Abstract: A method includes: generating a first and second shift signal by using a phase of a sound signal regarding an M-channel or a S-channel, the sound signal of the M-channel and the sound signal of the S-channel being obtained by using a mid-side microphone, the sound signal of the S-channel including a positive channel and a negative channel, the first shift signal being configured to reduce a phase difference caused by a difference between a sound arrival distance to the M-channel and a sound arrival distance to the positive channel of the S-channel, the second shift signal being configured to reduce a phase difference caused by a difference between the sound arrival distance to the M-channel and a sound arrival distance to the negative channel of the S-channel; and approximately converting the first or second shift signal into an L-channel signal and an R-channel signal of an XY-microphone.

Abstract: A non-transitory computer-readable storage medium storing a program that causes a processor included in a computer mounted on a sound source direction estimation device to execute a process, the process includes calculating a sound pressure difference between a first voice data acquired from a first microphone and a second voice data acquired from a second microphone and estimating a sound source direction of the first voice data and the second voice data based on the sound pressure difference, outputting an instruction to execute a voice recognition on the first voice data or the second voice data in a language corresponding to the estimated sound source direction, and controlling a reference for estimating a sound source direction based on the sound pressure difference, based on a time length of the voice data used for the voice recognition based on the instruction and a voice recognition time length.

Abstract: An utterance detection apparatus includes a processor configured to: detect an utterance start based on a first sound pressure based on first audio data acquired from a first microphone and a second sound pressure based on second audio data acquired from a second microphone; suppress an utterance start direction sound pressure when the utterance start direction sound pressure, which is one of the first sound pressure and the second sound pressure being larger at a time point of detecting the utterance start, falls below a non-utterance start direction sound pressure, which is the other one of the first sound pressure and the second sound pressure being smaller at the time point of detecting the utterance start; and detect an utterance end based on the suppressed utterance start direction sound pressure.

Abstract: A method for encoded-sound determination performed by a computer includes: executing a first process that includes obtaining information indicating intensities of sound signals, the frequencies being calculated from the sound signals and corresponding to frequencies; and executing a second process that includes determining whether or not the sound signals are signals of encoded sound, based on whether or not the intensities of the sound signals in predetermined frequency bands that are adjacent to each other in a frequency direction have a difference that is larger than or equal to a predetermined threshold.

Abstract: A method includes: generating a first and second shift signal by using a phase of a sound signal regarding an M-channel or a S-channel, the sound signal of the M-channel and the sound signal of the S-channel being obtained by using a mid-side microphone, the sound signal of the S-channel including a positive channel and a negative channel, the first shift signal being configured to reduce a phase difference caused by a difference between a sound arrival distance to the M-channel and a sound arrival distance to the positive channel of the S-channel, the second shift signal being configured to reduce a phase difference caused by a difference between the sound arrival distance to the M-channel and a sound arrival distance to the negative channel of the S-channel; and approximately converting the first or second shift signal into an L-channel signal and an R-channel signal of an XY-microphone.

Abstract: There is provided an audio encoding apparatus including a memory, and a processor coupled to the memory and the processor configured to determine whether a tone is included in a boundary between a low-frequency that is a frequency bandwidth below a predetermined frequency of an input signal and a high-frequency that is a frequency bandwidth above the predetermined frequency of the input signal, suppress a tone in one of the low-frequency and the high-frequency, encode the input signal having the low-frequency to generate a low-frequency code, encode the input signal having the high-frequency to generate a high-frequency code, and generate an encoded stream by multiplexing the low-frequency code and the high-frequency code.

Abstract: A sound-source-direction determining apparatus includes a processor that updates a reference threshold such that the reference threshold increases as a sound pressure difference increases, the sound pressure difference being a difference between sound pressure of a certain frequency component of sound acquired by the first microphone and sound pressure of the certain frequency component of the sound acquired by the second microphone when the synthesized sound is output from the speaker and determines a direction in which a sound source of sound is located, based on comparison between the reference threshold and a sound pressure difference between sound pressure of a certain frequency component of the sound acquired by the first microphone and sound pressure of the certain frequency component of the sound acquired by the second microphone when the synthesized sound is not output from the speaker.

Abstract: A speaker direction determination method includes acquiring a physical quantity indicating at least one of a phase difference and a sound pressure difference based on a plurality of sound signals acquired by the plurality of microphones; generating a correction model corrected such that the physical quantity in a correspondence in a reference model indicating the correspondence between a sound incidence angle onto the plurality of microphones in the case where the housing is located at the reference position and the physical quantity acquired in the case where the housing is located at the reference position corresponds to noise level indicated by the acquired noise information; setting the physical quantity corresponding to the sound incidence angle associated with the inclination indicated by the acquired inclination information in the correction model as a threshold; comparing the acquired physical quantity with the set threshold to determine a speaker direction.

Abstract: A method for utterance section detection includes: executing pitch gain calculation processing that includes calculating a pitch gain indicating an intensity of periodicity of an audio signal expressing a voice of a speaker for each of frames that are obtained by dividing the audio signal and that each have a predetermined length; and executing utterance section detection processing that includes determining that an utterance section on the audio signal starts when the pitch gain becomes greater than or equal to a first threshold value after a non-utterance section on the audio signal lasts, wherein the utterance section detection processing further includes determining that the utterance section ends when the pitch gain becomes less than a second threshold value lower than the first threshold value after the utterance section lasts.

Abstract: An utterance detection apparatus includes a processor configured to: detect an utterance start based on a first sound pressure based on first audio data acquired from a first microphone and a second sound pressure based on second audio data acquired from a second microphone; suppress an utterance start direction sound pressure when the utterance start direction sound pressure, which is one of the first sound pressure and the second sound pressure being larger at a time point of detecting the utterance start, falls below a non-utterance start direction sound pressure, which is the other one of the first sound pressure and the second sound pressure being smaller at the time point of detecting the utterance start; and detect an utterance end based on the suppressed utterance start direction sound pressure.

Abstract: A noise suppression method performed by a computer includes: obtaining input sound; detecting a cycle of power change in a non-voice segment included in the input sound; calculating a correction amount that periodically changes and is applied to a voice segment included in the input sound based on the cycle; and correcting power in at least the voice segment based on the correction amount.

Abstract: A non-transitory computer-readable recording medium stores therein a program for causing a computer to execute processing including: converting a speech recognition result of speech recognition performed on an input voice for each of a plurality of languages into a phoneme string; calculating a phoneme count for each of the plurality of languages from the corresponding one of the phoneme strings obtained by the conversion for the respective languages; and identifying a type of language matched with the input voice based on the phoneme counts calculated for the respective languages.

Abstract: A sound-source-direction determining apparatus includes a processor that updates a reference threshold such that the reference threshold increases as a sound pressure difference increases, the sound pressure difference being a difference between sound pressure of a certain frequency component of sound acquired by the first microphone and sound pressure of the certain frequency component of the sound acquired by the second microphone when the synthesized sound is output from the speaker and determines a direction in which a sound source of sound is located, based on comparison between the reference threshold and a sound pressure difference between sound pressure of a certain frequency component of the sound acquired by the first microphone and sound pressure of the certain frequency component of the sound acquired by the second microphone when the synthesized sound is not output from the speaker.

Abstract: A device for determining a sound source direction determines a direction in which a source of a reached sound exists, based on at least one of a sound pressure difference between a first sound pressure that is a sound pressure of a first frequency component of a first part of the reached sound acquired by a first microphone and a second sound pressure that is a sound pressure of the first frequency component of a second part of the reached sound acquired by a second microphone, and a phase difference between a first phase that is a phase of a second frequency component of the first part of the reached sound and a second phase that is a phase of the second frequency component of the second part of the reached sound.

Abstract: A non-transitory computer-readable storage medium storing a program that causes a processor included in a computer mounted on a sound source direction estimation device to execute a process, the process includes calculating a sound pressure difference between a first voice data acquired from a first microphone and a second voice data acquired from a second microphone and estimating a sound source direction of the first voice data and the second voice data based on the sound pressure difference, outputting an instruction to execute a voice recognition on the first voice data or the second voice data in a language corresponding to the estimated sound source direction, and controlling a reference for estimating a sound source direction based on the sound pressure difference, based on a time length of the voice data used for the voice recognition based on the instruction and a voice recognition time length.

Abstract: A method for encoded-sound determination performed by a computer includes: executing a first process that includes obtaining information indicating intensities of sound signals, the frequencies being calculated from the sound signals and corresponding to frequencies; and executing a second process that includes determining whether or not the sound signals are signals of encoded sound, based on whether or not the intensities of the sound signals in predetermined frequency bands that are adjacent to each other in a frequency direction have a difference that is larger than or equal to a predetermined threshold.

Abstract: An apparatus for speech processing: calculates a pitch gain indicating a magnitude of periodicity of an audio signal for each frame, the audio signal representing speaker's voice to be divided into the frames each having a predetermined length; determines that a speech production interval has started, when the pitch gain becomes equal or greater than a first threshold after a non-speech production interval; sets a second threshold that is lower than the first threshold by a reduction amount corresponding to a value acquired by subtracting a second representative value of the pitch gain in an interval preceding the start of the speech production interval from a first representative value of the pitch gain in the speech production interval; and determines that the speech production interval has terminated, when the pitch gain becomes smaller than the second threshold after the speech production interval has started.

Abstract: An abnormality detecting device includes a memory, and a processor coupled to the memory and configured to: detect an envelope of an audio signal indicating a periodic sound emitted by a target object and a periodic sound emitted by another object; execute time-to-frequency conversion on the envelope to calculate a frequency spectrum of the audio signal; and determine whether or not the target object has an abnormality, based on a frequency component included in the frequency spectrum and corresponding to a time interval between time points when the sound is emitted by the target object.

Abstract: An abnormality detecting device includes a processor coupled to a memory and configured to: detect an envelope of a sound signal representing a periodic sound emitted from the rotor including a predetermined number of blades and a periodic sound emitted from another object; perform a time frequency transform of the envelope for each of frames having a predetermined time length and calculate a frequency spectrum of the sound signal; detect a candidate of a frequency equivalent to a period of the sound emitted from the rotor; and obtain a duration in which a fluctuation in power with respect to power of a component of the frequency spectrum in the candidate detected with regard to the frame becomes lower than or equal to a certain level and identify the candidate in which the duration becomes longest as the frequency equivalent to the period of the sound emitted from the rotor.

Abstract: An abnormality detecting device includes a memory, and a processor coupled to the memory and configured to: detect an envelope of an audio signal indicating a periodic sound emitted by a target object and a periodic sound emitted by another object; execute time-to-frequency conversion on the envelope to calculate a frequency spectrum of the audio signal; and determine whether or not the target object has an abnormality, based on a frequency component included in the frequency spectrum and corresponding to a time interval between time points when the sound is emitted by the target object.