Patent ID: 8340307

Claim:
A passive sound pressure level (SPL) limiter coupled to an earpiece and an audio source, wherein the passive SPL limiter limits an audio signal from the audio source to the earpiece, the passive SPL limiter comprising: a control circuit electrically connected to the audio source and receiving an output signal from the audio source, said control circuit comprising a rectifier circuit, wherein said control circuit outputs a control signal via a control circuit output; and a limiting circuit electrically connected to said control circuit output, said limiting circuit receiving said control signal from said control circuit via said control circuit output, said limiting circuit comprising a transistor, and wherein said limiting circuit reduces power from the audio source to the earpiece in proportion to said control signal in order to limit the audio signal from the audio source to the earpiece, and wherein said transistor limits voltage from the audio source to the earpiece in proportion to said control signal.