JP3219113B2 - Small sound pickup playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio signal used for a two-way audio communication such as a teleconference, and the like.
The present invention relates to a small-sized sound collecting and reproducing apparatus that converts an electric acoustic signal into an acoustic signal.

[0002]

2. Description of the Related Art Conventionally, in a two-way audio communication such as a teleconference, a conference is often held by a large number of people at one time. Therefore, a speaker and a microphone installed on a desk are used to reproduce an audio signal and collect sound. Type of acoustic equipment is used. On the other hand, with the miniaturization of various devices, desktop-type two-way audio communication devices are being developed. However, this desktop-type two-way audio communication device is not an open-type audio facility as described above, but a closed space. There is a demand for the development of closed-area acoustic equipment.

[0003] As closed-area acoustic equipment, insert-type and intra-concha-type earphones and headphones that are used by inserting them into the ear cavity have been developed. Is being done. In addition, a device that collects only a desired acoustic signal using a plurality of microphones has been developed (for example, Yutaka Kaneda: “Adaptive Microphone Array” Transactions of the Institute of Electronics, Information and Communication Engineers, Vol. J75-B-II No. 11).
pp. 742-748 1992.11).

[0004]

SUMMARY OF THE INVENTION In a small-sized sound collecting and reproducing apparatus such as an earphone or a headphone for reproducing an acoustic signal provided with a sound collecting microphone which has been conventionally developed, the sound collecting and reproducing apparatus is used to reduce the size and weight. The microphone is close to or integrated with the playback unit and is installed near the ear,
There is a first problem that sound quality is deteriorated as compared with sound pickup in front of the oral cavity.

This will be described with reference to the drawings. FIG. 10 shows a frequency characteristic of an audio signal when sound is collected in front of the oral cavity. When sound is collected in front of the oral cavity, frequency components are distributed over the entire voice band. In contrast, FIG. 11 shows frequency characteristics when sound is collected near the ear. In this case, the attenuation is large on the high frequency side of the audio band, and the sound quality is degraded. This is described, for example, in (HK Dann, DW Farnsw).
orth: Exploration of Press
ure Field around the Human
Head During Speech, J.M. A.
S. A. , Vol. 10, p. 184 1939).

In the case of performing two-way acoustic communication, the reproducing section and the sound collecting section are very close to each other.
There is a second problem that howling or the like is likely to occur when the device is worn on the ear, which may adversely affect the eardrum. In addition, the sound pickup unit used in the apparatus uses a unidirectional or omnidirectional microphone unit in order to reduce the size and weight, and there is a third problem that unnecessary external noise is easily picked up. is there.

An object of the present invention is to provide a good reproduction / sound collecting function for two-way sound communication in a closed-area sound facility.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a small sound collecting and reproducing apparatus comprising a sound collecting section for two-way sound communication and a small sound converting section for reproducing a sound signal. It is characterized in that a more natural sound signal is obtained by performing a correction corresponding to a frequency characteristic in front of the oral cavity on an electroacoustic signal collected by using an acoustic equalizer for adjusting a frequency characteristic.

Also, howling that can occur when the device is mounted on the ear shell by installing a switch unit for temporarily attenuating or cutting off the electric sound signal from the sound pickup unit or the electric sound signal to the small sound reproduction unit. Is reduced. Furthermore, by installing a plurality of sound collection units and signal processing units in the device, noise is prevented from being mixed in from devices other than the desired sound source.

[0010]

1 and 2 are external views of a small-sized sound pickup / reproducing apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a small sound reproducing unit to be inserted into the ear cavity, 2 denotes a sound collecting unit for collecting sound signals, and 3 denotes a housing for housing these. FIG. 1 shows a sound collecting section 2 installed integrally with a conventional small-sized sound reproducing apparatus, and FIG. 2 shows a sound collecting section 2 installed outside to improve sound collecting characteristics.

FIG. 3 is a functional block diagram of the present invention.
1 and 2 are denoted by the same reference numerals. Reference numeral 4 shown in FIG. 3 denotes an acoustic equalizer unit that corrects the frequency characteristics of the acoustic signal collected by the sound collection unit 2. The acoustic equalizer unit 4 is a device capable of dividing an acoustic signal into a plurality of frequency bands and individually correcting and adjusting respective gains.

FIG. 3 shows an example in which the acoustic equalizer 4 is installed outside the housing 3. However, the acoustic equalizer 4 can be installed in the housing 3 as shown in FIG. FIG. 5 shows a case where the present invention is applied to headphones. 5
Is a headphone unit. Although the sound equalizer units 4 are provided on the left and right sides, the sound equalizer units 4 may be provided outside the housing 3 after performing addition processing of signals from the left and right sound pickup units 2 and the like.

FIGS. 6 and 7 show an embodiment of a small-sized sound collecting and reproducing apparatus proposed in claim 2. FIG. In the figure, reference numerals 6 and 7 denote switch units for temporarily attenuating or cutting off the electric sound signal from the sound pickup unit 2 or the electric sound signal supplied to the small sound reproduction unit 1. The example of FIG. 6 shows a case where a switch unit 6 which exerts an effect by external pressure is used. As a switch that exerts an effect by external pressure, for example, a push button switch or a switch using a piezoelectric conversion element can be used. When the earphone or the headphone is worn on the ear, the switch unit 6 is pressed to temporarily cut off or sufficiently attenuate the sound conversion output of the sound pickup unit 2 or the sound signal given to the small sound reproduction unit 1, and howling. The sound conversion output of the sound pickup unit 2 is returned to a normal value by releasing the operating force of the switch unit 6 after the earphone is attached to the ear in a state where the occurrence of the sound is suppressed.
Make calls available.

When the earphones and headphones are worn on the ears, the space between the small sound reproducing unit 1 and the sound collecting unit 2 is shielded by an ear cavity, an ear shell, and the like, and howling is suppressed. The example of FIG. 7 shows a case where the switch unit 7 that provides the effect by external light is used. That is, when the earphone or the headphone is not attached to the ear using the photoelectric conversion element as the switch element, the light OP enters the switch unit 7,
The resistance value of the photoelectric conversion element is kept small. When the photoelectric conversion element is maintained at a small resistance value, the acoustic conversion output of the sound pickup unit 2 or the acoustic signal given to the small acoustic reproduction unit 1 is bypassed in a large amount to control the gain of the acoustic coupling loop to be narrowed. , To suppress howling. When the earphones or headphones are attached to the ears, the light OP to the switch unit 7
Is shielded, the resistance value of the switch unit 7 is increased, and the amount of sound conversion output of the sound pickup unit 2 or the sound signal given to the small sound reproduction unit 1 is reduced, thereby reducing the gain of the sound signal system. Return to normal value. When the switch unit 7 constituted by the photoelectric conversion elements is used as described above, a state in which a call can be made according to the detachment of the earphone or the headphone,
It is possible to automatically switch to the howling suppression state.

FIGS. 8 and 9 show an embodiment of a small-sized sound collecting and reproducing apparatus proposed in claim 3. FIG. FIG. 8 shows an embodiment of the external structure, and FIG. 9 shows an electrical embodiment. In this embodiment, a plurality of (three in the figure) sound collecting sections 2 are installed on the outer periphery of the housing 3 of the headphone unit 5, and the plurality of sound collecting sections 2 are provided.
, And receives a desired signal (for example, a voice sound signal of a person wearing headphones in this case) from among them by the signal processing unit 8 (see FIG. 9). And unnecessary signals (noise) from the outside can be removed. Regarding the internal processing of the signal processing unit 8, for example, Yutaka Kanada “Adaptive Microphone Array” (Transactions of the Institute of Electronics, Information and Communication Engineers, Vol. J.
75-B-IINO. 11 P742-748 199
2, 11).

[0016]

As described above, by using the present invention, more natural sound signal collection and reproduction can be achieved in closed area type bidirectional audio communication without using a speaker and a microphone. In addition, microphones that were fixed on the desk for collecting audio and audio signals are no longer required, so that sound can be collected in a wide range and the work space on the desk can be eliminated. Become.

Further, since howling or the like that may occur when the device is mounted on the ear can be reduced, it is possible to construct a device that is more human-friendly. Furthermore, since unnecessary external sound signals can be prevented from being reduced,
Better two-way acoustic communication becomes possible. Therefore, by using the present invention, natural and higher quality two-way acoustic communication that is closer to face-to-face conversation becomes possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an external structure of a small sound collecting and reproducing apparatus according to the present invention.

FIG. 2 is a perspective view showing another example of the external structure of the small sound collecting and reproducing apparatus according to the present invention.

FIG. 3 is a connection diagram showing an example of an electrical implementation structure of the small-sized sound collection / reproduction device proposed in claim 1 of the present application.

FIG. 4 is a connection diagram showing another example of the electrical implementation structure of the small-sized sound collection / reproduction device proposed in claim 1 of the present application.

FIG. 5 is a connection diagram showing still another example of the electrical implementation structure of the small-sized sound collection / reproduction device proposed in claim 1 of the present application.

FIG. 6 is a connection diagram showing an example of an electrical implementation structure of the small-sized sound collection / reproduction device proposed in claim 2 of the present application.

FIG. 7 is a connection diagram showing another example of the electrical implementation structure of the small-sized sound collection / reproduction device proposed in claim 2 of the present application.

FIG. 8 is a perspective view showing an example of the external structure of the small-sized sound collection / reproduction device proposed in claim 3 of the present application.

FIG. 9 is a connection diagram showing an example of the electrical implementation structure of the small-sized sound collection / reproduction device proposed in claim 3 of the present application.

FIG. 10 is a diagram for explaining a conventional technique.

FIG. 11 is a view for explaining inconvenience of the conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small sound reproduction part 2 Sound collection part 3 Housing 4 Sound equalizer part 5 Headphone unit 6 Switch part 8 Signal processing part

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 1/10 101 H04M 3/56 H04R 1/10 104 H04R 3/00 320

Claims (3)

(57) [Claims] 1. A small-sized sound pickup / reproduction device in which a sound pickup unit and a small sound reproduction unit are housed in a housing mounted close to an ear, wherein the sound pickup unit is disposed near an ear. Sound frequency characteristics equivalent to picking up the sound signal in front of the oral cavity
Small sound pickup reproducing apparatus characterized in that a sound equalizer is adjusted to. 2. The small-sized sound collecting and reproducing apparatus according to claim 1, wherein
A small-sized sound collecting and reproducing apparatus provided with a switch unit for attenuating or cutting off an electric sound signal from a sound collecting unit or an electric sound signal to a small-sized sound reproducing unit when the housing is not attached to an ear. . 3. The small-sized sound collecting and reproducing apparatus according to claim 1, wherein
A small-sized sound collecting and reproducing apparatus comprising: a plurality of sound collecting units; and a signal processing unit for extracting a desired sound signal from the sound signals collected by the plurality of sound collecting units.