Is hearing believing?


Did anyone else see last night’s Horizon: Is Seeing Believing on BBC2? It could equally well have been called "Is Hearing Believing", or any or all our senses for that matter (magnetic fields anyone?). It was fascinating.

The theory of "crossover" and "plasticity" between the senses - the idea that to some extent we can all "hear" light and "see" sound - was particularly intriguing, and seemed to be backed up by experimental evidence.

Equally intriguing was the theory that the "input" from our eyes and ears comprises only some 20% of the data used by the "seeing" and "hearing" parts of the brain to interpret what it is we think we are looking at or listening to. (I hope I’ve got that bit right!).

The remaining 80% or so is derived by interpolation and extrapolation using a mixture of inherited and learned information already stored in the brain to fill in the gaps and derive an image (analogous to digital algorithms?). Again there was experimental evidence which appeared to back this up.

I was left wondering about the relevance of all this to Hi-Fi. Is it all an illusion? How can we ever hope to agree about what it is we hear? Can we be truly objective? Even double-blind listening tests would seem to be fraught with problems!"