# US 2020/0286501 A1 · Apparatus and a method for signal enhancement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0286501 A1 - Document ID: US20200286501A1 - Status: Published application - Kind: A1 - Application number: 16/847,239 - Filed: 2020-04-13 - Published: 2020-09-10 - Earliest claimed: 2017-10-12 - Applicants: Huawei Technologies Co., Ltd. - Inventors: Wei XIAO; Wenyu JIN - Web page: https://patentgrep.com/patent/US20200286501A1 ## CPC - G10L 21/0208: Noise filtering - G10L 25/84: for discriminating voice from noise - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING ## Abstract A signal enhancer includes an input configured to receive an audio signal. It also includes a processor that is configured to generate at least two different filters based on the audio signal X of a current frame. The processor is also configured to generate at least two filtered signals by applying each of the at least two filters to the audio signal of the current frame respectively. The processor is further configured to generate an enhanced audio signal Y for the current frame by merging the n filtered signals. This improves the robustness of the signal enhancement. ## Claims ### Claim 1 A signal enhancer, the signal enhancer comprising: an input configured to receive an audio signal X; and a processor configured to: generate n different filters based on the audio signal X of a current frame, wherein n≥2; generate n filtered signals by applying each of the n filters to the audio signal X of the current frame, respectively; and generate an enhanced audio signal Y for the current frame by merging the n filtered signals, wherein the processor is configured to: generate the enhanced audio signal as a weighted sum of the n filtered signals, wherein the n weight values are based on a detected probability of speech presence in the audio signal X of the current frame. ### Claim 2 (depends on 1) The signal enhancer of claim 1, wherein the processor is configured to, for each of the n filters: generate a target signal S based on the audio signal X of the current frame; and generate a respective filter, of the n filters, so that a filtered signal Z, of the n filtered signals, obtained by applying the respective filter to the audio signal X of the current frame, approximates the target signal S. ### Claim 3 (depends on 2) The signal enhancer of claim 2, wherein the operation of generating the respective filter comprises adapting the respective filter to the target signal S iteratively in one or more iterations. ### Claim 4 (depends on 3) The signal enhancer of claim 3, wherein the operation of generating the respective filter comprises terminating adapting the respective filter upon determining that a measure of a difference between the filtered signal Z and the target signal S is below a predefined threshold. ### Claim 5 (depends on 1) The signal enhancer of claim 1, wherein the set of n filters comprises a first filter and a second filter, and wherein each of the first filter and the second filter comprises one of the following: a noise-reduction filter, a noise-masking filter, a de-reverberation filter, a linear beam-forming filter, or an echo-cancellation filter. ### Claim 6 (depends on 1) The signal enhancer of claim 1, the signal enhancer comprising a pre-processor configured to: pre-process the audio signal X of the current frame, and use the pre-processed audio signal of the current frame as the audio signal of the current frame in the operation of generating the n filtered signals. ### Claim 7 (depends on 6) The signal enhancer of claim 6, wherein the set of n filters comprises a first filter and a second filter, and wherein each of the first filter, the second filter, and the pre-processor is chosen discriminately from one of the following: a noise-reduction filter, a noise-masking filter, a de-reverberation filter, a linear beam-forming filter, or an echo-cancellation filter. ### Claim 8 (depends on 5) The signal enhancer of claim 5, wherein the noise-reduction filter is configured to perform a noise reduction on an audio signal of a current super frame, the current super frame comprising the current frame. ### Claim 9 (depends on 5) The signal enhancer of claim 5, wherein the noise-masking filter is configured to perform a noise masking operation on a plurality of spectral components of an audio signal of a current super frame, the current super frame comprising the current frame. ### Claim 10 (depends on 9) The signal enhancer of claim 9, wherein the noise masking operation is based on a plurality of estimated noise power components, each noise power component being an estimated noise power of a respective spectral component of the audio signal of the current super frame. ### Claim 11 (depends on 9) The speech enhancer of claim 9, wherein the plurality of spectral components in the audio signal of the current frame corresponds to a windowed frame of the audio signal of the current frame. ### Claim 12 (canceled) ### Claim 13 (depends on 1) The signal enhancer of claim 1, wherein the weighted sum is generated on the basis of n weight values, which are either pre-determined or determined based on the audio signal of the current frame. ### Claim 14 (canceled) ### Claim 15 (depends on 1) The signal enhancer of claim 1, wherein the n weight values are equal to a minimum value between a ratio and 1, and wherein the ratio is a result of the detected probability of speech presence divided by a predefined value. ### Claim 16 (depends on 1) The signal enhancer of claim 1, wherein the signal enhancer is implemented in a voice communication terminal or in an automatic speech recognition system. ### Claim 17 A method for signal enhancement, the method comprising: receiving an audio signal X; generating n filters based on the audio signal X of a current frame, wherein n≥2; generating n filtered signals by applying each of the n filters to the audio signal X of the current frame, respectively; and generating an enhanced audio signal Y for the current frame by merging the n filtered signals. ### Claim 18 A non-transitory machine readable storage medium having stored thereon processor executable instructions implementing a method, the method comprising: receiving an audio signal X; generating n filters based on the audio signal X of a current frame, wherein n≥2; generating n filtered signals by applying each of the n filters to the audio signal X of the current frame respectively; and generating an enhanced audio signal Y for the current frame by merging the n filtered signals wherein the processor is configured to: generate the enhanced audio signal as a weighted sum of the n filtered signals, wherein the n weight values are based on a detected probability of speech presence in the audio signal X of the current frame.