An electronic device includes one or more microphones that generate audio signals and a wind noise detection subsystem. The electronic device may also include a wind noise reduction subsystem. The wind noise detection subsystem applies multiple wind noise detection techniques to the set of audio signals to generate corresponding indications of whether wind noise is present. The wind noise detection subsystem determines whether wind noise is present based on the indications generated by each detection technique and generates an overall indication of whether wind noise is present. The wind noise reduction subsystem applies one or more wind noise reduction techniques to the audio signal if wind noise is detected. The wind noise detection and reduction techniques may work in multiple domains (e.g., the time, spatial, and frequency domains).

In some embodiments, a method, apparatus and computer program for reducing noise from an audio signal captured by a drone (e.g., canceling the noise signature of a drone from the audio signal) using a model of noise emitted by the drone's propulsion system set, where the propulsion system set includes one or more propulsion systems, each of the propulsion systems including an electric motor, and wherein the noise reduction is performed in response to voltage data indicative of instantaneous voltage supplied to each electric motor of the propulsion system set. In some other embodiments, a method, apparatus and computer program for generating a noise model by determining the noise signature of at least one drone based upon a database of noise signals corresponding to at least one propulsion system and canceling the noise signature of the drone in an audio signal based upon the noise model.

Systems, methods, and computer program product embodiments are disclosed for removing any fixed frequency interfering signal from an input signal without introducing artifacts that are not part of the original signal of interest. An embodiment operates by using a virtual buffer with a length that matches a length of one cycle of an interfering signal. The embodiment extracts the interfering signal into the virtual buffer. For a sample in the next cycle of the interfering signal that corresponds to a virtual memory location for the virtual buffer, the embodiment can update one or more physical memory locations of the virtual buffer that are in the vicinity of the virtual memory location. This use of virtual buffer can remove any interfering signal without creating the artifacts associated with conventional notch filters.

An apparatus includes a CPU and a memory storing a program that causes the apparatus to function as the following units. A first amplification unit that amplifies a the sound signal from a first microphone for acquiring an environment sound, a second amplification unit that amplifies a sound signal from a second microphone for acquiring a noise of a noise source in accordance with a amplification amount, a conversion unit that performs Fourier transform on sound signals from the first amplification unit and the second amplification unit, a reduction unit that reduces noise from first sound data using noise data. The amplification amount is set based on at least one of a level of the sound signal from the second amplification unit and a type of the noise source.

A sound processing apparatus includes a first microphone that acquires an environmental sound, a second microphone that acquires noise from a noise source, a first conversion unit that performs Fourier transform on a sound signal from the first microphone to generate first sound data, a second conversion unit that performs Fourier transform on a sound signal from the second microphone to generate second sound data, a first reduction unit that reduces noise from the noise source in the first sound data using noise data, a detection unit detects, based on the second sound data, that short-term noise from the noise source is included in the first sound data, a second reduction unit that controls a magnitude of sound data from the first reduction unit and reduces the short-term noise, and a third conversion unit that performs inverse Fourier transform on sound data from the second reduction unit.

Methods and apparatuses for detecting user speech are described. In one example, a method for detecting user speech includes receiving a microphone output signal corresponding to sound received at a microphone and identifying a spoken vowel sound in the microphone signal. The method further includes outputting an indication of user speech detection responsive to identifying the spoken vowel sound.

An event data recorder as a recording device for vehicles capable of recording clear sound data that may contribute to investigation of a cause of an accident in event recording data, regardless of a sound volume of an audio sound played back in the own vehicle, includes a video data acquisition unit configured to acquire video data including sound data and imaging an area around the own vehicle, a sound volume detection unit configured to detect a sound volume of an audio sound played back in the vehicle, and a recording control unit configured to record video data including data by which a sound volume of an audio sound can be determined and sound data on which an effect of an audio sound is small, when a sound volume of an audio sound detected by the sound volume detection unit is greater than a sound volume.

[Problem] To provide a communication apparatus that makes a subject's voice more audible. [Means for Solution] A communication apparatus 60 has: a microphone 61 for receiving, during rotation of a rotating section 26, sound containing a voice of a subject 5 to be examined and noise caused by the rotation of the rotating section 26; a DSP 623 for executing filter processing for reducing said noise contained in the sound received by the microphone 61, wherein the DSP 623 determines a frequency of the noise caused by the rotation of the rotating section 26 based on a rotational speed vi of the rotating section 26, and sets a filter characteristic F(ti) for the DSP so that a frequency component of the noise contained in the sound is removed; and a speaker 63 for outputting the sound which contains the voice of the subject 5 and from which the frequency component of said noise has been removed.

An adaptive dynamic audio hum extractor eliminates line frequency hum components and associated higher harmonics from an audio signal. An audio signal containing line frequency hum can be processed by providing dynamically controlled notch filters at the fundamental line frequency and additional harmonic multiples of the fundamental frequency. The audio signal is detected to provide dynamic control of the depth of the notch filters. Alternatively, an audio signal containing hum can be processed by dividing the spectrum into at least two frequency bands, an unaltered high band combined with a dynamically processed low band. The adaptive dynamically controlled notch filters vary the depth of the notches in relation to the envelope or time averaged level of the bandwidth limited audio signal. This allows masking of the hum components with higher levels of audio, thereby providing transparency devoid of audio path notches.

The present invention discloses an audio processing circuit, wherein when the audio processing circuit determines that a signal being processed is a small signal, an output stage uses a regulated supply voltage provided by a voltage regulator, and the output stage uses an open-loop structure to reduce noise of an output audio signal; and when the audio processing circuit determines that the signal being processed is a large signal, the output stage directly uses the supply voltage without using the regulated supply voltage, and the output stage uses a closed-loop structure to reduce the total harmonic distortion of the output audio signal. By using the present invention, the audio processing circuit can have a good performance indicator with a small chip area design.