Hi to all,
Some of you might know that the dB scale is a relative scale, it is alway compared to some kind of reference level. If we consider the normal pure tone hearing test, 0 dB would simply mean the average hearing threshold of a healthy population. Since the sensitivity of human hearing greatly varies with frequency I can only imagine that the pure tone audiometry is corrected for that. (A-weighted). Correct?
I used a dB-meter in my car to check the noise levels. Overall the noise levels (at highway speeds) is under 75 (near the driver window) dB. But, the dB meter used A weighted filtering. If I used a flat weighted filter I would read some where near 95 dB. For comparison, if I use the dB meter in our sound insulated room it read about 26 dB(A) or 46 dB(flat). I am either easily below the 80 dB safety limit of 8 hours per day or way above it.
Now for the question...the industry safety limit of 80 dB A-weighted or flat? I guess it is alway A-weighted, but I am not sure.
I also learned that smartphone app dB meters are useless.
Some of you might know that the dB scale is a relative scale, it is alway compared to some kind of reference level. If we consider the normal pure tone hearing test, 0 dB would simply mean the average hearing threshold of a healthy population. Since the sensitivity of human hearing greatly varies with frequency I can only imagine that the pure tone audiometry is corrected for that. (A-weighted). Correct?
I used a dB-meter in my car to check the noise levels. Overall the noise levels (at highway speeds) is under 75 (near the driver window) dB. But, the dB meter used A weighted filtering. If I used a flat weighted filter I would read some where near 95 dB. For comparison, if I use the dB meter in our sound insulated room it read about 26 dB(A) or 46 dB(flat). I am either easily below the 80 dB safety limit of 8 hours per day or way above it.
Now for the question...the industry safety limit of 80 dB A-weighted or flat? I guess it is alway A-weighted, but I am not sure.
I also learned that smartphone app dB meters are useless.