Pioneer Electronic Corporation

Pioneer Video Corporation

Soichi Toyama

Kazuo Watanabe

Hiroyuki Ishihara

Makio Yamaki

Kazunaga Ida

A harmonic tone generator produces a harmonics signal even for input audio signals of a small amplitude. Conversion of a digitized audio signal in accordance with a predetermined non-linear function is performed also for an audio signal of a small amplitude. According to the second aspect of the invention, a level difference between the digital audio signal level in the present sampling time and the audio signal level in the preceding sampling time is detected and the detected level difference is converted to an output value in accordance with a predetermined non-linear function by a non-linear converting circuit. The converted output value is accumulated. According to the third aspect of the invention, the detected level difference is converted to a function conversion output in accordance with a predetermined function by a non-linear converting circuit. A gain of an amplifier to amplify the audio signal in the present sampling time is changed in accordance with the function conversion output.

Harmonic tone generator for low level input audio signals and small

A pitch control apparatus which suppresses the occurrence of a tremolo tone which the interval control is performed. Input audio signal data is written at a memory position at a designated writing address in a memory in a predetermined order for every sampling cycle, a plurality of reading addresses of the memory are designated for every sampling cycle, and are set in a different order from the predetermined order for each cycle which is a multiple of the sampling cycle by a predetermined multiplier, data is read from memory positions of designated plurality of reading addresses in the memory, a coefficient is set in accordance with an address interval between the writing address and each of the designated plurality of reading addresses in the memory, the data read out at the plurality of reading addresses are multiplied by the associated coefficients, and the results are added together as output data. The maximum value of interval between each of the plurality of reading addresses, Dmax, is set as

Pitch control apparatus for setting coefficients for cross-fading

A sound echo machine as an acoustic signal processing unit of the present invention comprising an adder to which an input signal is fed, and a delay circuit for delaying the signal fed from the adder for a certain time to repeatedly feed back to the adder to generate an echo sound further comprises an input signal level detector for detecting the level of the input signal and sending it to a frequency oscillator to vary the oscillating frequency in accordance with the thus detected signal level for feeding it later to the delay circuit so as to modulate the time to be delayed at a predetermined cycle, whereby it can create an acoustic field in which a listener can feel as if various level of reflected sounds are coming towards him from various directions. On the other hand, a sound effecter as an acoustic signal processing unit comprising a plurality of acoustic signal processing sections, a plurality of attenuators each connected to these acoustic signal processing sections, and an adder for summing up all the signals from these attenuators further comprises a signal mixing ratio control section for monitoring the input acoustic signal level, and determining a signal mixing ratio among the respective output signals from the plurality of acoustic signal processing sections in accordance with the thus monitored level of the input acoustic signal, whereby even a simple structure can provide a specific sound effect.

Acoustic signal processing unit

A digital signal processing device for outputting a holding data in an output register from a DSP in synchronism with a second clock pulse having a frequency lower than that of a first clock pulse for conducting arithmetic processing in the DSP. Accordingly, data to be output from the DSP can be directly read by a microcomputer, and contents in a coefficient memory and a delay time memory, for example, can be updated in accordance with the read data. Further, the digital signal processing device can be applied to an audio apparatus such as a loudness controller and a spectrum indicating apparatus.

Growing community of inventors

Tokyo, Japan

Soichi Toyama