Prosecution Insights
Last updated: April 19, 2026
Application No. 18/443,028

ECHO REMOVAL AND SPEECH ENHANCEMENT

Non-Final OA §103§112
Filed
Feb 15, 2024
Examiner
ELAHEE, MD S
Art Unit
2694
Tech Center
2600 — Communications
Assignee
Google LLC
OA Round
1 (Non-Final)
79%
Grant Probability
Favorable
1-2
OA Rounds
3y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
655 granted / 827 resolved
+17.2% vs TC avg
Strong +28% interview lift
Without
With
+27.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
28 currently pending
Career history
855
Total Applications
across all art units

Statute-Specific Performance

§101
6.2%
-33.8% vs TC avg
§103
50.4%
+10.4% vs TC avg
§102
20.0%
-20.0% vs TC avg
§112
8.9%
-31.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 827 resolved cases

Office Action

§103 §112
Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . DETAILED ACTION Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (B) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 11-18 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention. Claim 11 recites the phrase “the microphone signal” in line 8 and the phrase “the speaker signal” in lines 8-9 are indefinite. There are two different “a microphone signal” and two different “a speaker signal” in the claims 1 and 11. It is not clear which one is being referred by each of the phrases. Since claims 12-18 are dependent claims, these claims are also rejected. Claim 13 recites the phrase “the speaker response relationship” in line 2 is indefinite. There are two different “a speaker response relationship” in the claims 1 and 11. It is not clear which one is being referred by the phrase. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1-3, 19, 20 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over WANG et al. (Foreign Pub. No. TWI682672 B) in view of Denton (US Pub. No. 2021/0157544). Regarding claims 1 and 25, with respect to Figures 1-2, WANG teaches a non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by a processor (page 4, paragraph 6), are configured to cause the processor to: receive a microphone signal from a microphone (page 2, first and second paragraphs under “Background-Art”); receive a speaker signal from a speaker associated with the microphone (fig.1; page 2, first and second paragraphs under “Background-Art”); generate a speaker response relationship based on the microphone signal and the speaker signal (fig.1; page 2, first and second paragraphs under “Background-Art”); and generate an enhanced audio signal by modifying an echo associated with the microphone signal using an echo recognition and cancellation system [i.e., model] and the transfer function [i.e., speaker response relationship] (fig.1; page 2, first, second and third paragraphs under “Background-Art”). However, WANG does not specifically teach the model being configured to differentiate between a first sound pattern and a second sound pattern. Denton teaches the smart glasses [i.e., model] being configured to differentiate between a first sound pattern and a second sound pattern (paragraphs 0021, 0162). Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify WANG to incorporate the feature of the model being configured to differentiate between a first sound pattern and a second sound pattern in WANG’s invention as taught by Denton. The motivation for the modification is to do so in order to mitigate potentially harmful sounds and/or warn users accordingly. Regarding claim 2, WANG teaches wherein the instructions are further configured to cause the processor to output the enhanced audio signal representing the microphone signal (page 2, first paragraph under “Background-Art”; “By eliminating audio echo and, in some cases, electronic echo, noise is reduced to improve the quality of the audio detected by these microphone” and second paragraph under “Background-Art”). Regarding claims 3 and 20, WANG teaches wherein the speaker response relationship is a loudspeaker-to-device-microphone transfer function (page 2, third and fourth paragraphs under “Background-Art”). Claim 19 is rejected for the same reasons as discussed above with respect to claim 1. Furthermore, WANG teaches mobile phone. However, WANG does not specifically teach a wearable device including a processor. Denton teaches a wearable device including a processor (abstract; paragraphs 0002, 0157, 0158). Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify WANG to incorporate a wearable device including a processor in WANG’s invention as taught by Denton. The motivation for the modification is to do so in order to detect a possibly harmful amount of sound impinging on the wearer's ears, notify a user about it conveniently. Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over WANG et al. (Foreign Pub. No. TW I682672 B) in view of Denton (US Pub. No. 2021/0157544) further in view of CHANG et al. (U.S. Pub. No. 2022/0199095). Regarding claim 10, WANG does not specifically teach that the model is a machine learning model, and the machine learning model is trained to beamform and suppress echoes associated with speaker signals and suppress external noise. Denton teaches that the model is a machine learning model (paragraph 0144). Whereas CHANG teaches that the machine learning model is trained to beamform and suppress echoes associated with speaker signals and suppress external noise (paragraphs 0021, 0045, 0046). Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify WANG in view of Denton to incorporate the model being a machine learning model, and the machine learning model being trained to beamform and suppress echoes associated with speaker signals and suppress external noise in WANG’s invention as taught by Denton and CHANG. The motivation for the modification is to do so in order to efficiently remove noise and background noise. Allowable Subject Matter Claims 4-9 and 21-24 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Claims 11-18 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims after overcoming the rejection under 35 U.S.C. 112(b). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to MD S ELAHEE whose telephone number is (571)272-7536. The examiner can normally be reached on Monday thru Friday; 8:30AM to 5:00PM EST. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, FAN TSANG can be reached on 571-272-7547. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). /MD S ELAHEE/ MD SHAFIUL ALAM ELAHEE Primary Examiner, Art Unit 2694 February 8, 2026
Read full office action

Prosecution Timeline

Feb 15, 2024
Application Filed
Nov 13, 2025
Examiner Interview (Telephonic)
Nov 15, 2025
Examiner Interview Summary
Feb 04, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
79%
Grant Probability
99%
With Interview (+27.8%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 827 resolved cases by this examiner. Grant probability derived from career allow rate.

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