JPH0396100A - Sound field varying device - Google Patents

Abstract

PURPOSE:To perform the reproduction of a sound field changing successively in real time and without generating a noise by performing an arithmetic processing from a signal stored in a storage means and a signal outputted from a signal processing means with a signal switching means when working procedure is changed. CONSTITUTION:When sound field data is switched i.e., the working procedure is switched, a system control means 6 changes the content of a working instruction means 4 which instructs the working method of the signal processing means 2 to the working procedure so as to realize the next sound field. Also, simultaneously, such control that a change-over switch 16 can be connected to a second storage means 15 side. At this time, the signal switching means 5 performs such computation that the signal can be switched smoothly by using the signal processed with the signal processing means 2 with the oldest data stored in a first storage means 3 and new working procedure. In such a way, it is possible to change the sound field successively without generating the noise due to the disconnection of the signal when switching.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sound field variable device for reproducing the sound field of a hall or the like. Conventional technology In recent years, sound field reproduction has attracted attention in audio technology.
Sound field reproduction devices that can reproduce sound fields such as halls have been developed. Figure 2 is a diagram showing the structure of a conventional sound field reproduction device. In FIG. 2, 8 is a signal input means for inputting an audio signal converted into a digital signal, 9 is a signal processing means for processing the signal by delaying and feeding back the input digital signal in a predetermined procedure, and 10 is a signal processing means for processing the signal. 11 is a system control means for changing the contents of the processing instruction means 10; and 12 is a signal output means for outputting a digital signal output from the signal processing means 9. be.

The operation of the conventional sound field reproduction device configured as described above will be explained. In FIG. 2, the input signal is processed in the signal processing means 9 according to instructions given by the processing instruction means 10, and is converted into a signal suitable for a certain sound field. Next, the output from the signal processing means 9 is converted into an analog signal by connecting it to an external digital-to-analog converter via the signal output means 12.
As shown in the figure, a plurality of power amplifiers 13. Subika 1
By reproducing sound using 4, a desired sound field can be reproduced. For example, as shown in Fig. 4, when the input signal is an impulse signal as shown in (a), the signal processing means 9 delays and adds the signal input to each speaker as shown in Fig. 4 (b). , (C), (d)
, (e), and this impulse train may be representative of early reflections of a certain sound field.

Problems to be Solved by the Invention However, with the above configuration, if the processing instruction procedure is changed in an attempt to continuously change the shape of the reproduced sound field, discontinuity of the signal occurs at the time the procedure is changed. There is a problem in that noise is generated in the output signal, and in order to avoid this problem, a signal blocking means 15 is provided as shown in FIG.
A method has been developed to cut off the signal at the point where noise occurs.

Figure 5 schematically shows the conventional signal state. Fifth
In the figure, (a) shows the output of the signal processing means 9, (b) shows the state of the signal cutoff control signal output by the system control section, and (C) shows the state of the signal cutoff control signal output by the signal output means 12. Indicates the signal status. The wavy arrow indicates the noise generated when the processing procedure is changed.

Although the noise generated when the procedure is switched in this way is removed, there is a problem in that the sound is interrupted when the procedure is switched.

The present invention has been developed in view of the above-mentioned problems, and allows a continuous change in the sound field to be performed smoothly and to reduce the scale of the change. The present invention provides a sound field variable device that continuously realizes movement of the sound field, sense of distance, sense of spaciousness, movement of sound image, etc.

Means for Solving the Problems In order to achieve the above objects, the sound field variable device of the present invention includes a plurality of signal processing means for processing the signals by delaying and feeding back the input digital signals in a predetermined procedure; first and second storage means for storing the output signal of the signal processing means for a certain period of time; processing instruction means for instructing the signal processing means on a signal processing procedure; A changeover switch that switches the signal input to the storage means, and a signal switch that adds the signal stored in the first or second storage means and the output signal from the signal processing means with a certain weight while performing interpolation. and a system control means that changes the instruction content of the processing instruction means and controls the signal switching means and the changeover switch. Effect: With this system, when switching processing procedures, the signal switching means weights the signals stored in the storage means so that they gradually become smaller, and the signals processed by the new processing procedure are weighted so that they gradually become larger. By performing the above steps in sequence, the sound field can be changed continuously without noise caused by signal discontinuity when switching. I can go. EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a hardware block diagram of a sound field variable device according to an embodiment of the present invention. In FIG. 1, 1 is a signal input means for inputting an audio signal converted into a digital signal, 2 is a signal processing means for processing the signal by delaying and feeding back the input digital signal according to a determined procedure, and 4
3 and 15 are first and second storage means for storing the output signals of the signal processing means 2; and 5 is a first storage means when switching the processing procedure. Alternatively, the signal stored in the second storage means 3.15 and the output signal from the signal processing means 2 are interpolated and added with a certain weighting, and a signal is output. 16 is a switch for switching the input signal to the first and second storage means 3.15 when changing the processing procedure; 6 is a signal switching means for outputting the output signal from the storage means 3 and 15 as it is; 6 is a switch for switching the input signal to the first and second storage means 3. System control means changes the contents of the instruction and controls the signal switching means 5 and the changeover switch 16. Reference numeral 7 denotes a signal output means for outputting a digital signal output from the signal switching means 5.

The operation of the sound field variable device configured as described above will be explained below. When a constant sound field is realized, the digital signal input to the signal input means 1 in FIG. The signal is outputted via a 1,000-stage memory 3, a 1,000-stage signal switch 5, and a signal output means 7 to realize a desired sound field. Therefore, the input signal is delayed by a certain amount of time and then output. At this time, the changeover switch 16 is connected to the lth storage means 3 side as shown in the figure.

Next, when switching the sound field data (switching the processing procedure), the system control means 6 converts the contents of the processing instruction means 4, which instructs the processing method of the signal processing means 2, into a processing procedure that realizes the next sound field. Change to

At the same time, the selector switch 16 is switched to the second storage means 1.
Control so that it is on the 5 side. At this time, the signal switching step 5 performs an operation such that the signal is smoothly switched using the oldest data stored in the first storage means 3 and the signal processed by the signal processing means 2 according to the new processing procedure. Do this.

Since the calculation performed by the signal switching means 5 is digital signal processing, the calculation must basically be performed every l sample.

This calculation and processing method will be explained using Fig. 6. In FIG. 6, (a) shows a signal stored in the first storage means 3, and (b) shows a signal newly processed and output by the signal processing means 2. Also, (C) is the first
(d) is a function that gradually becomes smaller and weights the signal stored in the storage means 3, and (d) is a function that gradually becomes larger and weights the signal newly output from the signal processing means 2. It is a function.

First, the signal switching means 5 calls up the oldest signal A5 stored in the first storage means 3, multiplies it by the value Cl shown in FIG. is stored in the second storage means 15, and this signal B1 is further multiplied and added by the value Di shown in FIG. 6(d). This calculation is shown in equation (1).

已1- (A5XC1)+ (B1xD1)・・・・・・
(1) This added signal El is input to the signal output means 7. Do this within the 1+ numbling. At the time of the next sampling, the average value of the second oldest signals A4 and A5 stored in the first memory stage 3 is taken, and
Multiply by the value C2 shown in C). Then, this value, B2 output from the signal processing stage 2, and the second storage means l
6 (d).
) is added to the multiplication result with {1iD2, and the result is output to the signal output means 7. This calculation is shown in equation (2).

At this time, the signal B2 output from the signal processing means 2 is stored next to B1 in the second storage means 15.

E2・(A5+A4)/2+(B 1+82)/2
......(2) At the next sampling, the first
A4 stored in the storage means 3 of is multiplied by C3 shown in FIG. 6(C). Then, this value is added to the multiplication result of B2 output from the signal processing means 2 and D3 shown in FIG. 6(d), and the result is output to the signal output means 7. At this time, the signal B3 output from the signal processing means 2 is stored after B2. E3-A4XC3-1-B2XD3...
(3) When changing the processing procedure as described above, the above-mentioned calculation is repeated using the output signal from the signal processing means 2 and the signal stored in the first memory stage 3, and the first
Until the signal processed by the old processing procedure stored in the memory 3 is exhausted (about 2-5ms according to experimental results)
ec level). When this calculation is completed, the signal stored in the second storage means 15 is output to the signal output means 7. At this time, the signal stored in the second storage stage 15 is Since this is the next signal to the signal on which the previous operation was performed, the signals are connected smoothly. FIG. 7 shows the contents of the first and second storage means 3.15 for each sampling in which calculations are performed.

Next, when switching the processing procedure, the changeover switch 16 is turned to the first storage means 3 side, and the signal switching means 5 outputs the output signal of the signal processing stage 2 and the second storage means 1.
Using the signals stored in 5, the calculations shown above are performed to switch the signals. By performing the above operations alternately each time the sound field is changed, the sound field can be changed continuously without the noise caused by switching due to signal discontinuity. Effects of the Invention As described above, the present invention uses the first and second storage means to smoothly change the signal from the stored signal and the signal output from the signal processing means at the time of signal switching. By performing arithmetic processing in the signal switching means when changing the processing procedure, continuously changing sound field reproduction can be performed in real time without generating noise.

[Brief explanation of drawings]

Fig. 1 is a hardware block diagram of a sound field variable device according to an embodiment of the present invention, Fig. 2 is a hardware block diagram of a conventional sound field variable device, and Fig. 3 is an installation example of the sound field variable device. Composition diagram, Figure 4 is an output signal waveform diagram that reproduces the sound field for the input signal, Figure 5 is a waveform diagram showing the state of the output signal in the conventional sound field variable device, and Figure 6 is the signal used in the present invention. FIG. 7, which is an explanatory diagram of the calculation method in the switching means, is a diagram showing the contents of the first and second storage means in the present invention. 1...Signal input means, 2...Signal processing means, 3...1th storage means, 4...
Processing instruction means, 5... Signal switching means, 6.
...System control means, 7 ... Signal output means, l6 ... Changeover switch, I5 ...
...Second storage means.

Claims (1)

[Claims] a signal input means for inputting an audio signal converted into a digital signal; a signal processing means for processing the signal by delaying and feeding back the input digital signal according to a determined procedure; processing instruction means for instructing a processing procedure, first and second storage means for storing the output of the signal processing means for a certain period of time, and outputting an output signal from the first or second storage means; a signal switching means for interpolating the signal stored in the first or second storage means and the output signal from the signal processing means at the time of switching the processing procedure, adding the signal with a certain weighting, and outputting the resultant signal; a switching means for switching input signals to the first and second storage means when switching the processing procedure; and a system control means for changing the instruction content of the processing instruction means and controlling the signal switching means and the switching means. , and signal output means for outputting the digital signal output from the signal switching means.