A measure of the degree to which background noise interferes with or MASKs speech. It is obtained by averaging the SOUND PRESSURE LEVELs in the octave frequency bands centred on 500, 1000, 2000 and ...

Example sound levels for different sounds are: whispering \(-20 dB\), background noise at home \(-40 dB\), normal speech \(-60 dB\). The table gives the sound levels of some sources of sound.

We’ve talked about fixing commercial noise cancelling headphones before. If you don’t mind going low-tech, there’s always the easy way out, but those aren’t likely to accommodate speech ...