We put this question to Mairead McSweeney:

Mairead -   Yes, so just as he thinks in Spanish and I think in English, so if you're a native user of British Sign Language, you would think in British Sign Language.  So then the question really is, well, what’s the nature of that thought?  What’s it like?  And so, it can be visual or it could be manual, so motoric, and so we can use different methods in the lab to try and get at that question by using different interference techniques.  And so, it seems to be a bit of both.  There seems to be more weight towards a motor representation that people use in their minds and their thinking in sign language.

Chris -   So they would literally see themselves doing the thing rather than think it through talking to themselves doing it like I might for example.

Mairead -   Well, no.  That would be a visual representation but there’s more weight towards the motoric representation would be more like feeling themselves do it.  It’s just like you feel you hear yourself speak, if you like.  A motor representation of the movement would be the type of representation that they might be bringing up when thinking.

Diana -   So it’s just like imagining eating chocolate in my head.  I can feel the sensations.

Mairead -   Yes, exactly!

We put this question to Karen Steel:

Karen: -   Cochlear implants are usually used for people who have very severe or profound hearing impairment where a hearing aid isn’t very much use to you because you don't have enough hearing left.  Whereas hearing aids are used for a different group of people, a much larger population of people who have mild or a moderate hearing impairment where amplifying what they can hear is of benefit to them.  Basically, that’s what a hearing aid does - It amplifies the sound.

Chris -   Because the cochlear implant (invented in Australia a little while back) is a series of electrodes that directly stimulates the nerves that connect the cochlea to the brain, whereas the hearing aid is relying on putting bigger vibrations in to the ear, to make the hair cells vibrate a bit more.

Karen -   That’s right.  The hearing aid doesn’t do anything biologically to your inner ear and your sensory hair cells are still there and doing the best they can. But the cochlear implant is actually placed inside your ear, so it involves surgery and it’s quite likely to damage the natural hearing ability that you might have because it directly stimulates the nerve endings.

We put this question to Karen Steel:

Well, tinnitus is a ringing or noises that you can perceive.  Sometimes it sounds like it’s really like coming from outside.  Sometimes it sounds as if it’s coming from inside your head.  It’s a sign that either the sensory hair cells or something in your neurons is activating at abnormal times when there isn’t a sensory input.  That can happen because there’s something going wrong with the neuron or something going wrong with the hair cell and that can be an early sign of damage.  And so, if you come away from a loud concert and you found your ears are ringing, you’ve got the first signs of damage and you really shouldn’t do it.  So, why it’s brought on by low levels of background noise?  I don't think anybody really has an answer to that and every person’s tinnitus is very different, so there’s no general answer to that.

Chris - The only, and the best, explanation I've heard of this is that the frequency distribution that’s emitted by the nails going down the chalkboard is very reminiscent, at very high frequencies, of distress sounds produced by other animals.  This plugs in to the primeval response in all of us of an animal in distress.  For this reason, we experience this sound with an “Ouch!  I don't like it!  I have to wake up and take notice!” reaction.