I've done shutter speed test using sound recorded with a microphone connected to a computer. It's pretty good up to 1/60s or so. Better option is this product: http://www.ebay.com/itm/Camera-shutt...item230a1554f6

This actually uses a photodiode to detect the increase/decrease in the amount of light, THEN converts that into sound waves sent to the computer. With this I can measure up to 1/250s reliably, and pretty good at 1/500s. The specs say it can do 1/1000s, which I'm finding hard to do. Regardless, you really can't beat the price