ssh, I think it would be a great idea to follow the instructions and then report back to us what your readings are on the db meter. Also, I doubt any safe levels have been determined, since these things are usually measured and defined by scientists, who don't believe we can hear those tones.
********* UPDATE *********
Of course, I proved myself wrong shortly after writing this. OSHA has done some work on this: http://www.osha.gov/dts/osta/otm/noise/h...onics.html
At 20KHz, the 8hr time-weighted average is 92db, which means that over eight hours, you should have an average db of less than this value. Considering that a normal conversation occurs around 65db, my unprofessional, uneducated, and generally ignorant recommendation is to keep the levels down around that level.
********* UPDATE *********
Of course, I proved myself wrong shortly after writing this. OSHA has done some work on this: http://www.osha.gov/dts/osta/otm/noise/h...onics.html
At 20KHz, the 8hr time-weighted average is 92db, which means that over eight hours, you should have an average db of less than this value. Considering that a normal conversation occurs around 65db, my unprofessional, uneducated, and generally ignorant recommendation is to keep the levels down around that level.
Fear is a liar.
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -- Ernest Hemingway
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -- Ernest Hemingway
