Are your ears lying? 🙉

In 10 seconds? Hidden hearing loss occurs when a loud enough noise permanently damages your hearing — but though you’ll find it more difficult to pick out voices in noisy environments, you won’t show up as abnormal in standard hearing tests.

Don’t believe it? 8 mouse studies by 3 different research groups since 2009 found permanent damage in the connections between nerves and inner ear hair cells after a short blast of intense sound that doesn’t lead to overall hearing loss. (see the papers)

But mice aren’t the same as humans? Of course, but the most accurate way to measure this sort of damage is still to count healthy nerves in post-mortem samples — so these researchers looked at five donated human ears to verify the mouse results. (read more)

So that’s why this sort of hearing loss is “hidden”?

Yes, you can’t simply see it — Many research groups are now working on methods to detect nerve damage in the ears by measuring electric signals in a non-invasive way. (see the papers)

And you can’t detect it with standard hearing tests — Standard tests can only reveal whether you’re struggling to hear quiet sounds in a quiet environment.

And it’s not uncommon — As early as 1989, a large survey in the UK showed that 26% of adults found it highly difficult to hear speech in noise, of which 84% had apparently normal hearing in the standard tests. (read more)

What’s the opportunity?

For big pharma — Noise-induced hearing loss affects almost ~15% of the US labour force; several potential drugs are now being tested in animal trials.(tweet this)

For the military — US service members recognise the dangers of impaired communication in high noise environments and work with private companies to develop better equipment and speech-in-noise tests. (read more)

For carers of the elderly — There’s a wealth of evidence to show that hearing loss is correlated to mental fatigue, social isolation, and faster progression toward dementia; early detection of hearing problems can drastically improve quality of life. (read more)

For entrepreneurs — Researchers are racing to find a gold standard for measuring hidden hearing loss; can you inject a new perspective? (tweet this)

What non-technical factors could hinder innovations in this field?

Healthcare providers not investing enough to educate about hearing health
Regulatory bodies not planning to review safe sound limits
Not enough consumer interest to protect and monitor their hearing

Wondering what inner ear hairs look like? These are from a frog, courtesy of Dr Bechara Kachar.

(Psst, we digested 20 research papers to save you 560.8 min)

First sent to subscribers of Sparrho Insights on 2nd March 2017

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