Iwao Higashi

Method of detecting localization of acoustic image and acoustic image localizing system

A method of detecting localization of an acoustic image, in which an acoustic impulse is emitted from a sound source to a dummy of a human head, an acoustic sensor is provided to a portion of the dummys ears, and the response waveform is received by the acoustic sensor. This enables the detection of what effects are derived from interruption, reflection, and the like of a tone due to the human head. The received response waveform is analyzed and parameters for an acoustic image localization system are obtained. The acoustic image localization system comprising a delay circuit, a filter and an amplification controller sets the parameters into the delay circuit, the filter and the amplification controller, so that the detected localization of an acoustic image is reproduced.

Musical tone synthesizing apparatus utilizing an all-pass filter having a variable fractional delay

The musical tone synthesizing apparatus is mainly configured by a closed loop which at least provides a delay circuit and an all-pass filter. The delay circuit delays an input signal (e.g., excitation wave signal) by a first delay time corresponding to a certain integral number of sampling periods. The all-pass filter functions to at least delay an output of the delay circuit by a second delay time corresponding to a decimal fraction of the sampling period, so that an output of the all-pass filter is fed back to the delay circuit. The whole delay time of the closed loop consists of the first and second delay times which can be respectively controlled. Thus, a musical tone signal representing a synthesized musical tone (e.g., an attenuating sound which is produced from an percussion instrument) is picked up from the closed loop. Incidentally, the whole configuration of the closed loop can be embodied by a digital signal processor (DSP).

Resonant effect apparatus for electronic musical instrument

A resonant effect apparatus for an electronic musical instrument includes a plurality of resonant tone signal forming channels for forming a plurality of resonant tone signals different in their resonant frequency characteristics when applied with a musical tone to be generated and a plurality of acoustic conversion systems for acoustically converting each of the resonant tone signals to issue the converted resonant tone signals therefrom. In the resonant effect apparatus, a supply condition of the resonant tone signals to the acoustic conversion systems is controlled for control of a sound localization of the resonant tone signals.

Electronic musical instrument capable of simulating small pitch variation at initiation of musical tone generation

An electronic musical instrument: is provided to perform an active control on the pitch of the musical tone to be generated, thereby simulating the pitch-rising phenomenon to be occurred in the performance of a non-electronic musical instrument such as a wind instrument, percussion instrument and stringed instrument. In case of the simulation of the wind instrument, this electronic musical instrument is mainly configured by an excitation-vibration circuit and a tube simulation circuit which are connected together by means of a junction. The tube simulation circuit is configured by a closed-loop circuit in which plural delay circuits and junction circuits are connected together in cascade-connection manner. Herein, the delay circuits simulate the propagation delay of the air-pressure wave to be transmitted through the tube of the wind instrument, while the junction circuits simulate the scattering manner of the air-pressure wave at the points at which the diameter of the tube is changed. The number of the delay stages which are required to simulate the musical sound is controlled to be changed in a lapse of time.