Walking, Hiking and Backpacking around the Lake District. Bargeing around the country in canal boats. Supping ale in canalside beer gardens. Plodding 10 miles to the pub in torrential rain.
Here I have built numerous items of precision electronic instrumentation and test rigs for the commercial acoustic testing of carpets, walls, double glazing, sound-proof doors, absorbent ceilings, acoustic diffusers and hearing defenders. These are all built to meticulous British and Australian Standards with the utmost in quality and precision.
The hearing defender test rig (or audiometer) comprises four pseudo-random quasi-stochastic quantum fluctuators or pink noise generators (pink conformity within 0.05dB over 10Hz to 20kHz). The pink noise is filtered by four sets of 8-pole one-third octave filters, then enters a quadrophonic 2dB step attenuator covering a 40dB range before being amplified by four differential power amplifiers. Four differential power attenuators of 10dB steps covering an 80dB range control the loudness before the signal drives four loudspeakers arranged tetrahedrally within an anechoic chamber where the subject sits centrally, wearing the hearing defenders! These are all built to pass two (almost conflicting) but exacting standards: The British and Australian Standards for audiometric instrumentation, which requires meeting a dynamic range exceeding 140dB, amongst many other demanding specifications. All remotely controlled. Designed, built and tested by the author to last a lifetime. Ultra-high reliability, it is still being used daily after twelve years. A unique piece of precision instrumentation; there is no other in the country! Pictures of the apparatus, a little bit worse for 12-years' continuous wear, below. (I wish the operators wouldn't insist on sticking unsightly stickers over everything)
Manual Remote Control Panel
PRNG Pink generators
Third Octave Filters