Prior art — US Patent 10783899

Analysis of Prior Art Cited in US Patent 10,783,899

Below is an analysis of the prior art cited by the applicant and the examiner during the prosecution of US Patent 10,783,899. This analysis assesses the relevance of each citation to the independent claims (1, 15, and 23) of the patent.

I. U.S. Patent Documents

1. US Patent 9,245,524 B2

Full Citation: Schmidt et al., "Method and a device for reducing noise in a signal," issued January 26, 2016. (Filed: January 13, 2012).
Brief Description: This patent discloses a method for reducing noise in a signal by generating a spectral weighting factor based on a signal-to-noise ratio. It focuses on attenuating noise components while preserving the desired signal.
Potential Anticipation: This reference is relevant as it describes spectral weighting for noise reduction. However, it does not appear to explicitly disclose the use of a "soft speech detector" that outputs a likelihood of speech presence, nor the specific concept of a "dynamic noise overestimation factor" that is modulated based on this likelihood to control the aggressiveness of noise suppression, a key element of claims 1, 15, and 23 of US 10,783,899.

2. US Patent 9,123,336 B2

Full Citation: Theuer, "System for suppressing microphone noise and method for operating the same," issued September 1, 2015. (Filed: April 30, 2013).
Brief Description: This patent describes a system for suppressing microphone noise by using a control unit to adjust a noise suppression filter. The adjustment is based on an analysis of the microphone signal to determine the presence of speech.
Potential Anticipation: This reference teaches adjusting noise suppression based on speech detection. However, it does not detail a "soft" detection mechanism providing a probability of speech. Furthermore, the claims of US 10,783,899 specify a "dynamic noise overestimation factor" linked to this probability, which is a more specific implementation than what is broadly described in this prior art.

3. US Patent 8,892,429 B2

Full Citation: Klippel, "Device and method for influencing a useful signal," issued November 18, 2014. (Filed: April 21, 2008).
Brief Description: This patent discloses a method for improving a useful signal by adapting a filter based on the signal properties. It involves estimating the noise and adjusting the filter to suppress it.
Potential Anticipation: While this patent deals with adaptive filtering for noise suppression, it does not seem to describe the core novelty of US 10,783,899, namely the use of a "soft speech detector" to generate a likelihood of speech and the subsequent use of a "dynamic noise overestimation factor" to control the level of noise suppression.

4. US Patent 8,682,662 B2

Full Citation: Tashev, "Noise suppression with low speech distortion," issued March 25, 2014. (Filed: June 23, 2010).
Brief Description: This patent focuses on a noise suppression system that aims to minimize speech distortion. It uses a voice activity detector to distinguish between speech and noise and adjusts the suppression level accordingly.
Potential Anticipation: This reference is relevant as it discusses adjusting noise suppression based on voice activity. However, the claims of US 10,783,899 are more specific, requiring a "soft speech detector" that provides a likelihood of speech, and a "dynamic noise overestimation factor" controlled by this likelihood. This prior art does not appear to disclose this specific combination of features.

5. US Patent 8,116,781 B2

Full Citation: Choi et al., "Apparatus and method for reducing noise in a mobile communication terminal," issued February 14, 2012. (Filed: January 14, 2009).
Brief Description: This invention relates to reducing background noise in a mobile device by estimating the noise level and applying a suppression algorithm.
Potential Anticipation: This is a general reference for noise reduction in mobile devices. It does not appear to disclose the specific inventive concepts of US 10,783,899, such as the "soft speech detector" and the "dynamic noise overestimation factor" that varies with the likelihood of speech.

6. US Patent 7,558,729 B2

Full Citation: Jaber, "Method of and apparatus for reducing background acoustic noise," issued July 7, 2009. (Filed: November 2, 2005).
Brief Description: This patent describes a method for reducing background noise by analyzing the spectral characteristics of an input signal to differentiate between speech and noise.
Potential Anticipation: This reference is broadly relevant. However, it does not appear to teach the specific implementation of a "soft speech detector" providing a probabilistic output that controls a "dynamic noise overestimation factor" as claimed in US 10,783,899.

7. US Patent 7,487,087 B2

Full Citation: Avendano et al., "System and method for modifying a signal based on a voice activity detection," issued February 3, 2009. (Filed: September 29, 2004).
Brief Description: This patent discloses a system that uses a voice activity detector (VAD) to control signal modification, such as noise suppression.
Potential Anticipation: This prior art describes using a VAD to control noise suppression. However, the claims of US 10,783,899 go beyond a simple VAD by specifying a "soft" detector that determines a likelihood of speech and uses this to dynamically adjust a noise overestimation factor.

8. US Patent 7,424,429 B2

Full Citation: Arrowood et al., "Systems and methods for reducing speech recognition errors caused by babble," issued September 9, 2008. (Filed: March 2, 2004).
Brief Description: This patent specifically addresses the problem of "babble" noise in speech recognition. It describes methods to detect and mitigate the effects of interfering speech.
Potential Anticipation: This is a highly relevant reference as it directly addresses "babble" noise. However, its focus appears to be on improving speech recognition rather than the specific noise suppression technique claimed in US 10,783,899, which involves a soft speech detector and a dynamic noise overestimation factor for controlling spectral weighting.

9. US Patent 7,124,083 B2

Full Citation: Jaber, "Method of and apparatus for reducing background acoustic noise," issued October 17, 2006. (Filed: July 19, 2002).
Brief Description: A related patent to US 7,558,729, this also describes a method for reducing background noise by spectrally analyzing the input signal.
Potential Anticipation: Similar to the other Jaber patent, this is generally relevant but does not seem to disclose the specific combination of a "soft speech detector" and a "dynamic noise overestimation factor" as claimed in US 10,783,899.

10. US Patent 6,876,964 B1

Full Citation: Tsurumaru et al., "Noise suppressor and noise suppression method," issued April 5, 2005. (Filed: May 25, 2001).
Brief Description: This patent describes a noise suppressor that adjusts its characteristics based on whether the input signal is determined to be speech or noise.
Potential Anticipation: This is a general reference for adaptive noise suppression. It does not appear to describe the novel aspects of US 10,783,899, particularly the use of a probabilistic speech detection output to control a dynamic noise overestimation factor.

II. U.S. Patent Application Publications

11. US 2015/0287413 A1

Full Citation: Schmidt et al., "Apparatus and Method for Noise Reduction," published October 8, 2015. (Filed: March 27, 2015).
Brief Description: This application describes a noise reduction method that involves estimating a noise signal and adjusting the suppression based on signal characteristics.
Potential Anticipation: This reference is in the same technology area. However, it does not appear to explicitly teach the combination of a soft speech detector providing a likelihood of speech and a dynamic noise overestimation factor controlled by that likelihood.

12. US 2015/0199923 A1

Full Citation: Li et al., "Method and Device for Detecting Voice Activity," published July 16, 2015. (Filed: January 13, 2015).
Brief Description: This application discloses a voice activity detection (VAD) method.
Potential Anticipation: While relevant to the speech detection aspect, this application does not appear to describe the complete system of claims 1, 15, and 23 of US 10,783,899, which includes the dynamic control of a noise overestimation factor based on the VAD output.

13. US 2015/0142416 A1

Full Citation: Boldt et al., "Method and Arrangement for Reducing Noise," published May 21, 2015. (Filed: November 18, 2014).
Brief Description: This document describes a method for reducing noise in an audio signal by using a control signal to adapt a noise reduction filter.
Potential Anticipation: This is a general reference for adaptive noise reduction. It lacks the specific details of a soft speech detector providing a probability of speech that in turn controls a dynamic noise overestimation factor.

14. US 2013/0110488 A1

Full Citation: Abe et al., "Noise Suppression Device, Noise Suppression Method, and Program," published May 2, 2013. (Filed: October 26, 2012).
Brief Description: This application describes a noise suppression device that uses spectral subtraction.
Potential Anticipation: This reference pertains to noise suppression but does not appear to disclose the specific control mechanism involving a soft speech detector and a dynamic noise overestimation factor as claimed in US 10,783,899.

15. US 2010/0286981 A1

Full Citation: Konchitsky et al., "System and Method for Single-Channel Speech Enhancement," published November 11, 2010. (Filed: May 8, 2009).
Brief Description: This application describes a single-channel speech enhancement system that differentiates between speech and noise to apply noise reduction.
Potential Anticipation: This is relevant to the field but does not appear to teach the specific combination of a soft speech detector and a dynamic noise overestimation factor as the control mechanism for the noise suppression.

16. US 2010/0211382 A1

Full Citation: Yamamoto et al., "Noise canceller, portable terminal, and noise cancelling method," published August 19, 2010. (Filed: February 16, 2010).
Brief Description: This publication describes a noise canceller for a portable terminal that adjusts noise cancellation based on the detected environment.
Potential Anticipation: This reference is for noise cancellation in portable devices but does not seem to include the specific details of the control mechanism claimed in US 10,783,899.

17. US 2009/0171661 A1

Full Citation: Akbacak et al., "System and Method for Voice Activity Detection and Speech Enhancement," published July 2, 2009. (Filed: December 31, 2007).
Brief Description: This application describes a system that combines voice activity detection with speech enhancement.
Potential Anticipation: This reference is relevant to both aspects of the invention. However, it does not seem to explicitly disclose the use of a "soft" VAD output to control a "dynamic noise overestimation factor" for adjusting the aggressiveness of the speech enhancement.

18. US 2005/0149320 A1

Full Citation: Cho, "Speech Enhancement System and Method Thereof," published July 7, 2005. (Filed: December 16, 2004).
Brief Description: This application describes a speech enhancement system that uses a noise estimation module and a speech enhancement module.
Potential Anticipation: This is a general reference for speech enhancement and does not appear to describe the novel control mechanism of the noise suppression detailed in claims 1, 15, and 23 of US 10,783,899.

Summary of Prior Art Analysis

The cited prior art establishes a foundation in the field of noise suppression and voice activity detection. Many of the references disclose systems that adjust noise reduction based on whether speech is present. However, none of the cited references appear to fully anticipate the independent claims of US Patent 10,783,899. The key distinguishing features of the patent seem to be the combination of:

A "soft speech detector" that provides a likelihood or probability of speech presence, rather than a simple binary (speech/no-speech) output.
A "dynamic noise overestimation factor" that is directly and dynamically controlled by this likelihood. This factor is increased during likely speech pauses for more aggressive noise suppression and decreased during likely speech activity to protect the speech from distortion.

This specific control mechanism for dynamically modulating the aggressiveness of noise suppression based on a probabilistic measure of speech presence appears to be the novel contribution of US 10,783,899 over the cited prior art. Therefore, the cited references, while relevant to the general field, do not appear to anticipate the specific combination of elements recited in independent claims 1, 15, and 23.