I thought about that but we just dont have earthquakes around here, im stuck looking for a CD.

The Digital Video Essentials contains a Buzz & Rattle Test, 15 Hz to 300 Hz. The only problem is that the test starts at 15Hz then sweeps up to 20Hz and higher to quickly. I would perfer the signal to stay at around 16 for at least a minute, not one second. Regardless, it seems I can 'hear' the signal at 17Hz or 18Hz and I think im hearing it at 16Hz also, its kinda hard to tell.