I've been working in a really noisy spot recently - so noisy, that I have been reduced to buying some ear plugs, and giving serious consideration to some expensive noise cancelling headphones.
Being the curious type, I actually want to know how noisy the place is. I want to measure the noise level with a noise meter thingy.
So I did a bit of googling, and found that it would cost me about $US120 to get a meter, so I dropped that idea and invested in another bucket of 80 cent earplugs.
But I did find this.
ELF-Zone / General Purpose EMF Detector for Home, Office & Paranormal Investigations
I guess someone has to make a buck out of it.