Patent ID: 8311242

Claim:
A method comprising amplifying a differential signal produced by a microphone or an audio transducer so as to introduce a controllable degree of distortion, said method including steps of: receiving a differential signal from a microphone or an audio transducer, said differential signal comprising two complementary parts; applying the two complementary parts of said differential signal to an inverting input terminal and a non-inverting input terminal of a differential amplifier, said differential amplifier being configured to produce an output signal at an output terminal, and wherein said differential amplifier is provided with a negative feedback path between said output terminal and both said inverting input terminal and said non-inverting input terminal, thereby introducing into said differential signal a feedback signal related to said output signal, thus controlling the gain of said differential amplifier; and providing non-linear circuitry in said negative feedback path that introduce distortion in said feedback signal that is related to the level of said output signal.