Abstract: According to one embodiment, a compensation filtering device includes an impulse response calculator, a coefficient calculator, and an adder. The impulse response calculator calculates an impulse response of a reproduction system comprising a sound field. The coefficient calculator calculates a compensation coefficient to compensate for a tap coefficient such that a direct current gain of an extracted finite impulse response (FIR) filter with a predetermine number of taps extracted from an FIR filter having reverse characteristics of the impulse response takes a predetermined value. The tap coefficient indicates a weight of each of the taps. The adder adds the compensation coefficient to the tap coefficient of each of the taps of the extracted FIR filter to generate a compensation filter to compensate for acoustic characteristics of the reproduction system.

Abstract: According to one embodiment, audio correction apparatus connected to audio player, includes output module configured to output audio signal as sound, and filter configured to correct the audio signal based on tap coefficient is provided. The apparatus includes, audio measurement module configured to pick up plurality of recording signals obtained by recording sound output from output module at detection points located at different points, audio analyzer configured to calculate plurality of frequency responses based on plurality of recording signals obtained by audio measurement module, and audio correction module configured to calculate maximum amplitude response by specifying maximum amplitude for each of frequencies, to calculate average group delay property for each of frequencies, to calculate tap coefficient based on maximum amplitude and average group delay property, and to output tap coefficient to filter of audio player.

Abstract: According to one embodiment, an acoustic correction apparatus includes an input module, a calculator, a divider, a converter, an extractor, a synthesizer, and a generator. The input module receives an audio signal propagated through a sound field. The calculator calculates an impulse response from the audio signal. The divider divides the impulse response into first and second impulse responses. The converter converts the first and second impulse responses into first and second frequency spectrums. The extractor specifies an amplitude component of the first frequency spectrum with a peak relatively higher than that of the amplitude component of the first frequency spectrum, and extracts the peak as a resonance component. The synthesizer synthesizes a first property and a second property for attenuating the resonance component. The generator generates a correction filter for performing correction to obtain the synthesized property.

Abstract: According to one embodiment, an apparatus for cancelling resonance in an outer-ear canal, comprises an outer-ear canal model includes attenuator modules representing reflection coefficients of an earphone or headphone and an eardrum, and a delay module having a delay time corresponding to a distance between the earphone or headphone and the eardrum, an inverse-filter forming unit configured to form an inverse filter of the outer-ear canal model, and a convolution module configured to perform convolution on an impulse response from the inverse filter and a sound-source signal.

Abstract: According to one embodiment, an acoustic characteristic correction coefficient calculation apparatus includes a frequency converter, a smoother, a frequency inverter, a cutter, and a calculator. The frequency converter is configured to convert a first impulse response corresponding to an input acoustic signal to a frequency domain. The smoother is configured to smooth amplitude and phase corresponding to the frequency domain converted by the frequency converter. The frequency inverter is configured to convert a frequency characteristic smoothed by the smoother to a time domain. The cutter is configured to cut out a second impulse response configured by the time domain obtained by converting the frequency characteristic by use of the frequency inverter by a preset tap number. The calculator is configured to calculate a correction coefficient used to correct an acoustic characteristic based on a result cut out by the cutter.

Abstract: According to one embodiment, an acoustic correction apparatus includes: a signal obtaining module configured to obtain an acoustic signal from a target space including an object and an external space; a signal output module configured to output to the target space a measurement signal; a coefficient identifying module configured to identify, on the basis of a response acoustic signal, a correction coefficient of a correction filter that reduces a resonance frequency component of a resonance in the object; a filtering module configured to use the correction filter, and filter the signal provided to the object; a noise cancelling module configured to remove, on the basis of the acoustic signal, a noise component comprised in the acoustic signal from the filtered signal; and an output module configured to output the acoustic signal, from which the noise component is removed by the noise cancelling module, to the object.

Abstract: An audio signal compensation device includes: a signal processor configured to perform filtering on an input audio signal; a filter coefficients storage module configured to store a plurality of filter coefficients; a user interface configured to provide options for a determination of filter coefficients to a user and to obtain a selection result from the user; and a filter coefficients determining module configured to determine a set of filter coefficients among the plurality of filter coefficients based on the selection result.

Abstract: According to one embodiment, an acoustic apparatus comprises an electro-acoustic transducer with a first function of converting an electric signal to an acoustic signal and a second function of converting an acoustic signal to an electric signal, the electro-acoustic transducer configured to convert a measuring electric signal to a measuring acoustic signal using the first function, and to convert an acoustic response signal responding to the measuring acoustic signal from an object to an electric response signal using the second function, a switch configured to switch the first function to the second function, or vice versa, and a switch controller configured to control a function switching of the switch in accordance with a sound source signal.

Abstract: According to one embodiment, a sound processor includes a creating module, a filter, and a combining module. The creating module creates a plurality of first acoustic models based on a frequency characteristic that represents an acoustic property of an object to be measured. The first acoustic models are modeled with respect to resonance properties that vary depending on frequency bands. The filter extracts frequency components in the frequency bands from the respective first acoustic models. The combining module combines the frequency components extracted from the first acoustic models to create a second acoustic model.

Abstract: According to one embodiment, a threshold adjusting apparatus for a clocked comparator, the clocked comparator comparing an input signal with a threshold in accordance with a clock, the threshold adjusting apparatus comprises an output detection module configured to detect an output from the clocked comparator with the threshold while changing the threshold and a setting module configured to set the threshold when the output detection module detects a change in the output from the clocked comparator as an adjusted threshold.

Abstract: According to one embodiment, an acoustic apparatus comprises a measuring signal generator, a transducer configured to convert a measuring signal to a measuring sound and to convert a characteristic vibration of the transducer due to the measuring sound, to a characteristic vibration signal, an analysis module configured to analyze the characteristic vibration signal in order to output a physical quality of a characteristic vibration of the transducer, a controller configured to set a first state in which the transducer converts an electric signal to an acoustic signal or a second state in which the transducer converts an acoustic signal to an electric signal. The measuring signal generator is connected to the transducer in the first state and the analysis module is connected to the transducer in the second state.

Abstract: According to one embodiment, an infrared signal decode circuit includes: a comparator; a correlation signal generator generating a sum of a first detection signal and a second detection signal as a correlation signal, the first detection signal being obtained by performing an absolute value calculation on a first correlation signal, the second detection signal being obtained by performing an absolute value calculation on a second correlation signal, the first correlation signal corresponding to a correlation between a binary signal and a first reference signal with a frequency substantially identical to a base frequency of a subcarrier of an infrared signal, the second correlation signal corresponding to a correlation between the binary signal and a second reference signal with a phase that differ from a phase of the first reference signal by 90 degrees; and a decoder binarizing the correlation signal generated by the correlation signal generator.

Abstract: According to one embodiment, an acoustic correction apparatus includes: a signal obtaining module configured to obtain an acoustic signal from a target space including an object and an external space; a signal output module configured to output to the target space a measurement signal; a coefficient identifying module configured to identify, on the basis of a response acoustic signal, a correction coefficient of a correction filter that reduces a resonance frequency component of a resonance in the object; a filtering module configured to use the correction filter, and filter the signal provided to the object; a noise cancelling module configured to remove, on the basis of the acoustic signal, a noise component comprised in the acoustic signal from the filtered signal; and an output module configured to output the acoustic signal, from which the noise component is removed by the noise cancelling module, to the object.

Abstract: According to one embodiment, A microphone-earphone includes a speaker connected to an acoustic device configured to measure acoustic characteristics of a listener's external auditory canal, and configured to output an acoustic signal toward the listener's external auditory canal, a microphone device disposed outside the listener's external auditory canal, an acoustic tube including one end connected to the microphone device and the other end opening to the listener's external auditory canal, and a housing including an opening portion which accommodates the speaker and is so disposed as to guide sound, which is output from the speaker, to the listener's external auditory canal. An inside diameter of the acoustic tube is less than a diameter of the opening portion.

Abstract: According to one embodiment, a signal processing apparatus, includes: an output module configured to output a sound source signal to an external environment; a receiver configured to receive a response signal responding to the sound source signal output by the output module; an extracting module configured to extract a noise component signal from the response signal received by the receiver using an inverse filtering process of a frequency characteristic, the frequency characteristic being set in advance by dividing a measurement response signal responding to a measurement sound source signal used to measure the external environment from the measurement source signal, the measurement source signal being one of the sound source signal output by the output module; and a removing module configured to remove the noise component signal from the sound source signal output by the output module after the extraction of the noise component signal.

Abstract: According to one embodiment, an infrared signal decode circuit includes: a comparator; a correlation signal generator generating a sum of a first detection signal and a second detection signal as a correlation signal, the first detection signal being obtained by performing an absolute value calculation on a first correlation signal, the second detection signal being obtained by performing an absolute value calculation on a second correlation signal, the first correlation signal corresponding to a correlation between a binary signal and a first reference signal with a frequency substantially identical to a base frequency of a subcarrier of an infrared signal, the second correlation signal corresponding to a correlation between the binary signal and a second reference signal with a phase that differ from a phase of the first reference signal by 90 degrees; and a decoder binarizing the correlation signal generated by the correlation signal generator.

Abstract: According to one embodiment, a sound corrector includes a signal outputter, a response signal, a frequency specifier, a coefficient specifier, a filter, and an outputter. The signal outputter outputs a measurement signal to measure acoustical properties of an object to be measured. The response signal receiver receives a response signal from the object in response to the measurement signal. The frequency specifier specifies a resonant frequency at a resonance peak from the response signal. The coefficient specifier specifies a correction coefficient of a correction filter for reducing the resonant frequency based on the specified resonant frequency. The filter performs filtering on a signal to be output to the object using the correction filter with the correction coefficient. The outputter outputs the signal having undergone the filtering to the object.

Abstract: According to one embodiment, a sound processor includes a creating module, a filter, and a combining module. The creating module creates a plurality of first acoustic models based on a frequency characteristic that represents an acoustic property of an object to be measured. The first acoustic models are modeled with respect to resonance properties that vary depending on frequency bands. The filter extracts frequency components in the frequency bands from the respective first acoustic models. The combining module combines the frequency components extracted from the first acoustic models to create a second acoustic model.

Abstract: According to one embodiment, an acoustic apparatus comprises a measuring signal generator, a transducer configured to convert a measuring signal to a measuring sound and to convert a characteristic vibration of the transducer due to the measuring sound, to a characteristic vibration signal, an analysis module configured to analyze the characteristic vibration signal in order to output a physical quality of a characteristic vibration of the transducer, a controller configured to set a first state in which the transducer converts an electric signal to an acoustic signal or a second state in which the transducer converts an acoustic signal to an electric signal. The measuring signal generator is connected to the transducer in the first state and the analysis module is connected to the transducer in the second state.

Abstract: According to one embodiment, an acoustic apparatus comprises an electro-acoustic transducer with a first function of converting an electric signal to an acoustic signal and a second function of converting an acoustic signal to an electric signal, the electro-acoustic transducer configured to convert a measuring electric signal to a measuring acoustic signal using the first function, and to convert an acoustic response signal responding to the measuring acoustic signal from an object to an electric response signal using the second function, a switch configured to switch the first function to the second function, or vice versa, and a switch controller configured to control a function switching of the switch in accordance with a sound source signal.