring you. We observe signs that require medical assessment and tell you where to go.

What a proper hearing assessment is

It is not pressing a button when a beep sounds. A complete assessment includes, as a minimum:

• Otoscopy, to see the canal and the eardrum. A plug of wax on its own produces a noticeable loss and is resolved there and then.
• Pure-tone audiometry, which measures the threshold at each frequency and draws the audiogram. There, literally, you see the high frequencies fall away.
• Speech audiometry, which measures how many words you understand and at what volume. It is the test that answers “I hear but I don’t understand”, and it is the one that often is not done.
• Tympanometry, to assess the middle ear.
• A conversation about your life: whether you drive, whether you eat with a lot of people, whether you speak on the phone to children who live abroad, how much noise you had at work.

Out of that comes an audiogram that is kept on file and against which the next review is compared. That series of audiograms over the years is worth more than any single test.

Before booking an appointment

On this website there is a hearing screening you can do yourself, in your own language and from home. It takes a few minutes, it asks you for no personal details at all, and it tells you whether the next step is worth taking.

It is a screening, not a diagnosis. No test done at home, even with headphones as the test itself asks for, can replace a booth. But it does the one thing that matters at this stage: it stops the argument about whether people mumble and puts a number on the table.

And if the result comes back clean, you now have your baseline for a year from now.