JPH05199596A - Acoustic field reproducing device - Google Patents

Abstract

PURPOSE:To correctly obtain acoustic image orientation in any direction. CONSTITUTION:A speaker 6 is arranged in the position where an acoustic image should be orientated, and aural transducers 7 and 8 used for microphone as well as earphone are set in right and left ears of a listener 9, and head part transfer characteristics between the input of the speaker 6 and transducers 7 and 8 are calculated by operation parts 10 and 11, and these right and left head part transfer characteristics are set as filter characteristics to filters 14 and 13, and the input signal of an input terminal 12 is allowed to pass these filters 14 and 13, and respective outputs of filters 14 and 13 pass filters 16 and 15, and frequency characteristics of the speaker 6 and transducers 7 and 8 are corrected, and corrected outputs are supplied to transducers 7 and 8 and are heard, and the sound image is localized in the position of the speaker 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is omnidirectional when listening with headphones attached to the ear, or when listening with a speaker reproduction equivalent to listening to headphones (hereinafter, simply referred to as listening to headphones, etc.). The present invention relates to a sound field reproducing apparatus capable of giving a listener a good sense of localization corresponding to a large number of sound sources distributed in the.

[0002]

2. Description of the Related Art In the conventional technique, a standard pseudo head or a stereo signal obtained by convolving an input signal with the head-related transfer characteristics of the listener himself / herself measured in the past was used. When listening to this signal with headphones, when the standard head-related transfer characteristic of the pseudo head was used, the sound image to be localized outside the head was localized inside the head, and good localization was not obtained.

Further, if the listener's own head-related transfer characteristics are used, a good localization feeling can be obtained. However, if the listener is unspecified, the listener's own head-related transfer characteristics cannot be measured in the past. . In other words, human beings hear the sound from a certain sound source with both ears and determine the direction and position of that sound source. That is, a sense of localization for the sound source is obtained. Therefore, as shown on the left side of FIG. 2, the listener's own head-related transfer characteristic (HRTF) between the sound source and both ears is actually measured, the input signal is convolved with the head-related transfer characteristic, and the signal is transmitted to the ears with headphones. 2B, the sound is localized outside the head of the listener as shown in FIG. 2B, and a good sense of localization is obtained. However, the sound source of the reproduced signal is localized in the listener's head as shown in FIG. 2A even if the head-related transfer characteristics measured using the standardized pseudo head or the head-related transfer characteristics of another person are used. However, a good localization feeling cannot be obtained.

Further, in the conventional measurement of the head-related transmission characteristic of an individual, the measurer inserts a small microphone into the listener's ear to perform measurement. In this case, the positions of the microphone and the headphone are different and the measurement accuracy is low. Therefore, it has been difficult to give a good sense of localization to an unspecified number of listeners.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to automatically measure the head-related transfer characteristics of individual listeners, and to cope with a large number of sound sources distributed in all directions when the listener listens with headphones. Even more, it is an object of the present invention to provide a sound field reproducing device capable of giving a listener a good sense of localization.

[0006]

According to the present invention, a speaker which can be arranged at a position where a sound image is to be localized,
A pair of in-ear type microphone and earphone combined transducers, which should be attached to the left and right ears of the listener, respectively, are prepared.
Using these, the head-related transfer characteristics between the speaker and both ears of the listener are measured by the measurement unit from the input of the speaker and the output of the in-ear type microphone / earphone combined converter, and the measured head is measured. The transfer characteristics are set in the filter section, and the input signal is supplied to the filter section.The switch side switches the output side of the filter section and the input side of the measuring section to the in-ear microphone / earphone converter. Connected. Since the frequency characteristics of the speaker and the in-ear microphone / earphone combined converter are usually not flat, the frequency characteristics are corrected and a signal is supplied to the in-ear microphone / earphone combined converter.

[0007]

With this structure, the sound field reproducing device uses the in-ear type microphone / earphone combined converter,
Automatically and accurately measure the head-related characteristics of each listener,
The measured head-related transfer characteristics of the listener are convoluted with the input signal, and the listener listens to the signal with the in-ear microphone / microphone / earphone combined transducer, so that unspecified listeners are distributed in all directions. It is possible to obtain a good sense of localization corresponding to the sound source.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an embodiment of the present invention for reproducing a good sense of localization corresponding to one sound source. The sound field reproducing device 1 of the present invention comprises a measuring unit 2 for measuring the head-related transfer characteristics of the listener himself, a filter unit 3 for convolving the measured head-related transfer characteristics with an input signal, a speaker and an in-ear microphone / earphone converter. It is composed of a block 4 for correcting the frequency characteristic and a switcher 5 when the in-ear microphone / earphone / combined converter is used as a microphone or an earphone.

In the measuring unit 2 for measuring the head-related transfer characteristics of the listener himself, the sound is radiated from the speaker 6 assuming a sound source, that is, the speaker 6 arranged at the position where the sound image should be localized. The sound from the speaker 6 is received by the in-ear type microphone / earphone combined converters 7 and 8 mounted on the right and left ears of the listener 9, respectively. Each output of these in-ear type microphone / earphone dual-purpose converters 7 and 8 is a switching device 5.
Then, in the measurement unit 2, a calculation unit 10 for measuring the head-related transfer characteristics between the speaker 6 and the right ear, and a calculation unit 11 for measuring the head-related transfer characteristics between the speaker 6 and the left ear. Sent to each. The head-related transfer characteristic between the speaker 6 and the right ear obtained by the calculation unit 10 is calculated as a coefficient of the filter 14 in the filter unit 3 for convolving the input signal from the input terminal 12 to be localized. The head-related transfer characteristic between the speaker 6 and the left ear obtained in step 1 is set as the coefficient of the filter 13 for convolution with the input signal of the terminal 12.

The signal convoluted with the head-related transfer characteristic between the speaker and the left ear by the filter 13 is a correction for correcting the frequency characteristic of the speaker 6 and the in-ear microphone / earphone converter 8 for the left ear. A signal obtained by convoluting the head-related transfer characteristics between the speaker and the right ear by the filter 14 as a left signal through the filter 15 in the section 4 is a speaker 6 and an in-ear microphone earphone / converter for the right ear. As a right signal through the filter 16 for correcting the frequency characteristic of 9,
Each is supplied from the switch 5 to the in-ear microphone / earphone / converter 8 for the left ear and to the in-ear microphone / earphone / converter 7 for the right ear. The correction unit 4 may be provided before the filter unit 3.

FIG. 3 shows the loci of sound image localization obtained by the conventional device and the device of the present invention. With the conventional device, sound image localization cannot be obtained in the front, but with the device of the present invention, sound image localization can be obtained in all directions, demonstrating the effectiveness of the present invention. This example shows that a listener can be given a good sense of localization for one sound source. For a large number of sound sources, in FIG. 1, the head-related transfer characteristics are measured for each of the sound sources in the same manner as in the case of a single sound source, and input is made for each input signal according to the number of sound sources. A terminal is provided, and the head-related transfer characteristics between the speaker and the left ear and the head-related transfer characteristics between the speaker and the right ear corresponding to each sound source are supplied to the convolution filter, and the outputs of these filters are fed to the right signal. Signals and left signals may be added as left signals.

[0012]

As described above, the sound field reproducing apparatus of the present invention automatically and accurately measures the head-related transfer characteristics of the listener using the in-ear type microphone / earphone combined transducer. A listener's head-related transfer characteristic is convoluted with the input signal, and the listener listens to it with an in-ear microphone / earphone converter, which supports a large number of sound sources distributed in all directions to unspecified listeners. A good localization feeling can be imparted. This headphone is of the in-ear type and is located at the same position as the in-ear type microphone at the time of measuring the head-related transfer characteristic, so that the head-related transfer characteristic can be accurately measured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a difference between head-related transfer characteristics and headphone reproduction.

FIG. 3 is a diagram showing a sound image localization feeling.

Claims (1)

[Claims] 1. A speaker arranged at a position where a listener should be localized for a sound image, a pair of in-ear type microphone / earphone dual-purpose converters to be attached to both ears of the listener, and the speaker. From the signal and the outputs of the pair of in-ear microphone / earphone combined transducers mounted on the listener's left and right ears, the head-related transfer characteristics between the listener's both ears and the speaker are shown. The measuring section to be measured, the filter section to which the measured head-related transfer characteristics are set, and the input signal is input, the in-ear microphone / earphone / combined converter on the input side of the measuring section, and on the filter section. A sound field reproducing device having a switcher for switching and connecting to the output side.