US 6,553,272 B1 · Method and apparatus for audio signal channel muting

Abstract

An audio interface is coupled to received a music signal and a microphone signal. The music signal and a volume control signal are combined in a multiplier to produce a volume adjusted music signal. In response to an input signal from a user, the volume control signal is gradually changed in predetermined increment levels. Thus, the multiplier gradually changes the audible volume in these predetermined increment levels. The resulting music and microphone signal are stored in corresponding partitions of a single memory, and thereafter provided to a mixing circuit. The mixing circuit combines signal samples read from the memory to produce four output signals each containing first and second channel samples. The resultant 8 channel samples are gated in a formatter with respective channel mute signals which, when asserted, effectively mute their corresponding channel sample.

Claims10

Dependent claims

An audio interface circuit for muting a digital audio signal having first and second channels time-multiplexed using a sample clock, said interface comprising:

a multiplexer having a first input terminal coupled to receive a first channel mute signal corresponding to said first channel, a second input terminal coupled to receive a second channel mute signal corresponding to said second channel, a control terminal coupled to receive said sample clock, and an output terminal;
and
an AND gate having a first input terminal coupled to receive said first and second channels of said digital audio signal, a second input terminal coupled to said output terminal of said multiplexer, and an output terminal, wherein said AND gate provides at said output terminal either said first channel or a zero value signal in response to said first channel mute signal when said sample clock is in a first logic state, and provides at said output terminal either said second channel or said zero value signal in response to said second channel mute signal when said sample clock is in a second logic state.

Dependencies are inferred from the claim text.

Method and apparatus for audio signal channel muting

Life of this patent

Method and apparatus for audio signal channel muting

Life of this patent

Abstract

Claims10