Method and apparatus for detecting voice activity

A method for detecting audio signal activity comprising the steps of:

• filtering an input signal using a first quadrature high pass filter and a first quadrature low pass filter;
• filtering an output of the high pass filter using a second quadrature high pass filter and a second quadrature low pass filter
• storing an output of the second quadrature high pass filter and an output of the second quadrature low pass filter;
• filtering an output of the first low pass filter using a third quadrature high pass filter and a third quadrature low pass filter;
• storing an output of the third quadrature high pass filter and an output of the third quadrature low pass filter;
• and
• generating a signal activity decision based on an output of at least two of the filters.

An audio signal activity detector comprising:

• a first filter having orthonormal wavelet coefficients, the first filter transforming an input signal to provide a first output signal;
• a second filter having orthonormal wavelet coefficients, the second filter transforming the input signal to provide a second output signal;
• a third filter having orthonormal wavelet coefficients, the third filter transforming the first output signal to provide a third output signal;
• a fourth filter having orthonormal wavelet coefficients, the fourth filter transforming the first output signal to provide a fourth output signal;
• a fifth filter having orthonormal wavelet coefficients, the fifth filter transforming the second output signal to provide a fifth output signal;
• a sixth filter having orthonormal wavelet coefficients, the sixth filter transforming the second output signal to provide a sixth output signal;
• and
• a signal activity decision generator that generates a signal activity decision based on at least one output of the first filter, the second filter, the third filter, the fourth filter, the fifth filter and the sixth filter.