Sending loudness rating
The sending loudness rating (SLR) is a measure of the loudness of the transmit audio sent through the microphone of a communication device (for example, a mobile phone) It compares the Sound intensity of the sound waves into the microphone to the resulting audio signal. It is measured in dBV/Pa.
For telephony, the reference sound pressure level is 20 micro-Pascals, with values in dB referenced to that value.
- tsbmail. "P.79 : Calculation of loudness ratings for telephone sets". www.itu.int. Retrieved 2016-12-20.