WO2005069680A1

WO2005069680A1 - Sound receiving arrangement comprising sound receiving means and sound receiving method

Info

Publication number: WO2005069680A1
Application number: PCT/IB2005/050037
Authority: WO
Inventors: Martin Koch
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2004-01-07
Filing date: 2005-01-05
Publication date: 2005-07-28

Abstract

In a sound receiving arrangement (1), two microphones (4L, 4R) are provided for the reception of sound, which microphones are arranged on the sound receiving arrangement (1) in such a manner that, when the sound receiving arrangement (1) is worn on a user's head, one microphone (4L) can be positioned on the left side of the user's head and one microphone (4R) on the right side of the user's head.

Description

Sound receiving arrangement comprising sound receiving means and sound receiving method

The invention relates to a sound receiving arrangement, which is designed to be worn on a user's head, with sound receiving means which are designed for receiving sound. The invention further relates to a sound receiving method for receiving sound.

What is called video technology has made considerable progress with regard to the image quality in recent years, but the quality of audio recording has not kept pace with it. Video cameras in the consumer range and in the semi-professional range mostly have a stereo microphone placed near the objective of the camera, the principal sensitivity of the microphone extending in the direction of the optical axis of the objective. There are also video cameras, which have a shoe for putting a directional microphone on. The sound recording quality of these video cameras, due to the positioning and directional effect of the microphone used, can be satisfactory only if this sound reaches a microphone more or less parallel to the direction of the optical axis of the objective of the video camera. Ambient noise and commentary spoken by the cameraman, however, always seem to the watcher to come from the background, i.e. from positions beside or behind the image displayed. There is thus a need for improvement in the sound quality of film and video recordings, especially in the consumer range and in the semi-professional range. It would be particularly desirable to be able to improve the spatial properties and naturalness of sound recordings without needing any expensive sound transmission equipment and sound recording equipment, such an improved sound recording and sound transmission even beyond the film and video technology being desirable, say, also in the radio field, to improve the sound quality of interviews and reports considerably.

It is an object of the invention to provide a sound receiving arrangement of the type mentioned in the first paragraph and a sound receiving method of the type mentioned in the second paragraph, in which the disadvantages described above are avoided. To provide a solution for the above-mentioned object, the features as invented have been provided on a sound receiving arrangement as invented, such that a sound receiving arrangement as invented can be characterized in the manner mentioned below, namely: Sound receiving arrangement, which is designed to be worn on a user's head, with sound receiving means which are designed for receiving sound, wherein the sound receiving means comprise two microphones arranged on the sound receiving arrangement in such a manner that it is possible for a user, while wearing the sound receiving arrangement, to position one microphone on the left side of the head and one microphone on the right side of the head. To provide a solution for the above-mentioned object, features as invented are provided in a sound receiving method as invented, such that a sound receiving method as invented can be characterized in the manner mentioned below, namely: Sound receiving method for receiving sound with the help of a sound receiving means provided in a sound receiving arrangement, the sound receiving means comprising two microphones, wherein sound on the left side of the head of a user wearing the sound receiving arrangement is received by the one microphone positioned there and on the right side of the head by the other microphone positioned there. By providing the features as invented, a good spatial perception and high natural effect in the reproduction of sound recordings can be achieved, which correspond to those from dummy head recordings, because a listener is almost taken to the recording room of the recording which the user is currently listening to, due to the positioning of the two microphones of the invented sound receiving arrangement, on the left and right halves of the user's head. The listener experiences the differences in the intensity, propagation time and tone colors in the sound signals of such a recording by this microphone technology, similarly to the ones the user of the sound receiving arrangement experiences when he hears the sound. The sound receiving arrangement as invented is especially eminently suitable for video recording, because the simultaneous image and sound recording helps eliminate the disadvantage attributed to the dummy head recording process. This disadvantage is that with pure sound recordings by means of a commercially available dummy head this binaural recording technique does correctly imitate the acoustic proportions for one watcher as such, but that many listeners still complain about the impression that their head is rigidly connected (acoustically) to the dummy head. The psychoanalytical explanation for this rigid connection effect is that the human auditory system gets its directionality from the modifying of the sound signals by the head itself and the outer ears and the intensity and sound color differences going with them, man, however, subconsciously rechecks the sound sources localized by the hearing with his eyes by casting an eye on the sound source or having the head move to and fro to "take his bearings". If the listener can also visually check the position of a sound source determined by the hearing in this manner, it gives him the subjective impression of a particularly natural sound reception from the direction subjectively correct for him. It can be mentioned that headsets are known, which have a microphone fitted on an arm in addition to one or two earphone capsules, which microphone can be positioned near the user's mouth to record his voice, when the sound receiving arrangement is worn. Such sound receiving arrangements are used, for example, by telephone operators and for what are called intercom units, so that persons can have speech communication with each other and still have both hands free. According to the measures mentioned in claim 2 and claim 12 respectively, the advantage derived is that of improved naturalness of the sound reception, because the head of the user of the sound receiving arrangement provides differences in the intensity, propagation time and sound colors of the received sound between left and right sides of the head, which differences a listener experiences from an audio recording made with the help of the sound receiving arrangement in the same manner as the user and is thus almost transferred to the sound reception situation of the user. According to the measures as mentioned in claim 3 and claim 13 respectively, the advantage derived is that the head of the user contributes towards carrying out dummy head recordings, without having to accept the inadequacies of the commercially available dummy heads, such as a distorting frequency response. According to the measures mentioned in claim 4 and claim 5 respectively, the advantage derived is that the invented sound receiving arrangement offers the user great wearing comfort. According to the measures mentioned in claim 6 and claim 14 respectively, the advantage derived is that bad room acoustics, which are noticeable for example in the form of pronounced sound reflections, can be compensated. According to the measures as mentioned in claim 7 and claim 15 respectively, the advantage derived is that comments by the user of the sound receiving arrangement are received in good quality and as foreground sound. A listener thus experiences these comments not from the background but as a foreground sound, on which he can concentrate. According to the measures in claim 8 and claim 16 respectively, the advantage derived is that the separate transmission of the electrical audio signals from the microphones allows mixing and/or processing and/ or modifying the electrical audio signals in a subsequent audio signal-processing device. According to the measures in claim 9 and claim 17 respectively, the advantage derived is that of high wearing comfort, because the user of the sound receiving arrangement is not hampered or restricted by cables. According to the measures of claim 10 the advantage derived is that no body sound is transmitted to the microphone. These and other aspects of the invention are apparent from and will be elucidated, by way of non-limitative example, with reference to the embodiment(s) described hereinafter.

In the drawings : Fig. 1 shows a perspective view of a sound receiving arrangement as invented.

Fig. 1 shows a sound receiving arrangement as invented, which in the present case realizes what is called a headset 1. The headset 1 comprises a yoke 2 made from an elastic material, which can be adjusted such that it will fit the shape of the headset user's head. A padded earphone capsule 3 is swivel-mounted at one end of the yoke 2. A padded element 5 is provided at the other end of the yoke 2 for resting on the user's left temple. The user places the headset in such a manner that the earphone capsule 3 rests on the user's right ear, on the other hand the padded element 5 being designed such that it leaves the user's left ear free so that he can listen to the ambient sounds without disturbance. Alternatively to the padded element 5, a second earphone capsule could also be provided. The earphone capsule 3 serves to feed acoustic information to the headset user, for example, with intercepted signals of a sound recording. The invented headset 1 shows sound recording means, comprising two microphones 4L, 4R, which are placed on the headset in such a way that they are positioned as symmetrically as possible on the left or the right side of the user's head when he wears the headset 1. More precisely, the microphone 4R is mounted on the outside of the earphone capsule 3 and can be adjusted with the capsule together with the yoke 2 of the headset 1. The microphone 4L is fixed on the outside of the padded element 5 (and cannot therefore be seen in the perspective illustration in Fig. 1, but is shown by an arrow). The two microphones 4L, 4R are vibration-damped so that as little body noise as possible is transmitted to the microphone. The user wears the headset such that the two microphones 4L, 4R are positioned near his left or right ear. This makes it possible to ensure that the sound waves received by the microphones 4L, 4R correspond to that sound which is perceived by the user's ears. Thus the two microphones 4L, 4R capture exactly the same sound image as the user also perceives it. Similarly, the differences in intensity and sound colors caused by the sound shading and bending of the sound waves by the user's head correspond to those perceived by the user's ears. High- value stereophonic sound reception and therefore a high-quality sound recording are achieved thereby, so that the reproduction provides high naturalness and good spatial impression. The result of the invented technique of sound reception on microphones which are placed as close to the left ear and right ear of a user of the headset 1 as possible is comparable to that of the dummy head recordings. A dummy head is an imitation of a human head made of plastic, where even the ears and auditory canals are imitated or at least indicated and sound recording microphones are inserted in the imitated auditory canals. An important difference of this present invention with respect to the conventional dummy head recordings is, however, that a high- value sound recording is obtained from the invented headset lwith only low expenditure and the user of the headset 1 follows the sound reception process all the time, because he receives the same sound as the microphone arranged in his ears. On the contrary, a dummy head is placed at a fixed given place, selected by a person responsible for the sound recording and remains at this place for the whole recording in the orientation selected by the person, so that there will be discrepancies between the localization of the sound sources in the picture and their localization through the sound reproduction in video recordings, which are unpleasant to the listener. The microphones 4L, 4R can be designed as microphones with spherical directional characteristics. As an alternative to this, the two microphones 4L, 4R can also have a kidney-shaped directional characteristic. In the latter case it is advantageous for the microphones to be placed on the headset and adjustable, so as to adjust their main efficiency best to the sound field where the user is located, and thereby to balance poor room acoustics. It should be mentioned that extremely small, but still high- value microphones have meanwhile become available, so they can be introduced in the auditory canals of the user. The invention thus extends the known dummy head recording technique to a "real head" recording technique, where the problematic characteristics of a dummy head, such as its distorting frequency response, need not be considered. The headset 1 as invented shows one more microphone 7 for receiving the user's speech. This microphone 7 is placed at a free end of a microphone arm 6, the other end of which is placed on the yoke of the headset in such a manner that the microphone arm can be swiveled. This lets the microphone 7 be placed near the headset user's mouth to record his voice. This makes it possible to make a well-understandable recording of the user's commentary for a video recording instead of feeding a ghostly voice from the background to the listener as happens in the systems already known. The electrical output signals of the microphones 4L, 4R, 7 are transmitted separately to audio signal processing means through the cores of a cable 9, which are depicted in the example of embodiment as the audio input stage of a video camera 10. The received audio signals can be processed at this audio input stage as desired, i.e. amplified, attenuated, filtered and mixed. Alternatively, the audio signals can also be made available in an electronic circuit in the headset. In the embodiments of the headset 1 as shown, a comparatively smaller image reception stage 8 is further mounted on the yoke 2, which has an optical lens system and an electronic circuit for making the image captured by means of the lens system available in an electronic format. This design also makes it possible to capture images and to transmit them to a video camera 10 through the cable 9 as a video signal, i.e. electronically. The lens system of the video camera 10 is designed to be removable for this purpose, as shown in the Fig. 1. The lens system can be mounted either on the camera 10 or on the headset, so the video camera user can carry it in a waist bag, for example and has both hands free during video recording. The video camera mounted on the headset 1 captures images, which correspond to the orientation of the head, where the microphones (4R, 4L) mounted on the headset (1) receive acoustic signals, as the user in the respective position or orientation of his head does. This ensures thus a reproduction of the audio signal corresponding to the visual impressions and, above all, authentic in respect of directions, while a video film is being recorded by means of the video camera. It should be mentioned that the electronic signals can also be created by making use of transmission devices designed for wireless transmission of signals or data, for example radio frequency transmission means (for example, Bluetooth devices) or infrared transmission devices etc. It should be mentioned that the earphone capsule 3 shown in Fig. 1 need not be provided or that it is possible to provide two such earphone capsules 3, one for each ear. The microphone 7 is also not compulsory. It may also be mentioned that the sound recording device 1 can also be designed for being worn on the user's head in such a manner that the sound receiving means can be worn by the user's ears (for example, the outer or inner ear lobes) and, optionally, a connecting yoke can be provided for both microphones.

Claims

CLAIMS:

1. A sound receiving arrangement (1), which is designed to be worn on a user's head, with sound receiving means which are designed for receiving sound, wherein the sound receiving means comprise two microphones (4L, 4R) arranged on the sound receiving arrangement (1) in such a manner that it is possible for a user, while wearing the sound receiving arrangement (1), to position one microphone (4L) on the left side of the head and one microphone (4R) on the right side of the head.

2. A sound receiving arrangement (1) as claimed in claim 1, wherein the one microphone (4L) is arranged on the sound receiving arrangement (1) in such a manner that it can be positioned in areas at or near the user's left ear and where the other microphone (4R) is arranged on the sound receiving arrangement (1) in such a manner that it can be positioned in areas at or near the user's right ear.

3. A sound receiving arrangement (1) as claimed in claim 2, wherein the two microphones (4L, 4R) are arranged on the sound receiving arrangement (1) in such a manner that they can be inserted in the auditory canals of the user's ears when the user wears the sound receiving arrangement (1).

4. A sound receiving arrangement (1) as claimed in claim 1, wherein the two microphones (4L, 4R) are mounted, preferably adjustably, on a yoke (2) of the sound receiving arrangement (1).

5. A sound receiving arrangement (1) as claimed in claim 1, wherein the sound receiving arrangement (1) comprises at least one earphone capsule (3) on which one of the two microphones (4L, 4R) is mounted.

6. A sound receiving arrangement (1) as claimed in claim 1, wherein the two microphones (4L, 4R) have a directional sound reception characteristic and are flexibly mounted on the sound receiving arrangement (1) in such a manner that they can be adjusted with respect to their main sound receiving arrangement.

7. A sound receiving arrangement (1) as claimed in claim 1, wherein the sound receiving means have another microphone (7), which is designed and arranged for receiving the user's voice.

8. A sound receiving arrangement (1) as claimed in one of the claims 1 and 7, wherein electrical audio signals from the microphones (4L, 4R; 7) can be transmitted separately to the audio signal-processing unit (10).

9. A sound receiving arrangement (1) as claimed in claim 8, wherein the electrical audio signals from the microphones (4L, 4R, 7) can be transmitted wirelessly to the audio signal-processing unit (10).

10. A sound receiving arrangement (1) as claimed in claim 1, wherein the two microphones (4L, 4R) are mounted with vibration dampers on the sound receiving arrangement.

11. A sound receiving method for receiving sound with the help of sound receiving means provided in a sound receiving arrangement (1), the sound receiving means comprising two microphones (4L, 4R), wherein sound on the left side of the head of a user wearing the sound receiving arrangement is received by the one microphone (4L) positioned there and on the right side of the head by the other microphone (4R) positioned there.

12. A sound receiving method as claimed in claim 11, wherein one microphone (4L) arranged on the sound receiving arrangement (1) is positioned in areas at or near the left ear and the other microphone (4R) arranged on the sound receiving arrangement (1) is positioned in areas at or near the right ear of the user when the sound receiving arrangement (1) is worn for receiving sound.

13. A sound receiving method as claimed in claim 12, wherein the two microphones (4L, 4R) are inserted into the auditory canals of the user's ears while the sound- receiving device is worn by the user for receiving sound.

14. A sound receiving method as claimed in claim 11 , wherein the two microphones (4L, 4R) have a directed sound reception characteristic and are adjusted for receiving sound with respect to their main sound receiving arrangements.

15. A sound receiving method as claimed in claim 11, wherein sound of the user's voice is received by another microphone (7) arranged on the sound receiving arrangement (I)-

16. A sound receiving method as claimed in claims 11 and 14, wherein electrical audio signals from the microphones (4L, 4R; 14) are transmitted separately to audio signal processing means (10).

17. A sound receiving method as claimed in claim 16, wherein the electrical audio signals from the microphones (4L, 4R, 7) are transmitted wirelessly to audio signal processing means (10).