Abstract: A method of constructing a database in an on-vehicle device includes the steps of connecting a mobile terminal storing a plurality of pieces of music and music information associated with each of the plurality of pieces of music, acquiring the music information of each piece of music from the mobile terminal, when the acquired music information is stored in a storage space, determining whether free capacity of the storage space is insufficient, and when it is determined that the free capacity of the storage space is insufficient, removing at least one piece of music information of each piece of music from the storage space, and constructing a database for searching music on the basis of the music information stored in the storage space.

Abstract: When an instruction to start voice input is received from the user, a gain controller acquires, from a gain table which defines a correspondence between vehicle speed ranges and gains, a gain corresponding to a vehicle speed range including the vehicle speed of a vehicle detected by a vehicle speed detector, and sets the acquired gain as the gain of an input amplifier that amplifies an input audio signal output by a microphone. As a gain corresponding to each vehicle speed range, the gain table records a gain of the input amplifier corresponding, in an experimentally determined frequency distribution of peak values in the vehicle speed range, to a maximum frequency in the range of magnitude of voice output as an input audio signal by the microphone and to be input to a speech recognition engine as voice having a magnitude within the input range of the speech recognition engine.

Abstract: A method of constructing a database in an on-vehicle device includes the steps of connecting a mobile terminal storing a plurality of pieces of music and music information associated with each of the plurality of pieces of music, acquiring the music information of each piece of music from the mobile terminal, when the acquired music information is stored in a storage space, determining whether free capacity of the storage space is insufficient, and when it is determined that the free capacity of the storage space is insufficient, removing at least one piece of music information of each piece of music from the storage space, and constructing a database for searching music on the basis of the music information stored in the storage space.

Abstract: When an instruction to start voice input is received from the user, a gain controller acquires, from a gain table which defines a correspondence between vehicle speed ranges and gains, a gain corresponding to a vehicle speed range including the vehicle speed of a vehicle detected by a vehicle speed detector, and sets the acquired gain as the gain of an input amplifier that amplifies an input audio signal output by a microphone. As a gain corresponding to each vehicle speed range, the gain table records a gain of the input amplifier corresponding, in an experimentally determined frequency distribution of peak values in the vehicle speed range, to a maximum frequency in the range of magnitude of voice output as an input audio signal by the microphone and to be input to a speech recognition engine as voice having a magnitude within the input range of the speech recognition engine.

Abstract: In a voice intelligibility enhancement system that controls a gain of a voice signal based on noise power and voice power of the voice signal generated by a voice signal generation unit, it is detected whether the voice power is equal to or greater than a predetermined level, noise power output when the voice power is less than the predetermined level is measured and stored, noise power to be output when the voice power exceeds the predetermined level is estimated to be the stored noise power, and gain of a voice signal is controlled on the basis of the voice power and the estimated noise power.

Abstract: In an apparatus for improving voice clarity by controlling a gain of a voice based on a sound pressure level of the voice and a sound pressure level of noise, it is determined whether a sound pressure level of a gain-controlled voice exceeds a maximum allowable level. If the sound pressure level exceeding the maximum allowable level is caused by audio sound, a sound pressure level of the audio sound is reduced. The sound pressure level of the audio sound is minimally reduced so that the sound pressure level of the voice becomes equal to or lower than the maximum allowable level.

Abstract: If a delay occurs in execution of sound/voice processing application software, and, as a result, MIC data is stored in a plurality of buffers, then a CPU identifies, based on a buffer list, a buffer in which newest MIC data is stored. The CPU reads the newest MIC data from the identified buffer and adjusts an output sound/voice level depending on an external sound/voice level, using the newest MIC data.

Abstract: In a voice intelligibility enhancement system that controls a gain of a voice signal based on noise power and voice power of the voice signal generated by a voice signal generation unit, it is detected whether the voice power is equal to or greater than a predetermined level, noise power output when the voice power is less than the predetermined level is measured and stored, noise power to be output when the voice power exceeds the predetermined level is estimated to be the stored noise power, and gain of a voice signal is controlled on the basis of the voice power and the estimated noise power.

Abstract: A voice recognition system includes an adaptive filter and a subtractor. The adaptive filter generates a simulated talk-back voice y(n) by setting a filter coefficient simulating a transfer system in which an input voice corresponding to a voice command and a talk-back voice output from a speaker are input into a microphone and by filtering a talk-back voice x(n). The subtractor extracts the input voice by subtracting the simulated talk-back voice y(n) from mixed sound input into the microphone. With this configuration, the talk-back voice is attenuated from the mixed sound including the input voice and the talk-back voice input tedinto the microphone, and then, the mixed sound is supplied to a voice recognition engine. Accordingly, the user can input his/her voice during a talk-back operation without the need to interrupt it by pressing a speech button every time the user wishes to input the voice. The voice recognition operation time can be thus reduced.

Abstract: A speech correction apparatus includes a speaker for generating guidance speech; a microphone set at a hearing position; an acoustic-characteristic setting unit for separating ambient noise from the guidance speech at the hearing position; an operating unit; a speech correcting filter for correcting the sound pressure level of the guidance speech generated by the speaker based on the average power of the guidance speech and the average power of the ambient noise which are separated; a loudness-compensating-gain calculating unit; and a speech-head correcting unit for correcting the average power of the guidance speech corresponding to the speech head at the border between a silent state and a speech state of the guidance speech.

Abstract: An audio correcting apparatus includes a speaker provided on a television apparatus, a microphone provided on a remote controller, an identifying unit which identifies an acoustic characteristic from the speaker to the microphone, and an acoustic characteristic setting unit having the acoustic characteristic. A signal obtained by allowing an audio signal input to the speaker to pass through the acoustic characteristic setting unit, and a signal representing ambient noise are input to an audio-correcting filter and a loudness-compensation-gain calculating unit. Based on both signals, the sound pressure level of sound output from the speaker is corrected so that the sound output from the speaker is clearly heard when reaching the user without being affected by the ambient noise.

Abstract: On the basis of status information on a vehicle collected by a status information input interface from a navigation device, an ECU, and sensors, an S/N ratio estimating unit estimates, as an S/N ratio, the level of the ratio between the power of a component corresponding to audio-device output sound y(j) and that corresponding to noise sound n(j) contained in a microphone output signal. A transfer-function variation estimating unit estimates the level of a variation in a transfer function of an audio-device output audio signal transfer system. An adaptive characteristics controller controls a characteristic of a coefficient updating operation of a tap coefficient of an FIR filter performed by a coefficient updating unit of an adaptive filter, i.e., an adaptation (learning) characteristic of the adaptive filter, in response to the S/N ratio level and the level of the variation in the transfer function.

Abstract: Acoustic outputs from an audio system and various acoustic output devices are produced from a speaker, and a sound which a user desires to hear clearly is automatically selected and corrected with emphasis. A TV sound, an acoustic guide of a navigation system, and a sound on the other end of a hands-free device are delivered to a selector, and one of them is selected by a selector switching control and corrected by an acoustic correction filter to be produced. The other acoustic signals are produced as non-correction target signals together with an audio signal.

Abstract: In an apparatus for improving voice clarity by controlling a gain of a voice based on a sound pressure level of the voice and a sound pressure level of noise, it is determined whether a sound pressure level of a gain-controlled voice exceeds a maximum allowable level. If the sound pressure level exceeding the maximum allowable level is caused by audio sound, a sound pressure level of the audio sound is reduced. The sound pressure level of the audio sound is minimally reduced so that the sound pressure level of the voice becomes equal to or lower than the maximum allowable level.

Abstract: Voice output device and method to generate voice messages that are highly comprehensible. The voice output device includes a voice database in which information indicating the familiarity level of each word or word string has been recorded, and a sound pressure adjustor for adjusting the sound pressure level of each word or word string on the basis of voice data and familiarity information read together with voice data from the voice database by a reproducer. For a word or the like having low familiarity, the sound pressure thereof is corrected by increasing it. Thus, to generate a voice message including a word of low familiarity, such as an unfamiliar place name, adjustment is performed so that the unfamiliar place name is generated with a higher sound pressure, as compared with a word of high familiarity. This allows words with low familiarity to be easily comprehended.

Abstract: A speech correction apparatus includes a speaker for generating guidance speech; a microphone set at a hearing position; an acoustic-characteristic setting unit for separating ambient noise from the guidance speech at the hearing position; an operating unit; a speech correcting filter for correcting the sound pressure level of the guidance speech generated by the speaker based on the average power of the guidance speech and the average power of the ambient noise which are separated; a loudness-compensating-gain calculating unit; and a speech-head correcting unit for correcting the average power of the guidance speech corresponding to the speech head at the border between a silent state and a speech state of the guidance speech.

Abstract: An audio correcting apparatus includes a speaker provided on a television apparatus, a microphone provided on a remote controller, an identifying unit which identifies an acoustic characteristic from the speaker to the microphone, and an acoustic characteristic setting unit having the acoustic characteristic. A signal obtained by allowing an audio signal input to the speaker to pass through the acoustic characteristic setting unit, and a signal representing ambient noise are input to an audio-correcting filter and a loudness-compensation-gain calculating unit. Based on both signals, the sound pressure level of sound output from the speaker is corrected so that the sound output from the speaker is clearly heard when reaching the user without being affected by the ambient noise.

Abstract: A voice recognition system includes an adaptive filter and a subtractor. The adaptive filter generates a simulated talk-back voice y(n) by setting a filter coefficient simulating a transfer system in which an input voice corresponding to a voice command and a talk-back voice output from a speaker are input into a microphone and by filtering a talk-back voice x(n). The subtractor extracts the input voice by subtracting the simulated talk-back voice y(n) from mixed sound input into the microphone. With this configuration, the talk-back voice is attenuated from the mixed sound including the input voice and the talk-back voice input tedinto the microphone, and then, the mixed sound is supplied to a voice recognition engine. Accordingly, the user can input his/her voice during a talk-back operation without the need to interrupt it by pressing a speech button every time the user wishes to input the voice. The voice recognition operation time can be thus reduced.

Abstract: A transmission-speech extraction filter extracts speech to be transmitted from the output signal of a transmission-speech microphone by using the proximity effect. A background-sound extraction filter extracts background sound from the output signal of the transmission-speech microphone. A background sound level calculation section calculates the level of the extracted background sound in each frequency band, and sends the level to a loudness-compensation control section as a background-sound level. The loudness-compensation control section controls the amount of gain adjustment for a received-speech signal in each frequency band in a gain adjustment section according to the background-sound level and the received-speech level of a received-speech signal, calculated in a received-speech-level calculation section.

Abstract: Acoustic outputs from an audio system and various acoustic output devices are produced from a speaker, and a sound which a user desires to hear clearly is automatically selected and corrected with emphasis. A TV sound, an acoustic guide of a navigation system, and a sound on the other end of a hands-free device are delivered to a selector, and one of them is selected by a selector switching control and corrected by an acoustic correction filter to be produced. The other acoustic signals are produced as non-correction target signals together with an audio signal.