Band pass and notch filters for echo reduction with less phase distortion
AssigneeAcoustic Technologies, Inc.
InventorsKendall G. Moore, Samuel L. Thomasson
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Abstract
A complementary comb filter includes a plurality of band pass filters and a plurality of notch filters, wherein the notch filters have the same center frequencies as the band pass filters or the same center frequencies as the dead bands defined by the band pass filters. Phase distortion by the notch filters occurs primarily in the notch, thereby eliminating distortion of the signal.
Claims14
In an audio processing circuit utilizing a complementary comb filter including a plurality of band pass filters, the improvement comprising:
- a plurality of notch filters having the same center frequencies as the band pass filters.
In an audio processing circuit utilizing a complementary comb filter including a plurality of band pass filters, the improvement comprising:
- a plurality of notch filters having the same center frequencies as dead bands defined by the band pass filters.
A method for processing an audio signal, said method comprising the steps of:
- dividing the signal into a plurality of bands;
- passing the signal from each band through a pair of notch filters having the combined frequency response of a band pass filter.
In a speaker phone having a speaker and a microphone coupled to a complementary comb filter that includes a plurality of band pass filters for minimizing coupling between said speaker and said microphone, the improvement comprising:
- a plurality of notch filters having the same center frequencies as the band pass filters.
Dependencies are inferred from the claim text.