# decibel adjusted (dBa)

In Decibel Adjusted (dBa), the absolute noise

power is evaluated. The noise power denotes the ratio between the disturbing effect of the noise frequency or noise band and a noise power weighting level and refers to a noise power of 3.16 picowatts (pW), which corresponds to a value of -85 dBm

and a dBa value of 0. A 1 kHz tone with a sinusoidal power of 1 mW corresponds to +85 dBa. If the same power is distributed as white noise between 300 Hz and 3.3 kHz over a bandwidth of 3 kHz, the dBa value is +82 dBa due to the frequency weighting.