Patent ID: 6882734

Claim:
A vehicle accessory comprising: an accessory housing for attaching to a vehicle; a first transducer carried by said accessory housing and generating a first audio signal; a second transducer carried by said accessory housing and generating a second audio signal; and a microphone interface circuit electrically coupled between said transducers and a remote processing circuit located remote from the vehicle accessory, said microphone interface circuit comprising: a first electrical signal path extending between said first transducer and the remote processing circuit, and a second electrical signal path extending between said second transducer and the remote processing circuit, said second electrical signal path including a phase inverter circuit provided proximate said second transducer for inverting the phase of the second audio signal such that the second audio signal transmitted over the second electrical signal path has an inverted phase relative to the first audio signal transmitted over the first electrical signal path, and such that any line-induced noise present on the first electrical signal path will also be present on the second electrical signal path and will be in-phase with the line-induced noise on the first electrical signal path.