Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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S334 li B~CI~GI~OI~NV OF THE INVENIION
The present invention relates to an improved audio headphone, and
¦ more particularly to a headphone arrangement inc~uding amplification means in the
signal path to one speaker in each of the heudphones, and an irnproved method ofusing multi-speRker headphones.
Quadraphonic or four-channel headphones are well-known. Réferences
¦I which show particular embodiments of such devices are U. S. Patent No. 3,984,885,
issued to Yoshimura, et al on October 12,1976 and U. S. Patent No. 3,927,262, issued
to Goeckel on December 16, 1975. Generally speaking, such devices comprise an
I earpiece or heRdphone for each ear in which is contained at least two separate
¦ speakers. The purpose of such headphones is to reproduce quadraphonically recorded
~ information such as music with the overall purpose being of more realistically
-I ¦ recording and reproducing sound. The above-referenced patents and the references
- ¦ cited therein generally relate to improvements in such headphones which are
, 15 11 intended to avoid the problem generally ençoantered in headphones in which the
~i~ source of the sound appears to the listener to be in the center of his head.
Studio musicians are, of course~ quite skilled in the art of guadraphonic
sound recording and reproduction. Such musicians often use such equipment for
listening to a pre-recorded track while sim~taneously playing their own instrument
¦ as u practice aid. Of course, if a musician is using headphones which tend to block
out the sound of his own instrument, he must typically feed the output of his
instrument to an electronic mixing network which then el~ctronically combines the
recorded soundtrack with the output of his instrument and then couples the mixedl output with sufficient power to his headphones so that he is able to compare the
1 prerecorded signal with that which he is generating. Similar equipment is used in
the process of overdubbing or re-recording in which a musiciarl performs a particular
musical composition a number of times with the same or different instruments with
each performance recorded over that previously performed. It is, of course,
necessllry in such practice that the musician be able to listen simult~neously to the
prerecorded track and to his presently performed music.
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-533~l It can be seen thQt relatively expensive ec~uipment has been required
for such practice track-mnking, re-recording, etc., since typically studio
quadrnphonic or stereophonic mixing and amplification equipment has been used to¦ provide the combined signals to the rnusician's headphones. It can also be seen that
¦ in the process of electronically rnixing prerecorded and presently produced sounds,
the user of the headphones receives both signals~from precisely the same source,, thùs, reducing his ability to distinguish between the two.
Such typical studio practices would also be quite useful for home or
classroom practice and teaching. But since the studio equipment is quite expensive,
it is not practical for most musicians, especially students, to use the studio methods.
The usual practice methods have involved simply playing a recorded selection
through standard amplifiers and loud speakers while the musician plays his
instrument through separate amplifiers and speakers. In a classro4m situation, an
instructor may be providing the original audio signal while the students p]ay fllong
trying to compare their . performance to the instructor's. In either of these
-~ ¦ situations, the musicians have the problem7 magnified by modern amplifiers, that
their practice is a nuisance to others. In addition, if more than one rnusician tries to
practice at the same time, each has trouble distinquishing his individual performance
from the others. An instructor would likewise haYe trouble isolating a particular
student's performance from the others.
Thus, it is seen that there is a need for an inexpensive practice aid
which allows musicians to listen to two distinct audio signals at the same time for
comparison purposes. In addition, the practice aid should isolate the audio signals
from the surroundings and isolate the user of the aid from audio signals, other than
the two desired signals.
SUMMARY OF Tl-lE INVENTION
-¦ Accordingly, an object of the invention is to provide an irnproved but
inexpensive headphone arrangement which allows a listener to distinguish betweerseparate signal sources.
Another object of the present invention is to provide a headphone
arrangernent with which a musician may simultaneously listen to a pre-recorded
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-533~1 ¦ track and a presently produced originfll perforMance for cornparison purposes.
Yet another object of the present invention is to provide a headphone
I arrangement with which a musician may simultaneously amplify and monitor his
¦ instrument's output while listening to another audio signal. I
I These and othar objects of the present invention are achieved by
providing a multi-channel headphone having means for coupling a first audio signal
¦ to first speaker means in each headphone and rneans for connecting the output of an
j instrument through an amplifier to second speaker means in each headphone.
;~ BRIEF DESCRIPTION OF THE DRAWINGS
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The present inven tion may be oetter understood by reading the
following brief description of the preferred embodiments with reference to the
accompanying drawings wherein: -
¦ Figure I is a block diagram of the amplifier headphone arrangement of the present invention and
¦ Figure 2 is a schematic illustration of the amplifier and switching
; ~ network of Figure 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to Figure 1, there is illustrated an improved four-
channel headphone arrangement according to the present invention. This arrange-
I ment comprises headphones 2 and 4 und a network 6 containing switching
¦ arrangements and at least one amplifier. Headphone 2 comprises first and second
¦ - speakers 8, 10, mounted in a housing 12 having a cushion 14 ~round its open edge for
sealing to the head of a user, Headphone 4 is essentially identical, having first and
second speakers 16 and 18 mounted in a housing 20 having a cusllion 22 around its
open edge. A pair of leads 24 are connected to speakers lb and 18 and are adapted at
their ends 26 for connection to a source for audio signals, such as a stereo amplifier.
¦ It is apparent that each of the leads 24 actually comprises two wires, that is a signal
line and a ground return line, while only one is illustrated for simplicity.
The remaining two speakers 8 and 16 are connected by leads 28 to the
output of a switchin~ and amplifier box described in more detail with reference to
~ Figure 2. Inputs to box 6 are connected by leads 30 to a pair of input terminals 32
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~-5334 ¦¦ whic}l are also ad~pted for connection to a source of audio signals such as a stereo
¦¦ amplifer, but preferably such as a musical instrume!lt. It is apparent in this case
also that leads 28 and 30 each comprise a pair of wires instead of a single wireillustrateà for simplicity.
! While amplifier and switch box 6 is shown as a separate component, it
¦ is preferably built in to either housing 12 or 20. This avoids the need for a separate
housin~, thus reducing the overall size, weight, and cost of ~he whole unit. In
~; ¦ addition, it is quite annoying to have a small extra housing hanging in the rniddle of
the connecting wires. The amplifier unit is preferably powered by a nine volt
transistor radio battery. It is preferable to mount this battery in the housing 12 or
20 which does not contain the amplifier and switch. In a prototype unit, the battery
was placed within a cushion 13 attached to a headband 21 which physically connects
the headphones 2 and 4 together and holds them on the user's head.
I It is also apparent that while wires 24 and 30 have been illustrated as
ll the means for coupling two sets of signals to headphones 2 and 4, other means would
il also be suitable. It has now become practical to use low power FM transmitters and
~¦ receivers to replace microphone or instrument cables. While these are now used
! principally for stage performances9 they wo~d ~lso be ~daptable for use with the
~ headphones of the present invention.
I While input 32 is described as adapted for connection to the electrical
output of, for ex~mple, an electric guitar, a microphone output could also be used.
Thus, musicians with non-electrical instruments may use a microphone to monitor
their instruments and the amplifier in box 6 will provide sufficient power to drive
¦ speakers 8 and 16.
¦ Pigure 2 illustrates one form of the switching and amplifier network 6
of Figure 1. Input and output leads 30 and 28 are the same as those illustrated in
Figure 1. A first double-pole/double-throw switch 34 is connected to input leads 30
and a second similar switch 36 is connected to output leads 28. The switches 34 and
36 are linked together as shown so that they are all switched simultaneously. In the
3D ~ position il streted In Figure 2, the switches 34 end 36 m=ke e direct connection
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-5334 ¦ between input 30 and output 28 by means of internal leads 38 within the switching
¦ box 6. In the alternate position of switches 34 and 3Ç, one of the two input leuds 31)
¦ is connected to the input of an amplifier 40 and the output of the amplifier is
coupled to both of the output leads 28. With this arrangement, the signal appearing
1 on only one of the leads 30 is amplified and coupled simultaneously to both of the
outputs 28. While it is apparent that a second arnplifier 40 could be provided for the
¦¦ second input 30, this is unnecessary in most practice, overdubbing7 etc., applications.
¦ In general, the musician using the device is playing one instrument which has a single
I output and thus his performance is basically monauraL The arrangement of Figure 2
¦ amplifies this monaural output and couples it to each of the speakers 8 and 16 for
I comparison to signals received in speakers 10 and 18. ~mplifier 40 is powered oy a
¦I battery 42.
i In the prototype, the switch 34, 36 also had a center position at which
no contacts were closed. This arrangement provided an "off" position for speakers 8
lS ~ and 16. Although not illustrated, it is apparent~that various filters may be used as
tone controls or compensation networks. ~or example, an input matching network
might be desirable if a microphone is connected to inputs 32. Such filters are not
used in the preferred form since the invention is intended as a monitor or practice
aid and the headphone signals ure not being permanently recorded. U. S. Patent
4,087,631 issued to Yarnada, et al on May 2, 1978, teaches various filter
¦ arrangements for improving headphone sound which could be used if desired.
¦ In use, the apparatus of Figure 1 has been found to provide a very
natural feeling which allows the musician to accurately compare his performance to
a pre-recorded track or other reference. This is believed to be due to the fact that
his performance, even though coupled through headphone speakers to his ears, is still t
electrically and spacially isolated from the pre-recorded or other audio signal. Thus,
the user is able to distinguish his performance from a reference signal better than if
the signals were electrically mixed as, for èxample, full quadraphonic sound with
¦ portions of each signal coupled to each of the speakers in both headphones. As a
¦ result, the user of the headphones is able to enjoy the privacy and other advantages
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5334 1 of heaclpl~ones witl)out losincr his ability to distinguish his performance from the
¦ reference signal. This result is accomplished Witll the use of equipment which is
~; simple nnd ine~;pensive when compared to typical studio mixing and amplifying
equipment.
¦ Xt can be seen that a group of musicians can practice together using
I the present invention without interfering with each other. Thus, each one can listen
¦ to a reference performance on inputs 26 while listening to his own performance by
inputs 32. In this way, neither the reference signal nor the practice performance
need be amplified through loudspeakers. An instructor may use the arrangement tolisten to one student's performance while comparing it to his own reference
performance without interference from the rest of the class.
j While the present invention has been described as having only two
¦¦ speakers in each earpiece, it is apparent that an additional speaker may be added to
each earpiece. The basic four speaker arrangement allows the musician to monitor a
-reference sterophonic source while listening to~his own performance QS a monaural
or even stereophonic si~nal. If it is desired to use a full quadraphonic source as a
reference, then four speakers, two in each earpiece, are needed to listen to the~; ¦ reference work. An additional speaker in each earpiece would then be used to
I monitor the musicians live perforrnance, again as either a monaural or stereophonic
2U ~ source. In this way, the electrical and spatial separations of the two signal sources
are maintained with the same benefits as found in the preferred embodiment.
While the present invention has been described in terms of particular
apparatus and methods used, it is apparent that various modifications and changes
cQn be made within the scope of the present invention as defined by the appendedclaims.
¦ I claim:
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