And Now For The Scientific Bit…..

So here’s what I make of it.

Medicine, to me, is usually something akin to witchcraft (but then so is flying and anything else I don’t really understand). I do have a degree in Biology, so my understanding of some of the terms and principles is better than the average man on the street, but not by much.

Hearing, in particular, is a process that seems to baffle even the experts. Sound waves are converted into motion by the various small membranes, bones and hairs in the different sections of the ear and it is this motion that can be turned into a nervous impulse and sent to the brain. The brain then learns this as sound which brings us the delights that are the birds singing, the waves crashing and the Foo Fighters or the horrors of a grade 1 violin player and Take That.

As with any part of the body, if one part of a pathway breaks, the whole thing collapses. It doesn’t really matter where on the pathway the problem is. It’s like the signals at Piccadilly Circus tube station breaking down. All the other stations and lines on the underground may be working, but the trains can’t travel past Piccadilly Circus. In my slightly addled brain, this is how I have come to learn about deafness. If something in the ear or associated nervous system is broken or absent, the journey of sound breaks down and we don’t hear.

Auditory Neuropathy (AN) or Auditory Neuropathy/Auditory Dyysynchrony (AN/AD) or Auditory Neuropathy Spectrum Disorder (ANSD) or whatever the hell it is called is something of an enigma in hearing loss terms. Strictly speaking, the majority of children with this type of hearing loss are not deaf at all – they just can’t hear (do you see what I did there? Now you understand why I’m confused)

ANSD is more a description of a group of symptoms than it is a name for a particular condition in its own right. It seems to refer to the case where the ear is picking up sound, but for some reason, this sound is not transmitted as it should be to the brain. This could be for any number of reasons: A problem with the auditory nerves or associated synaptic junctions or, possibly, some problem with the synchronisation of the hair movements in the inner ear.

As a result, children hear some or all of their sound as distortion, making it difficult or impossible to discriminate speech. The best explanation of what the experts think it might be like is a ‘badly tuned radio’. You can hear some speech in there, but the white noise means it is very difficult to make it out properly. Thus, some children can get by without any intervention, but will suffer in a noisy background and others, like Alice, seem to hear no speech at all and, for at least a part of the time, act as if (or may as well be) profoundly deaf.

Little Alice’s nerves all seem to be working ok so the problem is somewhere else. Save for chopping her up and taking a look, there is no way of telling. The best guess is that she has an inner hair cell dyssynchrony meaning the signal to her brain is scrambled (hence the absent ABR). As we have now learnt, an absent ABR does not mean there is no signal going to the brain; it only detects a strong and coordinated signal. Alice could be hearing all sound as Pink Floyd tunes for all we know.

So there you have it. This is why Alice’s ears don’t work – witchcraft and guesswork. We are both mathematicians at heart. We understand cold, hard facts. Guessing games, theories and best estimates don’t sit very comfortably.

I just wish somebody could tell us what was really wrong.

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