Active headset
First Claim
1. An active headset incorporating noise cancellation circuitry for reducing the amount of external noise reaching a user'"'"'s ear by generation of a noise cancellation signal spectrum extending over a given frequency range, comprising:
- an adjustment element that adjusts a noise cancellation gain/frequency response of the noise cancellation circuitry without substantially reducing the breadth of the given frequency range over which noise reduction of external noise reaching the user'"'"'s ear is effective, wherein the adjustment element further comprises;
a bridge amplifier circuit having a resistive-capacitive coupling, the resistive-capacitive coupling having a summation node providing a high frequency shelf for an operational amplifier in a non-inverting amplifier stage of the bridge amplifier circuit.
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Accused Products
Abstract
An active headset providing for reduction of external noise over a given frequency range by means of a microphone which generates an external noise representative signal processed and fed to a loudspeaker to produce an external noise cancellation signal spectrum, wherein a bridge amplifier circuit is interposed between the microphone and the loudspeaker and the gain of the bridge amplifier for peak amplitude of the noise cancellation signal is user adjustable without substantially reducing the breadth of the given frequency range over which noise reduction is effective.
45 Citations
15 Claims
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1. An active headset incorporating noise cancellation circuitry for reducing the amount of external noise reaching a user'"'"'s ear by generation of a noise cancellation signal spectrum extending over a given frequency range, comprising:
an adjustment element that adjusts a noise cancellation gain/frequency response of the noise cancellation circuitry without substantially reducing the breadth of the given frequency range over which noise reduction of external noise reaching the user'"'"'s ear is effective, wherein the adjustment element further comprises; a bridge amplifier circuit having a resistive-capacitive coupling, the resistive-capacitive coupling having a summation node providing a high frequency shelf for an operational amplifier in a non-inverting amplifier stage of the bridge amplifier circuit. - View Dependent Claims (2, 3, 4, 5)
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6. An active headset incorporating noise cancellation circuitry for reducing the amount of external noise reaching a user'"'"'s ear by generation of a noise cancellation signal spectrum extending over a given frequency range, comprising:
an adjustment element that adjusts a noise cancellation gain/frequency response of the noise cancellation circuitry without substantially reducing the breadth of the given frequency range over which noise reduction of external noise reaching the user'"'"'s ear is effective, wherein the adjustment element further comprises; an amplifier having a non-inverting amplifier stage and an inverting amplifier stage; and a resistive-capacitive coupling having a summation node providing a high frequency shelf for the amplifier in the inverting amplifier stage. - View Dependent Claims (7, 8, 9, 10, 13, 15)
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11. An active headset incorporating noise cancellation circuitry for reducing the amount of external noise reaching a user'"'"'s ear by generation of a noise cancellation signal spectrum extending over a given frequency range, comprising:
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an operational amplifier having a non-inverting amplifier stage and an inverting amplifier stage; a resistive-capacitive coupling providing a high frequency shelf for the operational amplifier in the inverting amplifier stage, the resistive-capacitive coupling having a summation node; and a means for adjustment of gain comprising a variable component of the resistive-capacitive coupling. - View Dependent Claims (12, 14)
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Specification