Invention Grant
- Patent Title: Noise reduction with integrated tonal noise reduction
- Patent Title (中): 降噪功能可降低整体音调噪音
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Application No.: US11961715Application Date: 2007-12-20
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Publication No.: US08489396B2Publication Date: 2013-07-16
- Inventor: Phil A. Hetherington , Xueman Li
- Applicant: Phil A. Hetherington , Xueman Li
- Applicant Address: CA Kanata, Ontario
- Assignee: QNX Software Systems Limited
- Current Assignee: QNX Software Systems Limited
- Current Assignee Address: CA Kanata, Ontario
- Agency: Brinks Hofer Gilson & Lione
- Main IPC: G10L15/20
- IPC: G10L15/20 ; G10L21/02

Abstract:
The system provides a technique for suppressing or eliminating tonal noise in and input signal. The system operates on the input signal at a plurality of frequency bins and uses information generated at a prior bin to assist in calculating values at subsequent bins. The system first identifies peaks in a signal and then determines if the peaks are from tonal effects. This can be done by comparing the estimated background noise of a current bin to the smoothed background noise of the same bin. The smoothed background noise can be calculated using an asymmetric IIR filter. When the ratio of the current background noise estimate to the currently calculated smoothed background noise is far greater than 1, tonal noise is assumed. When tonal noise is found, a number of suppression techniques can be applied to reduce the tonal noise, including gain suppression with fixed floor factor, an adaptive floor factor gain suppression technique, and a random phase technique.
Public/Granted literature
- US20080167870A1 NOISE REDUCTION WITH INTEGRATED TONAL NOISE REDUCTION Public/Granted day:2008-07-10
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