It's definitely far from simple, but I tried to explain it so that it's easy to understand. The difficulty with phase and positioning of the sources (computer and noise-cancelling speaker) will definitely impact the volume of space where you will get 'good' noise cancellation. Within that volume (wh...

Active Noise Cancellation (ANC) isn't too feasible for computers for a number of reasons: 1. Generally the noise in computers is of mid to high frequencies - active noise cancellation works with low frequencies better because of the longer wavelengths. It's easier to have the two waves (primary nois...

Perhaps if some folks were zooming about on motorcycles,drunk,helmetless,listening to thrashmeteal at 110 db,unrestrained by big brothers good intentions,the end result would be fewer fools fouling up the gene pool. We've all done stupid stuff before... Should we ALL be out of the gene pool? Haha.....

My ideas are designed to protect hearing......not to sell i-pods. A non-removable ear-phone setup, would pretty much assure the i-pod would determine the db available to the speakers. And sure, they could be modified by some people......but most would be used as is. This is an area of concern that ...

The problem of these devices contributing to hearing loss has been around for quite a few years, and we're not going to be able to fix it by putting limiting circuits or whatnot to the devices themselves. It's too difficult, and people will circumvent them anyways The only way to reduce the incidenc...

Can't answer your first question but as far as 'accuracy' goes, the 'measurment uncertainty' (the correct term to use!) associated with modern Type 1, or more recently Class 1, sound level meters is probably around +/-1dB (in the hands of a competent user of course!). As I recall, the 2203 meter pr...

When listening to loud sounds for a long time, your threshold increases - your ears get used to the loud noise, and as a protective measure, temporarily decrease your sensitivity to noise. It's called temporary threshold shift (TTS). If the noises/sounds are loud enough, you get what's called a perm...

Gxcad -- He's less than half my age. ;) The age-related falloff in the highs starts way higher than 1.5KHz. More like 10~15KHz. 1.5KHz is generally considered to be mid-band. It's about 2 octaves higher than middle A. Devon has better overall sensitivity. I'm sure I've exposed myself to a lot more ...

Does nobody know?

I tried searching for this info on the site, but it's hard to find... I was just wondering about the calibration of the mics that SPCR is using - do they have up-to-date calibration records? (I know it's quite expensive to keep microphones and associated equipment in current calibration.) Also, how ...