U.S. patent number 3,568,144 [Application Number 04/713,027] was granted by the patent office on 1971-03-02 for sound viewer apparatus.
This patent grant is currently assigned to Dewar Products Corp.. Invention is credited to Maria L. M. Streb.
United States Patent |
3,568,144 |
Streb |
March 2, 1971 |
SOUND VIEWER APPARATUS
Abstract
A sound viewer apparatus is described, including means for
receiving an audio signal and converting it into an electrical
signal, at least one amplifier for adjusting the intensity level of
the electrical signal; a plurality of filters, each having a
band-pass corresponding to the major frequency components of the
audio signal produced by a particular device (viz a car engine,
train whistle, horn or emergency vehicle siren); indicator means,
such as lamps, connected to the output of the filters; and
automatic gain control means responsive to the output of each
filter for adjusting the electrical signal input to the amplifier
for maintaining the input to the indicators at a level whereby the
indicator means (lamps) can clearly show, by relative brightness,
which type of device produced the audio sound and its relative
intensity.
Inventors: |
Streb; Maria L. M. (Rochester,
NY) |
Assignee: |
Dewar Products Corp.
(Rochester, NY)
|
Family
ID: |
24864467 |
Appl.
No.: |
04/713,027 |
Filed: |
March 14, 1968 |
Current U.S.
Class: |
340/901; 367/197;
340/815.69; 340/384.7 |
Current CPC
Class: |
B61L
29/246 (20130101); G10L 21/06 (20130101); G08B
1/08 (20130101); G08B 5/36 (20130101) |
Current International
Class: |
G08B
1/00 (20060101); G08B 1/08 (20060101); G10L
21/00 (20060101); G08B 5/22 (20060101); G10L
21/06 (20060101); B61L 29/24 (20060101); B61L
29/00 (20060101); G08B 5/36 (20060101); G08g
001/09 () |
Field of
Search: |
;340/33,34 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Habecker; Thomas B.
Claims
I claim:
1. A sound apparatus for a vehicle for visually warning the
presence of n different audio signals each of which have at least a
particular frequency characteristic of a sound producing device
comprising:
a. a transducer means for converting said n different audio signals
into corresponding electrical signal voltages having the same
corresponding frequencies as said audio signals;
b. filter means having n different filters each having a
predetermined band-pass for passing only those electrical signal
voltages having a frequency lying within said predetermined
band-pass therethrough;
c. a plurality of corresponding n indicator means coupled to said n
different filters for visually indicating the passage of said
electrical signal voltages therethrough so that the presence of
said audio signals is visually indicated thereby;
d. summing means connected to each of said n different filters for
deriving a rectified signal voltage which is a function of the sum
of said corresponding electrical signal voltages passed by said n
different filters; and
e. attenuation means connected between said transducer means and
said summing means for attenuating said corresponding electrical
signal voltages when said rectified signal voltage is higher than a
given reference voltage.
2. The invention defined in claim 1 wherein said attenuation means
includes variable resistor means for selectively varying said
reference voltage.
3. The invention defined in claim 1 wherein said attenuation means
includes a transistor having a base electrode connected to said
summing means for providing a low impedance switch between said
transducer means and ground.
4. The invention defined in claim 1 wherein said attenuation means
includes a transistor connected between ground and said transducer
means for attenuating said corresponding electrical signal voltages
to said indicator means in the same ratio as received by said
transducer.
5. The invention defined in claim 1 wherein said filters are active
band-pass filters.
6. The invention defined in claim 1 wherein said transducer means
is a microphone mounted on said vehicle for receiving said audio
signals outside of said vehicle.
7. The invention defined in claim 1 further including a plurality
of n gating means each connected between a corresponding one of
said filters and a corresponding one of said indicating means for
passing only said electrical signal voltages above a given voltage
level.
8. The invention defined in claim 1 wherein said summing means
includes diodes means connected to said filter means and a summing
resistor connected to said attenuation means for adjusting the
intensity of said output signal voltages from said transducer
means.
Description
The present invention relates to a sound discriminating apparatus
and more particularly to a sound viewer apparatus by which is meant
apparatus for monitoring audio signals such as a car engine, train
whistle, horn or emergency vehicle siren, and visually indicating
which of the signals is being received by the apparatus.
BACKGROUND OF THE INVENTION
The automotive industry has made great strides in improving driver
and passenger comfort by insulating the driver and passengers from
the effects of weather and outside noise. This is particularly
noted in the case of air conditioned vehicles where, from a
practical point of view, the car is generally sealed airtight.
Although these improvements are laudable, from a comfort point of
view, they create a safety hazard in that the driver and passengers
may not be able to hear an oncoming train or other vehicles.
Obviously, this problem is compounded in the case of
hard-of-hearing people, and in fact, may have disastrous
consequences at train crossings.
Recently enacted laws make it mandatory for motorcyclists to wear
helmets. Thus the cyclist is also faced with the came problem
mentioned heretofore. No known devices are available for cyclists
to detect warning signals.
In view of the foregoing, it is an object of the present invention
to provide a new sound viewer apparatus.
It is another object of the present invention to provide apparatus
which detects and indicates the types of ambient audio signals and
their relative intensity.
It is still another object of the present invention to provide
improved apparatus which permits a driver of an insulated vehicle
or a driver with a helmet to see by means of an indicator the
ambient noise being produced by devices such as a train, horn,
siren, etc.
In accordance with one embodiment of the invention, there is
provided a microphone which receives an audio signal and converts
it into an electrical signal which in turn, is routed to a
plurality of channels. Preferably each channel includes an
amplifier, a filter, the band-pass of which corresponds to the
major frequency band or signature of a particular audio producing
device; and an indicator lamp connected to each filter for
indicating which type of device produced the sound and its relative
intensity or nearness.
One important feature of this invention is the means for adjusting
the intensity of the input signal to the filters so that
differences in the relative output, brightness, or intensity of the
indicators or lamps may be easily distinguished when several
devices simultaneously produce a noise or audio signals.
Other objects and advantages of the present invention will become
apparent from the ensuing description of an illustrative embodiment
thereof in the course of which reference may be had to the
accompanying drawings in which:
FIG. 1 is a perspective view of an indicator means utilized in the
sound viewer apparatus of FIG. 2; and
FIG. 2 shows a preferred embodiment of the invention in schematic
view receiving an audio signal and visually displaying the signal
on the indicator means.
Turning to the drawing, a preferred embodiment of a sound viewer
apparatus 10 is shown to include a broad-band transducer 12 such as
a microphone, which receives an audio signal and produces an
electrical signal having the same or corresponding frequency
components found in the audio signal.
The transducer may be mounted on the roof of a vehicle or on the
handlebars of a motorcycle. It should be understood that more than
one transducer may be placed on the vehicle such as in the front
and rear without departing from the invention. The electrical
signal is applied as an input signal to a plurality of channels
a--n by way of a lead 13. The lead 13 is shown partly in dotted
line to indicate that there are a plurality of channels a--n, where
n is the last channel. Each channel a--n is similar in construction
and includes amplifying means for amplifying the input signal such
as corresponding controlled gain amplifiers 16 a--n.
It should be understood that the amplifying means may comprise a
single amplifier for amplifying the signal instead of n number of
amplifiers. This of course may be cheaper to make without departing
from the invention. The outputs of the amplifiers 16 a--n are
applied to the input of corresponding filters 17 a--n which may be
of the passive lumped constant variety in the audio range or of the
active-type filters having transistors or the like for passing a
particular frequency or pitch signature associated within the
band-pass of the corresponding filter. The output of each of the
filters 17 a--n is applied to corresponding driver amplifiers 22
a--n in the channels a--n respectively. The output of each of the
driver amplifiers 22 a--n is applied to corresponding indicators 20
a--n through threshold gates 24 a--n. The threshold gates 24 a--n
may be omitted if desired from each of the channels. However, it
may be desirable to include the threshold gates 24 a--n so that
only one of the indicators 20 a--n is energized when a signal above
a given voltage threshold is gated therethrough.
In accordance with the present invention, the band-pass of each
filter 17 a--n is selected for a predetermined frequency or pitch
signature. For example, the filter 17a may have a band-pass for a
train whistle (a high frequency band-pass) at a frequency fa while
the filters 17 b--n may have selected band-passes for a horn noise
and a siren. It should be noted that some audio signals carry other
frequencies and therefore may energize one or more lamps 20 a--n
with varying intensity.
The lamps 20 a--n may be slightly energized due to the fact that
some frequency components of a siren fb lie in the car horn's
frequency signature band fn. In order to prevent any ambiguity, the
aforesaid threshold gates 24 a--n may be coupled between the
drivers 22 a--n and the lamps 20 a--n so that a given signal above
a voltage threshold will energize a corresponding one of the lamps
20 a--n.
The indicators or lamps 20 a--n may be fixed in a housing 40 (FIG.
2) which includes transparent panels 41--43 upon which is engraved
the particular frequency upon which corresponding lamps 20 a--n are
energized as shown in FIG. 1. The transparent panels 41--43 may be
colored if desired to provide ready indication of the warning
signal, viz, siren, train whistle, car horn and the like. While
only three panels 41--43 are shown, it should be understood, of
course, that additional panels corresponding to the lamps 20 a--n
may be provided. The frame 40 may be mounted on a dashboard 44 of a
vehicle or on the handlebars of a motorcycle. The housing 40 may
also be mounted within the dashboard of a vehicle in a recess
provided therein.
The sound viewer apparatus 10 further includes summing means 25 for
summing the voltage output of each of the drivers 22 a--n. The
summing means 25 includes a plurality of rectifiers or diodes 26
a--n which rectifies the output of each of the drivers 22 a--n and
applies the output of the rectifier 26 a--n to a summing resistor
28. A DC blocking capacitor is provided at 30 between the output of
the diodes 26 a--n and ground. The rectified output from the
summing resistor 28 is applied to the base 32 of a transistor 33 in
an attenuator means or circuit 35. The transistor 33 provides a low
impedance gate between the output of the transducer 12 and ground
through the lead 13. A DC blocking capacitor 34 is provided between
the base 32 and ground. A variable resistor 36 is connected in
parallel with the gating transistor 32 for adjusting the
attenuation level of the attenuator circuit 35. A capacitor 37 is
connected in series with the resistor 36 and the transistor 33.
Different sound producing devices develop characteristic sounds
having most of their high intensity frequency components in
different pitch or frequency bands. A siren, for example, will
produce most of its higher intensity components at a higher
frequency than will the noise produced by a running motor, horn or
train whistle. Each type of sound emitting device can be thought of
as having a frequency or pitch signature associated with some
frequency band.
In the operation of the sound viewer apparatus 10, assuming a siren
signal is received by the transducer 12, the siren signal is
converted into a corresponding electrical signal having a
corresponding frequency. The electrical signal is amplified and
applied to each of the channels a--n. The siren signal passes
through the assigned filter 17b while all other filters block the
signal. The signal is then amplified and passed to the indicator or
lamp 20b. In response to the signal the lamp 20b is energized and
panel 42 is illuminated. The signal is also rectified by the diode
26b and the output is applied to the summing resistor 28 and then
to the base 32 of the transistor 33 in the attenuator circuit 35.
If the rectified signal has a high DC potential or is higher than a
reference voltage, the normally closed or back-biased transistor 33
is turned on to provide a low impedance circuit between the
transducer 12 and ground to thus decrease the signal output of the
transducer. This is particularly important since some received
signals may carry frequencies which may be passed by the other
filters 17 a--n and thus energize some of the lamps 20 a--n to a
lesser degree. By summing the DC output of the filters 17 a--n in
the means 25 and applying the summed output to the attenuator
circuit 35, the relative intensity of the lamps 20 a--n is
maintained even for a very strong signal which may have different
frequency components since part of the signal is shunted to ground
by the transistor 33. By maintaining the relative strength of the
signal by the means 25 and attenuator circuit 35, the threshold
gates may thus pass only the desired highest strength signals from
the filters 17 a--n and thus only those signals above a given
voltage level will energize the lamps 20 a--n. The sound viewer
apparatus also operates in the same manner for other received
signals viz the train whistle and horn described herein.
While there has been shown and described what is considered at
present to be the preferred embodiment of the invention,
modifications thereto will readily occur to those skilled in the
art. For example, the indicators 20 a--n may be other alarm devices
such as horns instead of lamps or may in fact be a combination of
both. It is not desired, therefore, that the invention be limited
to the embodiment shown and described, and it is intended to cover
in the appended claims all such modifications as fall within the
true spirit and scope of the invention.
* * * * *