Monday, 5 January 2009

Just a thought...

Recently I have been thinking about illusions, and how important they are to disabled people. For example, I am assured that those who are skilled in lip-reading and signing can actually 'hear' the sound of speech in their minds, by means of 'educated illusion'.

My lip-reading is very poor, so I have to turn on the subtitles when I watch TV. I also turn off the sound, because I find the ever-present 'background' jingles very distracting. How I hate them. Clearly the perpetrators assume that these silly scraps of music can be shuffled backwards and forwards in the ear of the listener, like mental playing cards in a pack.

Certainly an old-fashioned gramophone record is solid enough, and its single groove is spirally shaped. Yet the plain truth is that the music itself only has two dimensions. And you only have to watch the unilateral wobble of the gramophone needle, to understand this.

In the same way, it can be shown that not only live sound, but also the action of the human ear-drum, are two-dimensional. In other words, both actions are composed of nothing more than a frequency of response and a varying degree of energy.

Yet we talk about stereophonic speakers and omni-directional microphones, as if sound was something round and solid, like an invisible dome. Why is this?

I would suggest four possible answers.

First, thanks to the gift of perceptual projection, we have the illusion that the sensations that our ears are experiencing are actually originating somewhere in the distance. We talk about 'the sound of distant gun-fire,' or of 'hearing voices in the garden next door'.

But of course this magical effect does not apply to sound alone. It applies to our other four senses as well. For example, it applies whenever a blind man is feeling his way with a stick. In his mind, it is the tip of the stick which senses the various objects. Whereas in fact it is the sensors in his arm and finger muscles that are responsible.

The second answer is that, with the exception of a few clever animals and machines, most originators of sound transmit the noise all around them. And it is often possible, even for people who have hearing disabilities, to identify each of these sources by turning the head, and cupping the hands around the ears, etc. It's simply a matter of directing the ear to catch the sound waves at the best angle. In other words, as near to ninety degrees as possible.

The third answer, as all lip-readers and ventriloquists know, is psychological. For example, when you see the lips and eyes of a doll moving, the assumption that she is talking to you, is irresistible.

Finally, in real life, different sounds are very often originating in several places at once. Hence the TV/Radio broadcaster's compulsion to load a number of recorded sounds onto a single track, by post-productive editing. Thus, although the end result comes from a single loud-speaker, the idea is to make us feel that we are physically surrounded by a full orchestra of noise-makers.

And it's this crafty little trick that all those who suffer from intrusive TV & Radio jingle should bear in mind, when complaining!


By Richard Tomalin, 'Pipedown' TV/ Radio music sub-campaign.

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