Patent ID: 8315408

Claim:
A method of operating an acoustic device comprising: a digital signal processor (DSP) for driving a digital audio channel with a digital output signal; and two digital audio channels, each comprising: a digital-to-analog converter adapted to convert the digital output signal received from the DSP into a corresponding analog signal; and an amplifier adapted to convert said analog signal into an amplified signal for driving an audio transducer, the method comprising the steps of: driving a first of the two audio channels with the digital output signal; configuring the DSP to change the digital output signal so that the amplified signal produced by the amplifier in the first audio channel gradually ramps from a working DC value of said amplifier to a reference DC value; switching the digital output signal from being applied to said first audio channel to being applied to a second of the two audio channels; further configuring the DSP to change the digital output signal so that the amplified signal produced by the amplifier in the second audio channel gradually ramps from the reference DC value to a working DC value of said amplifier; and driving said second audio channel with the digital output signal.