Patent ID: 8515084

Claim:
A passive sound pressure level (SPL) limiter coupled to an audio source, a left earpiece and a right earpiece, wherein the passive SPL limiter limits a left channel audio output signal from the audio source to the left earpiece and limits a right channel audio output signal from the audio source to the right earpiece, the passive SPL limiter comprising: a control circuit electrically connected to the audio source and receiving said left channel audio output signal from the audio source and said right channel audio output signal from the audio source, wherein said control circuit outputs a control signal via a control circuit output; a balancing circuit electrically connected to said control circuit, said balancing circuit receiving said control signal from said control circuit via said control circuit output, wherein said balancing circuit outputs a left channel control signal and a right channel control signal; a left channel limiting circuit electrically connected to said balancing circuit and configured to receive said left channel control signal from said balancing circuit, said left channel limiting circuit comprised of a first pair of FETs, wherein said left channel limiting circuit reduces said left channel audio output signal from the audio source to the left earpiece in proportion to said left channel control signal; and a right channel limiting circuit electrically connected to said balancing circuit and configured to receive said right channel control signal from said balancing circuit, said right channel limiting circuit comprised of a second pair of FETs, wherein said right channel limiting circuit reduces said right channel audio output signal from the audio source to the right earpiece in proportion to said right channel control signal.