Abstract: An engine sound processing apparatus includes an engine sound signal generating section that generates an engine sound signal indicating an engine sound generated in an engine room of a vehicle, a signal processing section that includes a reverberation effect applying portion which applies a reverberation effect to the engine sound signal and a mixing portion which mixes the engine sound signal to which the reverberation effect is not applied and the engine sound signal to which the reverberation effect is applied, a reverberation effect controlling section that instructs the reverberation effect applying portion to apply the reverberation effect to the engine sound signal, a mixing balance setting section that sets a mixing balance in the mixing portion, and a speaker that outputs a sound on the basis of the engine sound signal being output from the signal processing section.

Abstract: Band-pass filter suppresses frequency components of a sound signal that are lower than a low-side cutoff frequency and that are higher than a high-side cutoff frequency. Pitch detection section detects a pitch of the sound signal having been processed by the band-pass filter. Target setting section variably sets a low-side target value lower than the pitch detected by the pitch detection section and a high-side target value higher than the detected pitch. Filter control section causes the low-side cutoff frequency to approach the low-side target value over time and causes the high-side cutoff frequency to approach the high-side target value over time. In this way, a pass band of the band-pass filter can be smoothly variably controlled in accordance with pitch change of the sound signal that is an object of pitch detection.

Abstract: Band-pass filter suppresses frequency components of a sound signal that are lower than a low-side cutoff frequency and that are higher than a high-side cutoff frequency. Pitch detection section detects a pitch of the sound signal having been processed by the band-pass filter. Target setting section variably sets a low-side target value lower than the pitch detected by the pitch detection section and a high-side target value higher than the detected pitch. Filter control section causes the low-side cutoff frequency to approach the low-side target value over time and causes the high-side cutoff frequency to approach the high-side target value over time. In this way, a pass band of the band-pass filter can be smoothly variably controlled in accordance with pitch change of the sound signal that is an object of pitch detection.

Abstract: An engine sound processing apparatus includes an engine sound signal generating section that generates an engine sound signal indicating an engine sound generated in an engine room of a vehicle, a signal processing section that includes a reverberation effect applying portion which applies a reverberation effect to the engine sound signal and a mixing portion which mixes the engine sound signal to which the reverberation effect is not applied and the engine sound signal to which the reverberation effect is applied, a reverberation effect controlling section that instructs the reverberation effect applying portion to apply the reverberation effect to the engine sound signal, a mixing balance setting section that sets a mixing balance in the mixing portion, and a speaker that outputs a sound on the basis of the engine sound signal being output from the signal processing section.

Abstract: A data converting device includes a first receiving section which receives vehicle driving data of a vehicle from an engine control unit for performing driving control of an engine mounted on the vehicle, and a control section which converts the vehicle driving data into a music performance format, and outputs the converted data.

Abstract: In a sound image creating apparatus, a distance computation section computes intermediate positions of a moving point along a trajectory line from a movement start position to a movement end position, and further computes a variable distance between each of the intermediate positions of the moving point and a fixed point. A velocity computation section computes a variable velocity of the moving point relative to the fixed point along the time axis on the basis of the variable distance. A signal processing section attenuates or delays an input sound signal in accordance with the variable distance, and varies a pitch of the input sound signal on the basis of the variable velocity, thereby creating the sound image of the input sound signal along the time axis based on principle of Doppler effect.

Abstract: In a sound image creating apparatus, a distance computation section computes intermediate positions of a moving point along a trajectory line from a movement start position to a movement end position, and further computes a variable distance between each of the intermediate positions of the moving point and a fixed point. A velocity computation section computes a variable velocity of the moving point relative to the fixed point along the time axis on the basis of the variable distance. A signal processing section attenuates or delays an input sound signal in accordance with the variable distance, and varies a pitch of the input sound signal on the basis of the variable velocity, thereby creating the sound image of the input sound signal along the time axis based on principle of Doppler effect.

Abstract: A reverberation generating apparatus is designed for applying a reverberation effect to an acoustic signal for output based on sampling data representative of an impulse response waveform. In the apparatus, a first convolution operating section convolutes the acoustic signal with sampling data corresponding to an initial period of the impulse response waveform so as to generate an initial acoustic signal. The initial period of the impulse response waveform is determined from a point of impulse sound emission to a point after a lapse of a specified time. A second convolution operating section convolutes the acoustic signal with sampling data corresponding to a selected period of the impulse response waveform so as to generate an additional acoustic signal. An attenuation operating section recurrently outputs the additional acoustic signal while attenuating the additional acoustic signal so as to generate a late acoustic signal.

Abstract: Most appropriate data of a plurality of level-converted digital data obtained by level conversion of the same input digital data by different conversion factors is selected based on a signal quality of each level-converted digital data. The other level-converted digital data is attenuated to or below a predetermined noise level. Switching between previously selected data and newly selected data is effected by cross-fading. The level-converted digital data are D/A converted to respective analog signals. Level conversion of the analog signals are carried out again based on respective corresponding ones of the conversion factors to restore a level of the input digital data, and all the level-converted analog signals are then added together.

Abstract: The most appropriate data of a plurality of level-converted digital data, obtained by level conversion of the input digital data by different conversion factors, is selected based on a signal quality of each of the level converted digital data. The other data of the level-converted digital data is attenuated to or below a predetermined noise level. Switching between previously selected data and newly selected data is effected by cross-fading. The level-converted digital data are D/A converted to respective analog signals.

Abstract: A D/A conversion apparatus includes a DSP which receives and converts input digital data with different conversion factors, to generate a plurality of digital data having different levels, selects one of the plurality of the generated digital data, depending upon the signal quality of the input digital data, while attenuating the other digital data to be lower than a predetermined noise level. A plurality of D/A converting devices convert the respective generated digital data into corresponding analog signals. A re-converting device converts the level of each of the analog signals into an original level, based on a corresponding one of the conversion factors with which the input digital data is converted by the DSP. An adding device adds the re-converted analog signals.

Abstract: In an echo effector for imparting an echo effect to an audio signal based on values of a plurality of parameters, a memory is provided for memorizing an interrelationship among the plurality of the parameters which are mutually related to each other. A dial is actuated for independently setting one or more of the parameters to desired values. A microcomputer dependently sets the remaining parameters to appropriate values according to the desired values and the memorized interrelationship. Further, in a sound field effector operative according to a selected program for creating an effect simulative of a sound field in matching with a room situation under which the effector is installed, a program memory stores a plurality of programs which can be selected in terms of types of sound fields and types of room situations. A first switch is operated for designating a desired type of a sound field. A second switch is operated for designating a desired type of a room situation.

Abstract: In an apparatus for amplifying a sound while suppressing a howling noise, a microphone collects a sound and converts the collected sound into a corresponding input signal. An amplifier amplifies the input signal to generate the sound through a loudspeaker. A plurality of equalizers are interposed between the microphone and the amplifier, each equalizer having a variable attenuation frequency for attenuatively filtering the input signal around the attenuation frequency. Detection is conducted for detecting a plurality of noise spectrum peaks of the howling noise contained in the collected sound. Then, an adjustment is conducted adjusting respective variable attenuation frequencies of the plurality of the equalizers correspondingly to the plurality of the detected noise spectrum peaks to thereby remove the howling noise from the generated sound.

Abstract: A harmony chorus apparatus collects an original of a vocal sound performed after a main melody pattern of a song, and adds a chorus sound derived after a chorus melody pattern of the same song to the vocal sound. A memory stores a main melody data representative of the main melody pattern and a chorus melody data representative of the chorus melody pattern which is designed in harmony with the main melody pattern. A pitch difference calculator sequentially retrieves the main melody data and the chorus memory data from the memory in synchronization with progression of the song, and calculates a pitch difference between the main melody pattern and the chorus memory pattern according to the retrieved main melody data and chorus melody data. A chorus generator shifts a pitch of the collected vocal sound by the calculated pitch difference to generate the chorus sound in the form of a variation of the vocal sound.

Abstract: A howling prevention apparatus prevents a howling noise which is generated in a sound amplification system using a microphone and a loudspeaker. The howling prevention apparatus utilizes a plural number of first to n-th equalizers, which have a variable frequency response and which modulate an output of the microphone. A detector detects a frequency point at which a loop gain of the system reaches a peak while supplying a standard noise signal to the loudspeaker to produce a test sound and measuring the sound collected by the microphone through the series of the equalizers. A frequency response of the first equalizer is adjusted to suppress a noise peak at and around a frequency point detected by the detector. Then, a frequency response of the second equalizer is also adjusted to suppress a noise peak at and around another frequency point detected by the detector. Lastly, a frequency response of the n-th equalizer is adjusted by subsequently repeating the above setting procedure.

Abstract: An audio reproduction characteristic control device reproduces various sound fields by producing reflected sounds of a reproduced source signal. Frequency response characteristic correction parameters for correcting a frequency response characteristic which varies with a reproduction environment to a standard characteristic or other predetermined characteristic is prestored in a memory and one of these parameters is read out in accordance with a designated reproduction environment and, if necessary, additionally with a designated sound field whereby the frequency response characteristic is corrected. In another aspect of the invention, reflected sound signals for front left, front right, rear left and rear right positions of a designated sound field are generated by operating input source signals with reflected sound characteristic parameters and these reflected sound signals are added to the source signals to be propagated from four directions in a space inside of an automobile.