JPS5952438B2 - sound generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sound generation device including a sound source and a digital filter, and in particular, by providing several types of periodic sound sources as periodic sound sources in a sound source circuit, To provide a sound generating device capable of alternately generating many types of sounds with different characteristics.

In general, male and female sounds, sound effects and human voices, etc. have different sound sources.

Therefore, it is desirable for a speech synthesis circuit that includes a sound source and a digital filter to have several types of sound sources.
For example, if we consider a case where there are two types of sound sources A and B, if we start speech synthesis by adding a signal to the synthesis start signal while adding a sound source specifying signal to the selection circuit so that sound source A is input to the digital filter, A The voice of person B is synthesized, and then the voice of person B is synthesized by adding a sound source specifying signal to the selection circuit and adding a signal to the synthesis start signal to start voice synthesis. be done. However, with this method, it is necessary to always add a sound source designation signal to the selection circuit. Furthermore, by changing the sound source designation signal added to the selection circuit and adding a signal to the synthesis start signal, the voice of person A is transferred to the voice of person B, so the procedure is one step.First, It can be divided into two stages. The present invention makes it possible to start generating phrases and change the sound source designation through l-step operations without constantly applying a sound source designation signal.

Hereinafter, the present invention will be explained based on illustrated embodiments.

In the drawing, 1 is a voiced sound source ROM (read only memory) which is a sound source that generates a plurality of periodic sound source signals, and 2 is its address decoder, which constitutes selection means. 3 is a noise signal generator that is a sound source that generates a noise-like sound source signal; 4 is a sound source switching unit that selects either the output of the voiced sound source ROMI or the output of the noise signal generator 3; and 5 is a digital sound source. Filter, 6 is DA converter,
7 is a pitch counter, and 8 is a latch circuit, which constitute a synthesis section.

9 is a sound source designation signal, 10 is a synthesis start control unit, and 11 is a phrase start signal.

Also, 12 is a parameter register, 13 is a parameter R
OM, 14 is a decoding ROM, and 15 is an interpolation circuit, which constitute a parameter generation section that sequentially inputs audio parameters to the synthesis section in time series. Here, the sound source designation signal 9 is latched by the latch circuit 8 in synchronization with the phrase start signal 11. That is, the phrase start signal 11 is applied to the synthesis start control section 10, and the synthesis start control section 10 controls the start of the operation of the parameter generation section to determine the start of synthesis. At the same time, the synthesis start control section 10 generates a load signal for the latch circuit 8. The output of the latch circuit 8 remains "constant" until the next new phrase start signal 11 is applied and a new phrase begins to occur. Then, the output of the latch circuit 8 is applied to the address decoder 2,
Either of the two types of voiced sound source signals in the voiced sound source ROM1 is addressed. As a result, two different types of voices can be generated in response to two types of voiced sound sources. If the sound source designation signal 9 is changed every time the phrase start signal 11 is input, a different sound source designation signal will be latched in the latch circuit 8 each time, and once it is latched, the supply of the sound source designation signal 9 will be stopped. I don't mind.

Therefore, the procedure is completed in one step, and there is no need to constantly apply the sound source designation signal 9. The voiced sound source is a periodic sound source, and several types of its patterns are stored in the voiced sound source ROM1.

Which pattern is to be read out is specified by the output of the latch circuit 8, and is decoded by the address decoder 2. Which word in one pattern is to be read is repeatedly designated by a pitch counter 7 in pitch cycles.

The unvoiced sound source is generated by a noise signal generator 3, which may be constant regardless of the type of sound. Note that as the digital filter 5, for example, a Lattice filter based on the PARCOR method is generally used. Also,
In the parameter ROM13, one set of each parameter of amplitude, pitch, and reflection coefficient according to the PARCOR method is stored for every 20 ms frame length. These parameters are taken out in chronological order and stored in the decoding ROM14.
For the purpose of improving sound quality, the interpolation circuit 15 interpolates the value of the same type of parameter between frames, for example, every 2.5 ms, and inputs it to the pitch counter 7 as a pitch parameter. It is transferred to the register 12 as amplitude and reflection coefficient parameters. As is clear from the above description, the present invention eliminates the need to constantly apply a sound source designation signal by capturing and holding the sound source designation signal in a latch circuit using a phrase start signal in a sound source circuit having a plurality of voiced sound sources. Also,
This system has an excellent feature of being able to instantly start generating a phrase and change the sound source designation in a single step.

[Brief explanation of the drawing]

The drawing is a plotter diagram of a main part of an embodiment of the present invention. 1...ROM for voiced sound source, 2...Address decoder, 3...Noise signal generator, 4...
....Sound source switching section, 5 ....Digital filter, 7 ....Pitch counter, 8 ....Latch circuit, 9 ....Sound source specification signal, 10・・・・・・
-Synthesis start control unit, 11...Phrase start signal, 12
...Parameter register, 13 ...Parameter ROM, 14 ...Decoding RO
M, 15... Interpolation circuit.

Claims (1)

[Claims] 1 a first sound source that generates a plurality of periodic sound source signals; a second sound source that generates a noisy sound source signal;
A synthesis section includes a sound source switching section that selects the output of one of the sound sources to obtain the output, a filter section that amplifies the output of the sound source switching section and filters the frequency in a time-varying manner, and the synthesis section has an audio parameter. a parameter generation section that sequentially inputs the parameters in chronological order, and a synthesis start control section that receives a start signal and controls the start of operation of the parameter generation section, and
The synthesis unit includes selection means for selecting any one of the plurality of periodic sound source signals and supplying the selected one to the sound source switching unit;
A sound generation device comprising a latch circuit to which a sound source designation signal is input, an output signal of the synthesis start control section is input as a load signal, and supplies an output signal to the selection means.