WO1991011080A1

WO1991011080A1 - Apparatus for reproducing acoustic signals

Info

Publication number: WO1991011080A1
Application number: PCT/JP1991/000057
Authority: WO
Inventors: Kiyofumi Inanaga; Hiroyuki Sogawa; Yasuhiro Iida; Susumu Yabe
Original assignee: Sony Corporation
Priority date: 1990-01-19
Filing date: 1991-01-18
Publication date: 1991-07-25
Also published as: DE69132430T2; EP0664660A3; DE69132430D1; EP0664660A2; DE69120150T2; CA2048686C; EP0464217B1; DE69120150D1; EP0464217A4; KR920702175A; EP0664660B1; CA2048686A1; EP0464217A1

Abstract

An apparatus for binaurally reproducing acoustic signals using a headphone device. In the acoustic signal reproducing apparatus, a memory means stores information about transfer characteristics of the path from an imaginary source of sound to both ears of a listener in at least one quadrant around the listener. The transfer characteristics information stored in the memory means is used to form transfer characteristics information at the angular position of the head. The information thus formed is represented by the outputs of detecting means, and acoustic signals of the right and left channels are processed by acoustic signal processing means. In the acoustic signal reproducing apparatus, furthermore, at least two pieces of transfer characteristics information near the angular position of the head of the listener are read out from the memory means, and acoustic signals of the right and left channels are processed by acoustic signal processing means based on transfer characteristics information at the angular position of the head found by interpolation by the interpolation calculation means. Even when the listener moves, the acoustic signal reproducing apparatus maintains proper binaural reproduction without causing the imaginary source of sound to move owing to the use of the headphone device.

Description

Description Acoustic signal reproduction device Technical field

The present invention relates to an audio signal reproducing device for performing binaural reproduction of an audio signal using a headphone device. Background technology Conventionally, as in a headphone device that reproduces an acoustic signal using a headphone unit, a pair of heads that are supported near the auricles by being attached to the listener's head when worn on the listener's head A binaural method is known as a method for improving the sense of direction of a sound image, the sense of out-of-head localization, and the like when reproducing an audio signal using a headphone unit.

A sound reproduction system employing this binaural method, for example, as described in Japanese Patent Publication No. 53-2833, uses a predetermined signal in advance for a sound signal reproduced by a headphone device. Processing o

Here, the sense of direction of the sound image, the sense of out-of-head localization, and the like are determined by the volume difference, time difference, phase difference, and the like of the sounds heard by the left ear and the right ear.

The above-mentioned signal processing means, for example, that when sound is reproduced by a speech device arranged apart from the listener, the distance from the sound source, ie, the speech device, to the left and right ears of the listener and the head of the listener are different. The acoustic effect produced by reflection and diffraction in the vicinity and the equivalent acoustic effect This is the signal processing that occurs in the more reproduced audio output. Such signal processing is performed by, for example, a process of convoluting and integrating an impulse response corresponding to the above-described acoustic effect into acoustic signals for the left ear and the right ear.

By the way, when sound reproduction is performed by a speaker device placed away from the listener, the absolute position of the sound image does not change even if the listener moves or rotates the head. The relative direction and position of the sound image perceived by the user changes. On the other hand, when sound reproduction is performed by the binaural method using a headphone device, when the listener rotates the head, the headphone device is also rotated together with the head. The relative direction and position of the sound image felt by the listener do not change.

When performing binaural reconstruction using a headphone device in this way, a sound field is formed in the listener's head due to the difference in the displacement state of the sound image with respect to the direction change of the listener's head. It is difficult to localize the sound image in front of the listener, and the sound image in front of the sound image tends to rise.

Therefore, conventionally, as described in Japanese Patent Application Laid-Open No. 422-227 and Japanese Patent Publication No. 54-192422, a change in the direction of the listener's head is detected, and this detection is performed. By changing the state of the signal processing based on the result, an audio signal reproduction system has been proposed in which a headphone device can obtain a good sense of forward localization. In such an audio signal reproducing system, a direction detecting device such as a so-called jay mouth compass or a magnetic needle is provided on the listener's head. Then, based on the detection result of the direction detection device, the speaker device arranged to be separated from the listener so as to control the level adjustment circuit, the delay circuit, and the like for processing the audio signal. It is intended to obtain a sound field feeling similar to that of sound reproduction by a computer.

By the way, in a conventional binaural reproduction system in which a headphone device is provided with a direction detection device using a gyro compass or the like as described above, it is necessary to control the content of signal processing applied to an acoustic signal in accordance with a change in the direction of the listener's head. Thus, a good sound image localization feeling can be obtained.

However, in order to control the content of the signal processing applied to the acoustic signal in accordance with the change in the direction of the listener's head, the impulse response corresponding to the acoustic effect given to the acoustic signals for the left and right ears, The transfer characteristics are measured in advance for each predetermined angle, and the transfer characteristic information of the enormous amount of information is stored in the storage means. Processing must be performed on the audio signal in real time.

Accordingly, the present invention has been made in view of the above-described conventional situation, and has been made in consideration of the above-described conventional situation. The amount of information of transfer characteristic information from a virtual sound source to a listener's ear, which is necessary for performing binaural reproduction of an audio signal using a headphone device, With a simple configuration using storage means with a small storage capacity, the headphone device does not move the virtual sound source position even when the listener moves, providing an extremely natural sound image localization feeling. It is an object of the present invention to provide an acoustic signal reproducing apparatus capable of performing the obtained binaural reproduction. Disclosure of the invention

The sound signal reproducing apparatus according to the present invention includes: a detecting unit configured to detect a rotation angle position corresponding to a movement of a listener's head with respect to a virtual sound source; and at least one quadrant of the rotation angle position on the listener's head. In which the transfer characteristic information indicating the transfer characteristic from the virtual sound source to the listener's both ears is stored. Forming transmission characteristic information at the head rotation angle position indicated by the detection output by the detection means based on the storage means and the transmission characteristic information of at least one quadrant stored in the storage means; Sound signal processing means for processing the input sound signal of the channel and the input sound signal of the right channel, respectively; and the headphone device reproduces the sound signal passed through the sound signal processing means.

Further, the acoustic signal reproducing device according to the present invention stores transfer characteristic information indicating a transfer characteristic from a virtual sound source to the listener's both ears for each predetermined rotation angle according to the rotation of the listener's head. Storage means, a detection means for detecting a rotation angle position corresponding to the movement of the listener's head with a resolution higher than the predetermined rotation angle, and a rotation angle position near the rotation angle position indicated by the detection output of the detection means. Interpolation means for reading out at least two pieces of transfer characteristic information from the storage means and performing interpolation calculation on the transfer characteristic information at the rotational angle position indicated by the detection output of the detection means, and obtaining by the interpolation calculation means Sound signal processing means for processing an input sound signal of the left channel and an input sound signal of the right channel based on the obtained transfer characteristic information. Play the headphones device acoustic signal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram schematically showing a configuration of an audio signal reproducing device according to the present invention.

FIG. 2 is a time chart schematically showing a state of a signal supplied to an arithmetic unit of the audio signal reproducing apparatus. FIG. 3 is a schematic diagram showing distances and angles calculated by the arithmetic unit of the audio signal reproducing device.

FIG. 4 is a diagram provided for explanation of transfer characteristic information stored in a storage circuit of an arithmetic unit in the audio signal reproducing device.

FIG. 5 is a plan view showing a relative positional relationship between a virtual sound source and a listener for explaining an operation of binaural reproduction by the above-described sound signal reproducing apparatus.

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FIG. 6 is a block diagram schematically showing another configuration of the audio signal reproducing device according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION A sound signal reproducing apparatus according to the present invention is mounted on a listener's head (M) by a headband (1) as in the first embodiment shown in FIG. And a headphone device (10) adapted to support a pair of headphone units (2, 2R) corresponding to the vicinity of the left and right auricles of the listener.

On the headband (1) of the headphone device (10), two sliders (4L) and (4R) having support arms (3D, (3R)) protrudingly formed are slidably mounted. The pair of signal detectors (5L) and (5R) that sense the position detection reference signal sent from the reference signal source (11) are connected to the tip of the support arm (3, (3R)). That is, the pair of signal detectors (5 and (5R)) protrude from the sliders (4L) and (4R) slidably mounted on the headband (1). The headband (1) and the pair of headphone units (2L) and (2), ie, the headphone body are separated from each other by being provided at the tip of the support arms (3L) and (3R). Above the support arm (Supported by (3D, (3R)).

In this embodiment, the reference signal source (11) is composed of an ultrasonic signal source (12) and an ultrasonic speaker (13) for transmitting an ultrasonic signal from the ultrasonic signal source (12) as a reference signal. It is configured. An ultrasonic microphone is used for each of the pair of signal detectors (5L) and (5R) that sense the reference signal.

As shown in FIG. 2A, the ultrasonic wave transmitted from the ultrasonic wave force (13), that is, the reference signal for position detection, is such that a predetermined level of ultrasonic wave intermittently occurs at predetermined time intervals. An ultrasonic wave whose phase can be detected, such as a burst wave transmitted to a computer or a so-called level-modulated wave whose level fluctuates in a predetermined period.

The pair of signal detectors (5L) and (5R) provided in the headphone device (10) are used as reference signals for position detection using ultrasonic waves transmitted from the ultrasonic force (13). Then, each detection signal as shown in B and C of FIG. 2 having a time delay corresponding to the relative positional relationship between the listener and the ultrasonic speed (13) is output.

The pair of signal detectors (5L) and (510 are the support arms (3L) and (3L) that protrude from the sliders (4L) and (4R) slidably mounted on the headband (1). 3R), the headband (1) and a pair of headphone units (2L), (2R), that is, the headphone body is mounted on the listener's head. It is supported by the support arms (3L) and (3R) at a position away from the main body, so even if the listener moves or turns his / her head, it will be hidden behind the listener's head. Without this, the ultrasonic wave transmitted from the ultrasonic speed (13) can be sensed extremely well, and the reference signal for position detection can be detected stably and accurately. The pair of signal detectors (5L) and (5R) slide the sliders () and (4R) along the headband (1) to detect the reference signal for position detection. It can be adjusted to the optimal position. For example, the headphone unit (2L), which is attached to the listener's head (M) by the headband (1) and supported in the vicinity of the left and right auricles of the listener, The position of 2R) depends on the shape and size of the listener's head (M), and there are individual differences, so the pair of headphone units (2L) and (2R) correspond to the positions of the headphone unit (2R). Adjust the positions of the signal detectors (5) and (5R).

Each detection signal obtained by these signal detectors (5L) and (5R) is supplied to an operation i o device (14). · The arithmetic unit (14) is provided with first and second edge detection circuits (15) to which respective detection signals of the reference signal for position detection are supplied by the signal detectors (5L) and (5R). ), (16) and a third edge detection circuit (17) to which the ultrasonic signal from the ultrasonic signal source (12), that is, the reference signal for position detection is supplied.

] 5 f.

The first and second edge detection circuits (15) and (16) detect each rising edge of each detection signal by each of the signal detectors (5L) and (5R) and correspond to the rising edge. Each pulse signal as shown in D and E in Fig. 2 is output. Each pulse signal obtained from the first and second edge detection circuits (15) and (16) is supplied to a distance calculation circuit (18) and a binaural time difference detection circuit (19). Further, the third edge detection circuit (17) detects a rising edge of the ultrasonic signal from the ultrasonic signal source (12), and detects the rising edge of the ultrasonic signal from F in FIG. 2 corresponding to the rising edge. A pulse signal as shown is output. The pulse signal 5 obtained by the third edge detection circuit (17) is supplied to the distance calculation circuit (18). The distance calculation circuit (18) is composed of the pulse signal obtained by the third edge detection circuit (17) indicated by Δ, in FIG. 2 and the pulse signal obtained by the first edge detection circuit (15). The time difference t between corresponding pulses in the signal, and the pulse signal obtained by the third edge detection circuit (17) indicated by ΔΤ2 in FIG. ₂ and the pulse signal obtained by the second edge detection circuit (16) It is detecting the time difference t ₂ between the corresponding pulses in the pulse signal. Then, based on each of these time differences, t 2 and the sound speed V, an arrow ^ in FIG. The distance ^ between the ultrasonic speaker (13) and the center of the listener's head (Μ), indicated by. Is calculated.

The sound velocity V may be set in advance in the distance calculation circuit (18) as a constant, or may be changed according to changes in temperature, humidity, air pressure, and the like. The distance ^ is calculated based on the positional relationship between the signal detectors (5L) and (5R) and the center of the head (Μ) and the shape and size of the head (Μ). Correction may be performed. The above distance ^. The signals indicating the time differences t 1, t ₂ are sent to the angle calculation circuit (20).

The aural time difference detecting circuit (19), corresponding in the pulse signal of the pulse signal of the indicating by the delta T ₃ in FIG. 2 the first edge detection circuit (15) and the second edge detection circuit (15) detecting the time difference t ₃ between pulses. Signal indicating the time difference t ₃ This is sent to the angle calculation circuit (20).

In the angle calculating circuit (20), each of the time difference t,, t _2, t _3, said distance ^. Using the sound velocity V and the radius r of the head (M), an arrow in FIG. An angle 0 indicating the direction of the head (M). Calculate the angle 0 above. Is, for example, ^ o -sin- ¹ {V ² (t, + t ₂ ) t 3/4 r ^} ... It can be obtained by the first equation. The angle 0 indicating the relative positional relationship between the reference position and the head (M) of the listener, with the position of the ultrasonic speaker (13) 'as the reference position of the virtual sound source. And distance. From this information, the rotation angle of the head (M) with respect to the desired virtual sound source position and the relative distance from the virtual sound source are calculated.

The angular position information of the listener obtained by the angle calculation circuit (20) is supplied to a control circuit (21).

In the acoustic signal reproducing device of this embodiment, the arithmetic unit (14) is configured to include a transfer characteristic indicating a transfer characteristic from a virtual sound source to at least two ears of the listener in at least one quadrant of the rotation angle position of the listener's head. information, for example, as shown in FIG. 4, the predetermined angle 0 in the first quadrant, and a storage circuit (22) for storing transfer characteristics information for each ~ 0 _{I n.}

Then, based on the current angular position information calculated by the angle calculating circuit (20), the control circuit (21) determines whether the current angular position is in the first quadrant of FIG. The transfer characteristic information corresponding to the current angles 0 _,, to 0 _ln positions is read from the storage circuit (22) as it is, and if the current angle position exists in the second quadrant of FIG. 4, From the storage circuit (22), the transfer characteristic information in which the current angles 0 ₂ ] to 0 _2n correspond to the angles 0 H to 0 _ln positions of the first quadrant is read out. If it exists in the third quadrant of FIG. 4, the transfer characteristic information corresponding to the current angle S ₃ ,..., 0 ₃₁₁ corresponding to the angle _ln position of the first quadrant is read from the storage circuit (22). Furthermore, the memory circuit (22) from the current angle of 0 ₄ when the current angular position are exist in the fourth quadrant of Figure 4 , ~ 0 "corresponding to the angle 0 position in the first quadrant. Then, the transfer characteristic information is supplied to the acoustic signal processing circuit (23) together with a signal indicating the quadrant to which the current angular position belongs.

Here, since the listener's head has a substantially spherical rotationally symmetric shape, the transfer characteristics from the virtual sound source to the listener's both ears can be treated as symmetric in each quadrant.

Note that the control circuit (21) reads two pieces of transfer characteristic information near the head rotation angle position indicated by the angle position information from the storage circuit (22), and performs, for example, linear interpolation processing on the current transfer characteristic information. The transfer characteristic information at the position of the head rotation angle may be calculated. ·

Above the sound signal processing circuit (23), left Chiya tunnel and right Chiya tunnel acoustic signal Ru is outputted from the acoustic signal supply source (22) S _L, is S _R are supplied. Incidentally, the acoustic signal supply source (24) is a predetermined left channel and right Chiya tunnel acoustic signals S _L, apparatus for outputting SR, for example, various recording disk reproducing apparatus, a recording tape player, or And a radio wave receiving device.

The sound signal processing circuit (23) includes, in the left channel and right channel sound signals S i_, SR sent from the sound signal supply source (24), predetermined transfer characteristics from a virtual sound source to both ears of a listener. This is a circuit that performs signal processing to provide the following: 1st to 6th switching switches for switching signal lines (25 switches), (25R), (26L), (26R), (27 switches), (27R switches) ) and first to fourth signal processing section performs a process of providing the transfer characteristic (28a), (28b), (28c), (28d) c of the first to become equipped with such sixth switching sweep rate Tutsi ( The (25L), (25R), (26L), (26R), (27L) and (27R) control the signal from the control circuit (21) indicating the quadrant to which the current angular position belongs. Switching is controlled as a signal. Said first switching Sui Tutsi (25L) and a second switching sweep rate 'Tutsi (2 5R), said left channel acoustic signal transmitted from the audio signal source (24) S _L and the right channel acoustic signal S but intends line input switching for _r, to the when the current angular position belonging to the first quadrant or the third quadrant, the right channel acoustic signal S _R to the first and second signal processing unit ( 28a), (both supplied to 28b), the left channel acoustic signal S _L said third and fourth signal processing section (28c), (is supplied to 28d), also the current angular position second When belonging to the quadrant or the fourth quadrant, the left channel sound signal is supplied to the first and second signal processing units (28a) and (28b), and the right channel sound signal S _R Is supplied to the third and fourth signal processing units (28c) and (28d).

Further, the third switching sweep rate Tutsi (26L) and the fourth switching sweep rate Tutsi (26R) is an acoustic signal E _L of the left and right tea N'ne Le output from the audio signal processing circuit (23), the output of the E _R A switch for adding the output signals of the first and third signal processing units (28a) and (28c) when the current angular position belongs to the first quadrant or the third quadrant. first adder by selecting the output signal of the (29R) as the acoustic signal E _R of the right channel monitor, the second and fourth signal processing section (28b), first adding the output signal of (28d) The output signal of the adder 2 (29L) is selected as the sound signal E of the left channel, and when the current angular position belongs to the second or fourth quadrant, The output signal of the adder (29R) is selected as the sound signal 左 ι ^ of the left channel, and the second Selects the output signal of the adder (29L) as the acoustic signal E _R of the right channel.

In addition, the third switch (26L) and the fourth switch Lee pitch (26R) is an acoustic signal E _L of the left and right tea down channel to be output from the audio signal processing circuit (23), performs Ficoll Le evening switching of ER, the current angular position first quadrant or the in the case belonging to quadrant, to the time the acoustic signal EL to the left and right switch ya tunnel, the E _R outputted as it is, the current angular position belongs to the second quadrant or the fourth quadrant, mouth one passphrase Filter (30

L), and outputs the acoustic signal EL, E _R which removes high-frequency components by (30R). In each of the signal processing units (28a), (28b), (28c), and (28d), the signal processing units (28a), (28b), (28c), and (28d) are spaced apart from the listener based on the transfer characteristic information supplied from the control circuit (21). The left and right channel sound signals S: _,, are used as a virtual sound source with a pair of installed speed devices for the left and right channels.

An impulse response that expresses the transfer characteristic of the listener to each ear when reproducing S R is set.

That is, the first signal processing unit (28a) sets an impulse response {h _RR (t, θ)} representing a transfer characteristic of the sound reproduced from the right channel sound signal SH to the right ear. The second signal processing unit (2 8b) sets the right channel acoustic signal S _R b to express the transfer characteristic for the left ear of the sound reproduced down pulse response _{{h R i_ (t, θ} )} . Said third signal processing section (28c) sets the I Nparusuresupo Nsu the left channel acoustic signal S representing the transfer characteristic for the acoustic of the right ear reproduced _{{h LR (ΐ, θ)} }. The fourth signal processing section (28d) sets the left channel acoustic signal {and h _L (t, Θ)} fin pulse response representing a transfer characteristic for the acoustic of the left ear reproduced, and, to come to the current angular position of the listener's head belongs to the first quadrant, the right channel acoustic signal S _R, the first signal processing unit (28 a) and the second signal processing unit (28b). The first signal processing unit in (28a), subjected the fin pulse response _{{h RR (t, θ)} } a convolutional integration by signal processing in the right channel acoustic signal S _R. In the second signal processing section (28b), the impulse response {h ^

(T, θ) convolving by signal processing} applied to the right channel acoustic signal S _R.

Further, the left channel acoustic signal S is sent to the third signal processing section (28c) and the fourth signal processing section (28d). The third signal processing unit in (28c), said fin pulse response _{{h LR (t, θ)} } the convolution integration by signal processing 'applied to the left channel acoustic signal S _L. The second signal processing unit (28d) performs signal processing on the left channel acoustic signal SL by convolution of the impulse response {h (t, θ)}.

Then, the output signals of the first signal processing section (28a) and the third signal processing section (28c) are supplied to the right channel adder (29R) and added to each other. The output signal of the right channel adder (29R) is passed through the right channel amplifier (31R) as a right channel acoustic signal E _R to the right channel of the headphone device (10). It is sent to the headphone unit (2R) and played. The output signals of the second signal processing unit (28b) and the fourth signal processing unit (28d) are supplied to a left channel adder (29L) and added to each other. The output signal of the left channel adder (29L), the left Chiya tunnel amplifier (31 L) through to the acoustic signal E _L for the left channel Tsu Dohon device to said left channel (10) It is sent to the headphone unit (2L) and played.

Also, when the current angular position of the listener's head belongs to the second quadrant Then, by performing the same processing as in the first quadrant described above by exchanging the left and right channels of the input and output, it is possible to obtain a sense of forward localization. Further, when the current angular position of the listener's head is in the third and fourth quadrants, the same processing as in the first and second quadrants is performed, and the above-mentioned one-pass filter is performed. (30L), the acoustic signal EL to remove the high frequency components by (30R), by outputting the E _R, audio signal reproducing apparatus constructed comprising embodiments as _c above can be obtained rear localization In the above, based on the transfer characteristic information of the first quadrant stored in the storage circuit (22), the rotation angle position corresponding to the listener's head movement calculated by the angle calculation circuit (20) is calculated. The above-described acoustic signal processing circuit (23) performs signal processing to form transfer characteristic information and to respond in real time to changes in transfer characteristics due to listener movement and rotation of the head (M) using the left channel and right channel. Chiya tunnel of the sound signal S _L, by performing the SR, e.g. As shown in Fig. 5, A, B, and C show the relative positional relationship between the virtual sound source and the listener, a pair of speech force devices (SL) installed in front of the listener (P) and separated from each other. As in the case of reproducing an audio signal by means of) and (SR), a good out-of-head localization sensation and a forward localization ゃ rear localization sensation can be obtained without the virtual sound source moving.

Here, FIG. 5 shows a state in which the listener (P) approaches the virtual sound source from a state in which the listener (P) is positioned as shown at A with respect to the pair of speaker devices (S, (SR), that is, the virtual sound source). Is shown in B, and the state in which the listener (P) rotates the head (M) to the right speaker device (SR) is shown in C. In the acoustic signal reproducing device according to the present invention, as described above, In addition, by performing signal processing in real time in response to changes in the transfer characteristics associated with the listener's movement and the rotation of the head (M), a good out-of-head localization without moving the virtual sound source is achieved. And a sense of forward localization is obtained, and a bar corresponding to any of the states A, B, and C in FIG. You can perform normal playback.

As described above, in the acoustic signal reproducing apparatus according to the present invention, the storage unit stores the transfer characteristic information indicating the transfer characteristic from the virtual sound source to the listener's both ears in at least one quadrant of the rotational angle position of the listener's head. Since the amount of the transfer characteristic information stored in the storage means is small and the storage capacity is small, it can be used for the storage means. The acoustic signal processing means stores the transfer characteristic information in the head rotation angle position indicated by the detection output by the detection means for detecting the rotation angle position corresponding to the movement of the listener's head in the storage means. At least one quadrant is formed based on the transmission characteristic information, and the left and right channel acoustic signals are processed separately, and the processed audio signals are supplied to the headphone device. If the sound source moves, the virtual sound source position does not move, and it is possible to perform appropriate binaural reproduction with a very g-like sound image localization feeling.

Next, a second embodiment of the audio signal reproducing apparatus according to the present invention will be described in detail with reference to FIG.

The sound signal reproducing device shown in FIG. 6 is attached to the head (M) of the listener by a headband (41) and is similar to the first embodiment described above. A headphone device (40) supporting a pair of headphone units (42L) and (42R) corresponding to the vicinity is provided.

On the headband (41) of the headphone device (40), two sliders (44L) and (44R) having support arms (43L) and (43R) protrudingly formed are slidably mounted. And a pair of signal detectors (45L) and (5R) that sense the position detection reference signal sent from the reference signal source (51) are attached to the distal ends of the support arms (43L) and (43). Is provided. That is, the pair of signal detections The holders (45L) and (45R) are connected to the support arms (43L) and (43R) formed on the sliders (44L) and (44R) slidably mounted on the headband (41). By providing the headband (41) and a pair of headphone units (42L) and (42R) at the distal end, the support arms (43L) and (43R) are located at positions separated from the headphone body. ).

Also in this embodiment, the reference signal source (51) includes an ultrasonic signal source (52) and an ultrasonic speaker (53) for transmitting an ultrasonic signal from the ultrasonic signal source (52) as a reference signal. It is composed of An ultrasonic microphone is used for each of the pair of signal detectors (45L) and (45R) that sense the reference signal.

The ultrasonic wave transmitted from the ultrasonic force (53), that is, the reference signal for position detection, is an intermittent ultrasonic wave of a predetermined level at predetermined time intervals, as in the first embodiment. Such an ultrasonic wave that can be detected in phase, such as a burst wave transmitted to a user or a so-called level-modulated wave whose level fluctuates at a predetermined period.

The pair of signal detectors (45R) and (45R) provided in the headphone device (40) serve as a reference for position detection using ultrasonic waves transmitted from the ultrasonic speaker (53). Upon sensing the signal, each detection signal having a time delay corresponding to the relative positional relationship between the listener and the ultrasonic speed (53) is output.

Each detection signal obtained by these signal detectors (45L) and (45R) is supplied to an arithmetic unit (54).

The arithmetic unit (54) includes first and second edge detection circuits (55) to which detection signals of the reference signal for position detection are supplied by the signal detectors (45R) and (45R). , (56) and a third edge detection circuit (57) to which the ultrasonic signal from the ultrasonic signal source (52), that is, the reference signal for position detection is supplied. Ethical.

The first and second edge detection circuits (55) and (56) detect each rising edge of each detection signal by each of the signal detectors (45L) and (45R), and correspond to the rising edge. Each pulse signal is output. Each pulse signal obtained by the first and second edge detection circuits (55) and (56) is supplied to a distance calculation circuit (58) and a binaural time difference detection circuit (59). The third edge detection circuit (57) detects a rising edge of the ultrasonic signal from the ultrasonic signal source (52) and outputs a pulse signal corresponding to the rising edge. The pulse signal obtained by the third edge detection circuit (57) is supplied to the distance calculation circuit (58).

The distance calculation circuit (58) calculates a time difference t, between a pulse signal obtained by the third edge detection circuit (57) and a corresponding pulse in the pulse signal obtained by the first edge detection circuit (55). , it detects a time difference t ₂ between the corresponding pulses in the third Etsu di detection pulse signal obtained by the circuit (57) out and the second pulse signal obtained by the edge detection circuit (56). Then, each of these time differences t], based on the t ₂ and the sound velocity V, and calculates the distance ^ 0 and the center of the head (M) of the ultrasonic speaker (53) and the listener.

The above distance ^. The signals indicating the time differences t 1, t ₂ are sent to the angle calculation circuit (60).

The aural time difference detecting circuit (59), the time difference t ₃ between the pulse that corresponds in the pulse signal of the pulse signal and the second edge detection circuit (55) of the first Etsu edge detection circuit (55) To detect. Signal indicating the time difference t ₃ is transmitted to the angle calculation circuit (60).

In the angle calculating circuit (60), each of the time difference t,, t _2, t _3, above Distance. Using the sound velocity V and the radius r of the head (M), similarly to the angle calculation circuit (20) in the first embodiment, the head ( Angle 0 indicating the direction of M). Is calculated. The angle indicating the relative positional relationship between the reference position and the listener's head (M), using the position of the ultrasonic speech force (53) as the reference position of the virtual sound source. And distance ^. From this information, the rotation angle Θ of the head (M) with respect to the desired virtual sound source position and the relative distance from the virtual sound source ^ are calculated.

The listening angle position information obtained by the angle calculation circuit (60) is supplied to an interpolation calculation processing circuit (61).

In the acoustic signal reproducing device of this embodiment, the arithmetic unit (54) is configured to detect the listener from the virtual sound source for each predetermined angle that is coarser than the listener's angular position information calculated by the angle calculation circuit (60). A storage circuit (62) for storing transfer characteristic information indicating transfer characteristics to both ears is provided.

Then, based on the current angular position information calculated by the angle calculating circuit (60), the interpolation calculation processing circuit (61) performs two interpolation operations near the head rotation angle position indicated by the angle position information. The transfer characteristic information is read from the storage circuit (62), and the transfer characteristic information at the current head rotation angle position is calculated by, for example, a linear interpolation process.

In addition to the linear interpolation processing, the interpolation calculation processing circuit (61) stores, for example, three or more pieces of transfer characteristic information near the current head rotation angle position indicated by the angle position information in the storage circuit (62). , And may perform the secondary interpolation processing.

The transfer characteristic information at the current head rotation angle position obtained by the interpolation arithmetic processing circuit (61) is supplied to the acoustic signal processing circuit (63). Above the sound signal processing circuit (63), left channel and right channel acoustic signal Ru is outputted from the acoustic signal supply source (64) S _L, SR are supplied. Incidentally, the acoustic signal supply source (64) is a predetermined left channel and right Chiya tunnel acoustic signals S _L, apparatus for outputting SR, for example, various recording disk reproducing apparatus, a recording tape player, or And a radio wave receiving device.

Said sound signal processing circuit (63), the acoustic signal supply source (64) to the left channel and right channel acoustic signals S Ru sent from, a predetermined leading to both ears of the listener from the virtual sound source S _R A first signal processing unit (65a) for supplying a transfer characteristic information at the current head rotation angle position obtained by the interpolation arithmetic processing circuit (61). ), (65b), (65c), (65d). In each of these signal processing units (65a), (65b), (65c), and (65d), based on the above-mentioned transfer characteristic information, the left channel and the right channel are set apart from the listener. left channel and right channel sound-signal as the virtual sound source to spin one force device of one pair for tunnel, fin pulse response is set to represent the transmission characteristics for each ear該聴Tosha when reproducing the S _R You.

That is, the first signal processing unit (65a) sets the right channel acoustic signal SR representing the transmission characteristic for the acoustic of the right ear reproduced impulse response _{{h RR (t, θ)} }. The second signal processing unit (6 5b) sets the right channel acoustic signal S _R to represent the transfer characteristics for the left ear of the sound reproduced Lee down pulse response _{{h RL (t, θ)} }. The third signal processing unit (65c) is an impulse response unit that expresses a transfer characteristic of the reproduced sound of the left channel acoustic signal to the right ear. Set {h _LR (t, 0)}. The fourth signal processing unit (65d) sets an impulse response {hi ^ (t, 0)} representing a transfer characteristic of the reproduced sound of the left channel acoustic signal to the left ear.

In the audio signal processing circuit (63), the right channel acoustic signal S _R, the first and second signal processing section (65a), are sent to (65b). The first signal processing unit in (65a), the fin pulse response _{{h RR (t, θ)} } convolving by signal processing performed on the right channel acoustic signal S _R. Further, in the second signal processing section (25b), said Lee Nparusure Suponsu {h ^ (t, θ) } convolving by signal processing performed on the right Ji Ya tunnel acoustic signal S _R. '

Further, the left channel acoustic signal SL is sent to the third and fourth signal processing units (65c) and (65d). The third signal processing unit in (65c), said fin pulse response {h ^ (t, θ) } The signal processing by convolutional integration of applying to the left channel acoustic signal S _L. Further, the second signal processing unit (65d) performs signal processing by convolution of the impulse response {h (t, Θ)} on the left channel acoustic signal Sl_. The output signals of the signal processing units (65a) and (65c) of No. 3 are supplied to the right channel adder (66R) and added to each other. The output signal of the right-channel adder (66R) is passed through a right-channel amplifier (68R) to a right-channel audio signal E _R as a right-channel audio signal of the headphone device (40). It is sent to Doununit (42R) for playback. The output signals of the second and fourth signal processing units (64b) and (64d) are supplied to a left channel adder (66L) and added to each other. The output signal of the left-channel adder (66L) passes through the left-channel amplifier (68L) as the left-channel acoustic signal Ει_ to the left of the headphone device (40). It is sent to the channel headphone unit (42L) and played.

In the sound signal reproducing apparatus of the embodiment configured as described above, based on the current angle position information calculated by the angle calculation circuit (60), the vicinity of the head rotation angle position indicated by the angle position information The transfer characteristic information at the current head rotation angle position is read out from the storage circuit (62) by, for example, a linear interpolation process, and the transfer characteristic information is calculated by the interpolation calculation circuit (61). Based on the information, the acoustic signal processing circuit (63) performs signal processing in real time to respond to changes in transfer characteristics due to the movement of the listener and the rotation of the head (M). As in the case of reproducing an acoustic signal by a pair of speaker devices installed in front of and separated from each other, a virtual sound source does not move as in the case of reproducing a sound signal. That.

As described above, in the acoustic signal reproduction device according to the present invention, the detection output by the detection unit that detects the listener's head rotation angle position with a higher resolution than the resolution of the transfer characteristic information stored in the storage unit is used. At least two pieces of transfer characteristic information in the vicinity of the head rotation angle position shown are read out from the storage means, and the transfer characteristic information at the head rotation angle position shown by the detection output is interpolated by the interpolation calculation means. However, the amount of transfer characteristic information stored in the storage means can be reduced. The sound signal processing means processes the left channel and right channel sound signals based on the transfer characteristic information obtained by the interpolation operation means, and supplies the processed sound signals to the headphone device. Therefore, even if the listener moves, it is possible to perform proper binaural reproduction with an extremely natural sound image localization without moving the virtual sound source position.

Claims

The scope of the claims

1. Detecting means for detecting a rotation angle position corresponding to a movement of a listener's head with respect to a virtual sound source;

(5) storage means for storing transfer characteristic information indicating a transfer characteristic from the virtual sound source to the listener's both ears in at least one quadrant of the rotation angle position of the head;

Based on the transfer characteristic information of at least one quadrant stored in the storage means, transfer characteristic information at the head rotation angle 10 position indicated by the detection output by the detection means is formed, and the left channel is formed. Signal processing means for processing the input audio signal of the right channel and the input audio signal of the right channel, respectively.

An audio signal reproducing apparatus for reproducing an audio signal through the audio signal processing means by a headphone device.

i s 2. The detection means is:

A pair of signal detection elements for sensing a reference signal transmitted from a reference signal source; and- a phase difference between the output signal detected by the pair of signal detection elements and the reference signal between the reference signal source and the listener's head. A distance calculating means for calculating the distance,

20 a time difference detecting means for detecting a time difference between detection output signals by the pair of signal detection elements,

2. The sound signal reproduction device according to claim 1, wherein the rotation angle position of the listener's head is calculated using the distance information obtained by the distance calculation means and the time difference information obtained by the time difference detection means. apparatus.

2 5 3. The sound signal processing means A first signal processing unit that performs convolution integration of an impulse response corresponding to a transfer characteristic of the input audio signal to the right ear of the right channel reproduction audio signal to the right ear, to the input audio signal of the right channel;

A second signal processing unit that performs convolution integration of an impulse response corresponding to a transfer characteristic of the right channel reproduced sound signal to the left ear on the input sound signal of the right channel;

A third signal processing unit for performing convolution integration of an impulse response corresponding to a transfer characteristic of the input audio signal to the right ear of the left channel reproduced audio signal to the left channel input audio signal;

A fourth signal processing unit that performs convolution integration of an impulse response corresponding to a transfer characteristic of the left channel reproduced sound signal to the left ear to an input sound signal of the left channel;

First adding means for adding the output of the first signal processing unit and the output of the third signal processing unit;

Second adding means for adding the output of the second signal processing unit and the output of the fourth signal processing unit,

The output of the first addition means is supplied to the headphone unit of the right channel of the headphone device, and the output of the second addition means is supplied to the headphone unit of the left channel of the headphone device. The audio signal reproducing device according to claim 1, wherein the audio signal is supplied to the audio signal reproducing device.

4. The storage means is characterized in that transfer characteristic information indicating a transfer characteristic from the virtual sound source to the listener's both ears in the first quadrant of the rotational angle position of the head is stored in advance. The audio signal reproduction device according to claim 1, wherein

5. Corresponds to the head rotation angle position indicated by the detection output by the above detection means The control unit reads the transfer characteristic information of the first quadrant from the storage unit and supplies the transfer signal information to the acoustic signal processing unit together with a control signal indicating the quadrant to which the head rotation angle position indicated by the detection output of the detection unit belongs. The acoustic signal reproducing device according to claim 4, wherein means is provided.

6. The sound signal processing means includes:

A first signal processing unit that performs convolution integration processing of an impulse response corresponding to a transfer characteristic of the input audio signal to the right ear of the right channel reproduced audio signal to the right ear, to the input audio signal of the right channel;

Corresponds to the transfer characteristic of the right channel reproduced sound signal to the left ear

A second signal processing unit for performing convolution integration of the I 0 impulse response on the input audio signal of the right channel;

A third signal processing unit that performs convolution integration of an impulse response corresponding to a transfer characteristic of the input audio signal to the right ear of the left channel reproduction audio signal to the left channel input audio signal;

15 A fourth signal processing unit that performs convolution integration of the impulse response corresponding to the transfer characteristic of the left-channel reproduced sound signal to the left ear on the input sound signal of the left channel;

20 0 second addition means for adding the output of the second signal processing unit and the output of the fourth signal processing unit,

The output of the first adding means is supplied to the headphone unit of the right channel of the headphone device, and the output of the second adding means is supplied to the headphone unit of the left channel of the headphone device. To supply to

The acoustic signal reproducing device according to claim 5, wherein the acoustic signal reproducing device is 25 mm.

7. The sound signal processing means is:

When the control signal indicates the first or third quadrant, the input audio signal of the right channel is supplied to the first and second signal processing units, and the control signal controls the second or fourth quadrant. The first selecting means for supplying the input signal 5 of the right channel to the third and fourth signal processing units, and when the control signal indicates the first or third quadrant, The input audio signal of the left channel is supplied to the third and fourth signal processing units, and when the control signal indicates the second or fourth quadrant, the input audio signal of the right channel is output. A second selecting means for supplying to the first and second signal processing sections ^: selecting the output of the first adding means when the control signal indicates the first or third quadrant; When the control signal indicates the second or fourth quadrant, a third selecting means for selecting the output of the second adding means. Steps and

i s. When the control signal indicates the first or third quadrant, select the output of the second addition means. When the control signal indicates the second or fourth quadrant, select the first output. Fourth selecting means for selecting the output of the adding means,

When the control signal indicates the first or third quadrant, the output of the third selection means is supplied to the headphone unit 0 of the right channel of the headphone device, and the control signal is supplied to the second headphone unit. Or, when indicating the fourth quadrant, fifth selection means for supplying the output of the third selection means to the headphone unit of the right channel via a single-pass filter;

When the control signal indicates the first or third quadrant, the output of the fourth selection means is supplied to the headphone unit 5 of the left channel of the headphone device, and the control signal is the second or third. When indicating the fourth quadrant, 7. The sound signal reproducing apparatus according to claim 6, further comprising: a sixth selecting means for supplying an output of said selecting means to a headphone unit of said left channel via a low-pass filter.

8. Read the transfer characteristic information of at least two first quadrants corresponding to the vicinity of the head rotation angle position indicated by the detection output by the detection means from the storage means, and read the actual characteristic indicated by the detection output by the detection means. 5. The sound signal reproducing apparatus according to claim 4, further comprising interpolation processing means for obtaining transfer characteristic information corresponding to the head rotation angle position by interpolation processing.

9. The interpolation processing means includes the transfer characteristic information obtained by the interpolation processing together with the control signal indicating the quadrant where the actual head rotation angle position indicated by the detection output by the detection means is H, and the acoustic signal processing means. 9. The audio signal reproducing device according to claim 8, wherein the audio signal is supplied to the audio signal reproducing device.

10. Storage means for storing transfer characteristic information indicating a transfer characteristic from the virtual sound source to the listener's both ears at each predetermined rotation angle corresponding to the rotation of the listener's head;

Detecting means for detecting a rotation angle position corresponding to the movement of the listener's head with respect to the sound source;

At least two pieces of transmission characteristic information near the head rotation angle position indicated by the detection output by the detection means are read out from the storage means, and the transmission characteristic at the head rotation angle position indicated by the detection output by the detection means is read out. Interpolating means for interpolating information,

Sound signal processing means for processing the input sound signal of the left channel and the input sound signal of the right channel, respectively, based on the transfer characteristic information obtained by the interpolation calculating means;

The sound signal passed through the sound signal processing means is reproduced by the headphone device. A sound signal reproducing device that produces.

1 1. The above detection means

A pair of signal detection elements for sensing a reference signal transmitted from the reference signal source;

Distance calculating means for calculating a distance between the reference signal source and the listener's head from a phase difference between a detection output signal from the pair of signal detection elements and the reference signal;

A time difference detecting means for detecting a time difference between the detection output signals of the pair of signal detection elements.

10. The rotation angle position of the listener's head is calculated using distance information obtained by the distance calculation means and time difference information obtained by the time difference detection method. Audio signal reproducing device.

1 2. The acoustic signal processing means

A first signal processing unit for performing convolution integration of an impulse response corresponding to a transfer characteristic of the input audio signal to the right ear of the right channel reproduction audio signal to the right ear, to the input audio signal of the right channel;

A second signal processing unit for performing convolution integration of an impulse response corresponding to a transfer characteristic of the right channel reproduced sound signal to the left ear to the input sound signal of the right channel;

A third signal processing unit that performs convolution integration of an impulse response corresponding to transfer characteristics of the input audio signal to the right ear of the left channel reproduction audio signal to the right ear, to the input audio signal of the left channel;

A fourth signal processing unit for performing convolution integration of an impulse response corresponding to a transfer characteristic of the left channel reproduced sound signal to the left ear on the input sound signal of the left channel; First adding means for adding the output of the first signal processing unit and the output of the third signal processing unit;

The output of the first addition means is supplied to the headphone unit of the right channel of the headphone device, and the output of the second addition means is supplied to the headphone unit of the left channel of the headphone device. 10. The audio signal reproducing device according to claim 10, wherein the audio signal is supplied.

1 3. The interpolation calculation means is indicated by a detection output by the detection means.

10 Read out the two transfer characteristic information near the head rotation angle position from the storage means, and perform linear interpolation calculation of the transfer characteristic information at the head rotation angle position indicated by the detection output by the detection means. The acoustic signal reproducing device according to claim 10, characterized in that:

1 4. The interpolation calculation means is indicated by the detection output by the detection means.

5) Reading out three or more transfer characteristic information in the vicinity of the head rotation angle position from the storage means, and performing a secondary interpolation operation on the transfer characteristic information at the head rotation angle position indicated by the output detected by the detection means. Claims characterized by the following:

10. The acoustic signal reproduction device according to 10.

2 0

twenty five