JPH064400Y2 - Voice analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a voice analysis device, and more particularly to improving the efficiency of its memory and its access mechanism.

(B) Conventional Technology In a conventional data processing apparatus suitable for audio signal processing, a memory is provided as is clear from the configuration of the signal processor shown in, for example, the magazine "Interface", April 1986, pages 253 to 254. And the size of the address space pointed to by the address pointer of the memory were the same. Therefore, when performing the voice analysis of the PARCOR method using these processing devices, if the data of the even function such as the Hamming window is continuously accessed,
It was necessary to hold all the data of the even function or perform address control by software.

(C) Problems to be solved by the invention When the data of the Hamming window of the even function for the analysis of each frame of the voice signal is held in the conventional voice analysis device, all the function data of the function are stored in the memory. It was necessary to hold. However, if the even function period is T, the even function data becomes symmetrical with the half cycle 1 / 2T as a boundary. Therefore, in the conventional data processing device, two identical data must be held in order to hold the even function, which causes a problem of increasing the memory capacity. In addition, if the data held in the memory is 1/2 cycle,
There is a problem that it is necessary to judge whether the even function has 1/2 cycle.

(D) Means for solving the problem In the memory access mechanism in the speech analysis apparatus of the present invention, the address generation unit for addressing the memory holding 1/2 cycle of the window function of the even function such as the Hamming window The address space in is set to double the size of the actual memory space, and the address after the exclusive OR of the most significant bit of the address generator and the other bits is used as the address of the memory. Is.

(E) Operation According to the memory access mechanism in the speech analysis apparatus of the present invention, the scale of the memory for holding the data of the even function of the period T can be reduced to half that of the conventional one. In addition, even if compared with the method of holding the data for 1/2 cycle of the even function and judging whether or not the loop point is accessed, the judgment by software is unnecessary, so the load on the software is reduced. It is possible to speed up.

(F) Embodiment FIG. 1 shows the configuration of an embodiment of the memory access mechanism in the speech analyzer of the present invention. In the figure, (1) is a control unit that controls the entire data processing apparatus, and (3) is a window function memory that holds data for 1/2 cycle of a time window function consisting of an even function of the cycle T. , (4) are voice memories storing voice signals. (5) is a window function memory address counter for designating the address of the window function memory (3), and address control is performed by an instruction from the control section (1). Further, (6) is an exclusive OR circuit, for example, a 7-bit exclusive OR of the most significant bit and other bits in the 8-bit address generated by the window function memory address counter (5). Window data memory (3)
Specify as the actual address for. (7) is an address counter for the voice memory (4) and generates an address for this memory (4). FIG. 2 shows a Hamming window of an even function that is often used as a time window. This Hamming window w (n) is expressed by the following equation.

w (n) = (0.54-0.46cos (2πn / N)) ... At this time, N represents the total number of window functions for one period. The value of this Hamming window is symmetric about n = N / 2, as is apparent from FIG.

Next, the operation will be described.

From the beginning of the Hamming window function shown in FIG. 2, N / 2 pieces of data are held in the window function memory (1). This is the third
It is shown in Figure (a). An input audio signal sequence v (n) for applying a Hamming window is input to the memory (4). In the calculation unit (2), the input signal v is obtained by multiplying v (n) held in the voice memory (4) by the Hamming window function w (n) held in the window function memory (3).
Compute the (n) weighted signal v (n). This is shown in the following equation.

v (n) ＝ w (n) ・ v (n) …… At this time, the voice memory (4) that holds the input signal v (n)
Address counter (7) for and window counter memory (3) holding the Hamming window function (5)
Indicate the same address. Therefore, these counters (5) and (7) may be common. Now when N = 256, both address counters (5) (7) become 8 bits,
v (n) is sequentially calculated from n = 1 to 256. n =
Address counter from 1 to N / 2, ie 128
(5), the 7-bit address for the window function memory (3) indicated by the exclusive OR circuit (6) is equal to n. The address movement for this memory (3) at this time is shown in FIG.
It is shown by the solid line in (a). This corresponds to the left half of FIG. That is, from n = N / 2 + 1 (= 129), N
Window function memory address counter in section (= 256)
The address indicated by (5) increases from n = N / 2 + 1 (= 129) to N (= 256), similar to the address of the audio memory address counter (7) for the audio memory (4). However, since the 7-bit address for the window function memory (3) indicated by the exclusive OR circuit (6) takes the exclusive OR of the most significant bit and the other bits, conversely from N (= 128) to 1 It gradually decreases. The movement of the address with respect to the memory (3) at this time is shown by a dotted arrow in FIG. This corresponds to the right half of FIG. Although this series of address movements for the memory (3) only access the window function memory (3) having the N / 2 address as shown in FIG. As shown in FIG. 3 (b), it operates as if the memory (3) at the N address was accessed, and the Hamming window function w is applied to the input signal sequence v (n).
The calculation unit calculates the weighted signal sequence v (n) multiplied by (n).
Performed by (2).

(G) Effect of the device The memory access mechanism in the speech analyzer of the present invention performs an exclusive OR of the most significant bit of the address and other bits when continuously accessing even function data such as a Hamming window. Only by taking the necessary amount, the required memory capacity can be reduced by half without performing software control, and the circuit scale can be reduced and the control can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram of the memory access mechanism of the speech analyzer of the present invention. FIG. 2 is a diagram showing values of the Hamming window function.
FIG. 3 is a memory address change diagram. (3) …… Window function memory, (5) …… Window function memory address counter, (6) …… Exclusive OR circuit.

Claims (1)

[Scope of utility model registration request] 1. A voice analysis device for analyzing a voice signal by applying an analysis time window to an input voice signal, wherein a window of N / 2 address storing a half cycle of the analysis time window consisting of an even function of N samples. The function memory, the address counter that produces a count value of m bits (2 ^m = N), and the exclusive OR of the most significant bit of the value of the address counter and another bit, m-1 bit ( A speech analysis apparatus having a memory addressing mechanism comprising an exclusive OR circuit for addressing the window function memory by obtaining a count value of 2 ^m-1 = N / 2).