JP2526711B2 - Sound image localization device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a sound image localization device that can imitate (simulate) the sense of localization of a musical sound that sounds to a listener (listener) in a specific direction. Regarding

(B) Conventional Technique At present, in stereo devices and the like, the sound level of a musical sound is localized by making different output level ratios of the same musical sound output from a plurality of musical sound output systems. When the number of output channels is 2, the musical sound can be localized two-dimensionally between the two output devices (speakers), and when the number of output channels is 4, the musical sound can be localized more clearly. be able to.

(C) Problem to be Solved by the Invention As described above, in the conventional stereo device, the output level ratio of the left and right channels is controlled to express the sense of localization of the sound image only by the difference in the volume heard by the left and right ears. . However, when a sound source (musical instrument, etc.) is actually placed in a specific direction and distance, the localization of the sound image is not only different in the volume of the musical sound that can be heard by both the left and right ears, but also in the way it resonates and in delicate time. There is a difference in delay. In a conventional stereo device, such a difference could not be expressed, so that there was a drawback that a clear localization feeling as if an actual musical instrument was laid out could not be obtained.

In order to solve this, it is conceivable to install a delay circuit and a filter on both the left and right channels and filter / delay the music signal with filtering characteristics and delay time that match the localization position of the sound image, but the localization position of the music signal is It is difficult to store the filtering characteristics and the delay times in all the various directions that are possible from the viewpoint of the memory capacity.

The present invention provides a sound image localization apparatus capable of realizing sound image localization in all directions with a small storage capacity by obtaining a filtering characteristic and a delay time corresponding to a specified sound image localization direction by interpolation. The purpose is to

(D) Means for Solving the Problems The present invention aims to imitate a processing circuit having a delay circuit, a filter and an amplifier for processing an input music signal, and imitating the transmission of a sounded musical sound to the listener's ear. Of the transmission data including the delay time, the filtering characteristic and the amplification factor of the listener for a plurality of angles with respect to the listener, the localization direction designating means for designating the direction of the musical sound at an arbitrary angle, and the localization direction designating means. The two transmission data sandwiching the specified angle are read out from the table, the delay time of the two transmission data, the filtering characteristic and the amplification factor are respectively interpolated, and the delay time of the angle designated by the localization direction designating means and the filtration are obtained. It is characterized in that a reading means is provided for obtaining the characteristic and the amplification factor and supplying the delay time, the filtering characteristic and the amplification factor to the processing circuit.

(E) Action of the Invention In the sound image localization apparatus of the present invention, the delay circuit, the filter,
By changing the delay time of the amplifier, the filtering characteristic, and the amplification factor, the transmission of musical sound from a specific direction is simulated. That is, there is almost no delay / attenuation from the sound source in the direction close to the ear, and the frequency characteristic is transmitted without change, but the delay time, the attenuation rate, and the high range attenuation become large from the sound source in the direction far from the ear. The transmission data representing such characteristics are stored in advance in a table for a plurality of angles with respect to the listener, and when the angle is input from the localization direction designating means for designating the direction of the musical sound, the transmission data corresponding to this angle is stored in the table. The transmission data stored in the table is obtained by interpolation, and this transmission data is set in the delay circuit, the filter and the amplifier. As a result, only the transmission data for each fixed angle is stored in the table, but the angle can be specified as an arbitrary angle.

(F) Embodiment FIG. 1 is a block diagram showing a schematic configuration of a sound image localization apparatus that is an embodiment of the present invention. In this sound image localization device,
A keyboard 11 and a tone generator circuit 12 are connected as a tone generator for which a sound image is to be localized. The keyboard 11 instructs the tone generator circuit 12 on the pitch, volume and tone color of the musical tone to be generated, and the tone generator circuit 12 forms the musical tone based on this instruction. The formed musical sound is output as it is as a digital signal (quantized signal) to the output processing system of a plurality of channels. This sound image localization device is provided with an output processing system of a plurality of channels (n channels), and each output processing system includes a delay circuit.
It has a filter 20 and an amplifier 21. The delay circuit 19, the filter 20, and the amplifier 21 can set the delay time, the filtering characteristic, and the gain from the outside, respectively.

Generally, the number of channels n is 2 or 4. In the case of 2 channels, two-dimensional localization is possible between the left and right (R / L) channels, and in the case of 4 channels, right front (RF), left front (LF), right back (RR), left back (LR) The sense of localization becomes clearer between channels.

The delay circuit 19, the filter 20, and the amplifier 21 are connected to the delay length table 13,
The parameters (coefficients) from the filter coefficient table 14 and the amplifier coefficient table 15 are input.

As shown in FIG. 2, each table 13, 14, 15 stores a delay time for simulating the direction of a sound source with respect to a person, an LPF (low pass filter) cutoff frequency, and an amplification factor.

These tables 13, 14, 15 and read interpolation circuits 16, 17,
The direction input operation element 10 is connected to 18. The read interpolation circuits 16, 17, 18 read out the data corresponding to the direction designated by the operation of the direction input operator 10 from the respective tables 13, 14, 15. In addition, 0 degrees (front) on the tables 13, 14 and 15
Transmission data is stored in 30 degree increments from, but if a localization direction other than this angle is specified, the read complement circuit
16, 17, 18 calculates the parameter in the specified direction using the parameters of the measurement angles adjacent to the specified direction.
The calculation formula is performed by a known internal division operation.

In the above configuration, in the case of 2 channels, the amplifier 21
If the music signals output from -1, 21-2 are output from a speaker provided right beside the listener in the left-right direction, a clear music localization feeling can be obtained. The output method is not limited to the speaker, and headphones may be applied. Also,
In the case of 4 channels, the speakers may be arranged at the 4 corners, and in the case of 8 channels, the speakers may be arranged above and below the 4 corners. However, it is not limited to these.

Any type of direction input operator 10 may be used. For example, a mouse or a joystick may be used, a function may be given in advance, and the time may be controlled based on the function value output as a variable.

Further, although the sound source is a monaural sound source in the present embodiment, it can be similarly applied to a multi-channel sound source such as a stereo sound source.

Although the present embodiment is configured by hardware,
It may be configured by software using a CPU.

(G) Effect of the Invention As described above, in the sound image localization apparatus of the present invention, the delay circuit,
The delay time of the filter, the amplifier, the filtering characteristic, and the gain are obtained by interpolation based on the transmission data stored for a plurality of angles, so that no matter what angle is specified, the direction in which the musical sound is heard Can be realistically simulated and a clear sound image localization feeling can be realized.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a sound image localization apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing stored contents of a table used in the sound image localization apparatus. 13 …… Delay length table, 14 …… Filter coefficient table, 15 …… Amplifier coefficient table, 16,17,18 …… Read-out interpolation circuit, 19 …… Delay circuit, 20 …… Filter, 21 …… Amplifier.

Claims (1)

(57) [Claims] 1. A delay circuit, a filter and an amplifier,
A processing circuit for processing the input musical sound signal, and transmission data including delay time, filtering characteristics and amplification factor for imitating transmission of the sounded musical sound to the listener's ear, for a plurality of angles with respect to the listener. The stored table, the localization direction designating means for designating the direction of the musical tone at an arbitrary angle, and the two transmission data sandwiching the angle designated by the localization direction designating means are read out from the table, and the two transmission data of the two transmission data are read. The delay time, the filtration characteristic and the amplification rate are interpolated to obtain the delay time, the filtration characteristic and the amplification rate of the angle designated by the localization direction designating means, and the delay time,
A sound image localization apparatus comprising: a reading unit that supplies a filtering characteristic and an amplification factor to the processing circuit.