Active headset

DETAILED DESCRIPTION It is an object of the invention to provide an active headset that can cancel external noise in both the higher and lower frequency ranges.
It is another object of the invention to provide an active headset that reduces the subjective pressure within the ears felt by a user.
Therefore, according to the present invention, there is provided an active headset incorporating means for reducing the amount of external noise reaching the ear by generation of a noise cancellation signal extending over a given frequency range, wherein means are provided for use by the user for adjustment of gain at the peak amplitude of the noise cancellation spectrum substantially without reducing the breadth of the given frequency range over which noise reduction is effective.
In a preferred arrangement, the gain of the noise cancellation signal is determined by a bridge amplifier circuit in which the summation node is provided within a resistive/capacitive coupling providing feedback to the feedback input of the operational amplifier in the non-inverting part of the bridge amplifier circuit, and the peak amplitude of the noise cancellation signal is adjustable by means of a variable component in the said resistive/capacitive coupling providing feedback, such as a variable resistance or switchable capacitor.