Life inside the womb isn’t as blissfully peaceful as you might think. Babies respond to noises from the outside world many months before they are born. Our hearing begins to develop when the cochlea – a bony structure shaped like a snail’s shell – forms in the inner ear. At just over ten weeks the inside of the cochlea (circular cavity, left) is lined with unspecialised cells (stained blue) that will become sensory hair cells. The bundle of nerve cells (blue nuclei, surrounded by green and red stained proteins) will mature to convey messages to the brain by around 18 weeks. Inherited conditions and pregnancy complications – like the mother catching rubella – can stop these cells developing normally, meaning around 1 in 1000 UK babies are born deaf. Understanding inner ear development might help mitigate risks in pregnancy so fewer babies are affected, or improve the effectiveness of remedial treatments like cochlear implants.
Written by Sarah McLusky
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