The Laser Microphone

Not everything that can be demonstrated can be turned into a product.  And not every idea for a product should be turned into a product.  Still, everything we use today had an origin, and famous thinkers once declared such developments as the telephone, television, computer, and photocopier near useless or worse.

Thus it was that I found myself today at the Audio Engineering Society exhibits, bending down in front of a transparent tube and singing a scale at the top of my cough-addled lungs.  Below the tube a heater turned a small quantity of oil into a form of smoke, and above it a fan drew the smoke through.  A short distance below the fan, a beam of laser light passed through the tube into a photoreceptor, which detected any effects on the smoke stream caused by my singing — and the noise of the exhibition — as well as any stray light.

The result, when played back, sounded perhaps not quite as good as Edison’s early recording of “Mary Had a Little Lamb.”  But the “Laser Accurate” microphone from Schwartz Engineering & Design of Fair Oaks, California, did pick up my voice using a beam of light.  I admit to some excitement.