News · Longevity & Aging
Two hearing aids beat one in the first trial to test it, by a margin the authors won't call meaningful
Fitting both ears is standard practice and has never been tested properly. Randomizing 275 older adults found the two-aid group ahead, and the researchers are careful about how far ahead.
- People fitted with two hearing aids reported more benefit than those fitted with one.
- Both groups improved, and by an amount that mattered to them individually.
- The gap between one aid and two was small enough that the authors would not call it meaningful.
- Standard practice has been to fit both ears without this having been tested.
- 275 adults averaging 71, assigned to one aid or two at random.
Age-related hearing loss arrives in both ears at roughly the same rate, so the standard response is to fit both ears. Two ears, two aids. It is what audiologists do and it roughly doubles the bill.
The reasoning behind it is sound. Human hearing uses the tiny differences between what each ear receives to work out where a sound came from and to pull one voice out of a crowded room, and a single aid cannot restore that.
What was missing was a trial. Writing in JAMA Otolaryngology-Head & Neck Surgery, researchers note that data demonstrating the effectiveness of unilateral or bilateral fitting as the standard treatment are lacking, and previously the practice had settled without that evidence. So they randomized 275 participants to one aid or two.
What came back
Both groups did better. That is the first result and it should not be lost behind the comparison, because it establishes that fitting a hearing aid to an older adult with this pattern of loss delivers benefit people notice.
The two-aid group did better still. Mean benefit was 19.74 against 14.41 on the questionnaire, a difference of a little over five points in favor of fitting both ears, with a range that stayed clear of zero.
Then the sentence that makes this worth reading carefully. While statistically detectable, it is not clear whether this reaches the threshold for clinical meaningfulness.
Why the authors held back
A difference can be real and still be too small for the person experiencing it to care about. Researchers set a threshold in advance for how much change on a scale a patient would actually notice, and a result below it is a result that exists in the data and not in anyone’s life.
Here the authors could not say which side of that line the five points fell on. That is an unusually honest place to leave a finding, particularly one that confirms what everybody already does.
The distinction matters commercially. A hearing aid is a small electronic device that you wear in or behind your ear, and a pair often costs several thousand dollars with no insurance contribution. If the second one adds a little, that is information a person budgeting for this deserves.
What a self-reported score does and does not catch
The measure was the Abbreviated Profile of Hearing Aid Benefit, which asks people to rate their own difficulty in ordinary listening situations. That is the right kind of outcome, because the question is whether a device improves someone’s life rather than whether it improves a laboratory measurement.
It may also be the wrong instrument for the specific advantage two ears provide. Knowing which direction a car is coming from, or following one person at a dinner table with four conversations running, are the situations where binaural hearing earns its keep, and a general benefit questionnaire spreads its questions across many circumstances.
If the second aid helps mainly in a narrow set of hard situations, a broad score would dilute it.
The size and shape of the trial
275 adults, mean age 71, roughly half women, split evenly between the two arms. That is a decent size for a device trial and small for detecting a modest difference reliably.
Randomization is the part that matters most. Comparing people who chose two aids with people who chose one would compare people with different money, different hearing and different attitudes to treatment. Assigning it removes that in one step, which is exactly why the absence of such a trial until now is surprising.
Where it leaves the decision
Not with an instruction to buy one aid. Everything in this trial says fitting hearing aids to older adults with age-related loss works, and untreated hearing loss carries consequences for communication and social life that go well beyond volume.
What it does is put a number on the second aid for the first time, and the number is smaller than the confidence with which two have been recommended. The authors say the results inform, but do not yet establish, a standard-of-practice recommendation for bilateral fitting.
For someone who can afford both, nothing here argues against it. For someone choosing between one aid and none because two are out of reach, this is the first evidence that one is a great deal better than nothing.
People also ask
What did the trial find?
Mean benefit scores were 14.41 for the unilateral group (n = 136) and 19.74 for the bilateral group (n = 139), a mean difference of -5.29% (95% CI, -8.79% to -1.80%) favoring bilateral fitting. Both groups showed benefit. The authors note it is not clear whether the difference reaches the threshold for clinical meaningfulness.
Why had nobody tested this before?
Because fitting both ears became standard on the reasoning that hearing works better with two ears, which is true for locating sound and separating speech from noise. Practice settled before the trial was run, which is common for devices rather than drugs.
What is the benefit score measuring?
The Abbreviated Profile of Hearing Aid Benefit, a questionnaire in which people rate their own difficulty in everyday listening situations before and after fitting. It captures what the user notices rather than what an audiometer records.
So is one aid enough?
The trial does not say that. It says both configurations helped, and that the extra help from a second aid was measurable but small enough that the researchers stopped short of calling it clinically meaningful.
Why does the distinction matter?
Because hearing aids are expensive and often not covered by insurance. If the second aid adds a small amount, that is a real finding for someone deciding what they can afford, rather than a reason to skip treatment.
Are there reasons a second aid might matter more than the score shows?
Possibly. Locating where sound comes from and following one voice in a noisy room both depend on two ears, and a general benefit questionnaire may not capture those situations well.
What should someone do with this?
Discuss it with an audiologist, who can weigh the specific pattern of loss in each ear. The trial informs that conversation rather than settling it. This is general information rather than medical advice.