[0001] The present invention relates to methods and apparatus for processing sound signals,
preferably to a method of processing a sound signal in which background interference
of the sound signal is eliminated, so as to process only a signal from a sound source
for amplification.
[0002] A conventional method of eliminating interference employs a filter for processing
a voltage or current signal through a filtering circuit, in a manner as to allow the
signal having a frequency above or below a certain frequency or within a certain frequency
range to pass through the circuit, so as to distinguish the signal into a desired
signal and an interfering signal. In view of operational principles, such a general
filter includes a low pass filter, a high pass filter, a band pass filter and an off-band
pass filter. Such a filter allows a signal to be input to a circuit thereof and processes
the signal to be differentiated into interference and a desired signal according to
characteristics such as signal amplitude and frequency.
[0003] In a conventional sound signal processing system such as the one disclosed in Kroschel
("Methods for Noise Reduction Applied to Speech Input Systems", Compeuro '89, pp.
2-82 - 2-87), there is usually a pre-processing unit used to preprocess the input
signals, such as amplification, time-delay compensation or beamforming, then the signals
are fed into a noise reduction unit used to eliminate the interference.
[0004] In the conventional technology, a signal cannot be pre-separated into a desired component
and an interfering component without being entirely processed by a filter.
[0005] The present invention seeks to provide improved sound signal processing.
[0006] According to an aspect of the present invention, there is provided a method of processing
a sound signal as specified in claim 1.
[0007] According to another aspect of the present invention, there is provided a sound signal
processing system as specified in claim 3.
[0008] In the preferred embodiment, after the sound signal is distinguished into a sound
source signal and background interference, the background interference is eliminated
and only the sound source signal is processed.
[0009] The preferred embodiment provides a method of processing a sound signal, which is
applied to a signal processing system including a signal receiving device, a signal
recognising device and a signal processing device, so as to eliminate background interference
and only process a sound source signal for amplification, according to phase change
and deviation of the sound signal, intensity of signal amplitude, and frequency change
caused by the Doppler effect.
[0010] In accordance with this, the preferred method, which is applied to a signal processing
system including a signal receiving device, a signal recognising device and a signal
processing device, includes the following steps.
[0011] First, the signal receiving device having a left receiving element and a right receiving
element receives a signal containing a sound source signal and background interference,
or selectively receives a sound signal from a particular direction by adjusting the
left and right receiving elements.
[0012] Then, the signal recognising device distinguishes the received sound signal into
the sound source signal and the background interference, which differ from each other
in characteristics such as phase, amplitude and frequency. Therefore, the signal recognising
device makes use of phase change and deviation of the sound signal, intensity of signal
amplitude, and frequency change caused by Doppler effect, so as to differentiate the
sound source signal from the background interference.
[0013] After the sound source signal and the background interference are separated from
each other, the signal recognising device eliminates the background interference and
simply transfers the sound source signal to the signal processing device.
[0014] Upon receiving the sound source signal, the signal processing device processes the
sound source signal for amplification, and thus no filtering circuit is required for
the elimination of the background interference.
[0015] Embodiments of the present invention are described below, by way of example only,
with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram of basic system architecture for a preferred embodiment
of signal processing system;
FIG. 2 is a schematic diagram showing the steps involved in eliminating background
interference and only amplifying a sound source signal in the signal processing system
of FIG. 1;
FIG. 3 is a schematic diagram showing the steps involved in determining phase change
and deviation of a sound signal for eliminating background interference and only amplifying
a sound source signal in an embodiment of the signal processing system of FIG. 1;
FIG. 4 is a schematic diagram showing the steps involved in determining amplitude
of a sound signal for eliminating background interference and only amplifying a sound
source signal in another embodiment of the signal processing system of FIG. 1; and
FIG. 5 is a schematic diagram showing the steps involved in determining frequency
change caused by Doppler effect for eliminating background interference and only amplifying
a sound source signal in a further embodiment of the signal processing system of FIG.
1.
[0016] Illustrated in FIG. 1 is basic system architecture for a signal processing system
in the use of the preferred method of processing a sound signal. As shown in FIG.
1, the signal processing system 1 includes a signal receiving device 11, a signal
recognising device 12 and a signal processing device 13, wherein the signal receiving
device 1 1 is coupled to the signal recognising device 12, which is further coupled
to the signal processing device 13.
[0017] The signal receiving device 11 has a left receiving element 111 and a right receiving
element 112, so as to receive a sound signal containing a sound source signal and
background interference, or selectively to receive a sound signal from a particular
direction by adjusting the left and right receiving elements 111, 112. The signal
receiving device 11 transfers the received sound signal to the signal recognising
device 12, which is used to distinguish the received sound signal into the sound source
signal and the background, according to phase change and deviation of the sound signal,
intensity of signal amplitude, and frequency change caused by the Doppler effect.
The signal recognising device 12 then eliminates the background interference and transfers
only the sound source signal to the signal processing device 13. Subsequently, the
sound source signal is processed by the signal processing device 13 for amplification
and thus it is not necessary to employ a filtering circuit for eliminating the background
interference.
[0018] FIG. 2 illustrates the steps involved in using the preferred method of processing
a sound signal for the signal processing system of FIG. 1.
[0019] As shown in the drawing, first in step 2, the signal receiving device 11 having the
left receiving element 111 and the right receiving element 112 receives a signal containing
a sound source signal and background interference, or selectively receives a sound
signal from a particular direction by adjusting the left and right receiving elements
111, 112. Then, step 3 is followed.
[0020] In step 3, the signal recognising device 12 distinguishes the received sound signal
into the sound source signal and the background interference, which differ from each
other in characteristics such as phase, amplitude and frequency. Therefore, the signal
recognising device 12 makes use of phase change and deviation of the sound signal,
intensity of signal amplitude and frequency change caused by the Doppler effect, so
as to differentiate the sound source signal from the background interference.
[0021] In step 4, after the sound source signal and the background interference are separated
from each other, the signal recognising device 12 eliminates the background interference
and transfers only the sound source signal to the signal processing device 13. Then
step 5 is followed.
[0022] In step 5, upon receiving the sound source signal, the signal processing device 13
processes the sound source signal for amplification, without using a filtering circuit
for eliminating the background interference.
[0023] FIG. 3 illustrates the steps involved in determining phase change and deviation of
a sound signal for eliminating background interference and amplifying only a sound
source signal in an embodiment of the signal processing system of FIG. 1.
[0024] First, in step 21, the signal receiving device 11 having the left receiving element
111 and the right receiving element 112 receives a signal containing a sound source
signal and background interference, or selectively receives a sound signal from a
certain (particular) direction by adjusting the left and right receiving elements
111,112 according to phase difference for the received sound signal (for example,
phase lead or delay). Then step 22 is followed.
[0025] In step 22, the signal recognising device 12 distinguishes the received sound signal
into the sound source signal and the background interference in response to phase
difference therebetween. Therefore, the signal recognising device 12 makes use of
phase change and deviation of the sound signal so as to differentiate the sound source
signal from the background interference.
[0026] In step 23, after the sound source signal and the background interference are separated
from each other, the signal recognising device 12 eliminates the background interference
and transfers only the sound source signal to the signal processing device 13. Then
step 24 is followed.
[0027] In step 24, upon receiving the sound source signal, the signal processing device
13 processes the sound source signal for amplification, without using a filtering
circuit for eliminating the background interference.
[0028] FIG. 4 illustrates the steps involved in determining amplitude of a sound signal
for eliminating background interference and amplifying only a sound source signal
in another embodiment of the signal processing system of FIG. 1.
[0029] First, in step 31, the signal receiving device 11 having the left receiving element
111 and the right receiving element 112 receives a signal containing a sound source
signal and background interference, or selectively receives a sound signal from a
particular direction by adjusting the left and right receiving elements 111, 112.
Then step 32 is followed.
[0030] In step 32, the signal recognising device 12 distinguishes the received sound signal
into the sound source signal and the background interference in response to amplitude
difference therebetween. Therefore, the signal recognising device 12 makes use of
intensity of signal amplitude so as to differentiate the sound source signal from
the background interference.
[0031] In step 33, after the sound source signal and the background interference are separated
from each other, the signal recognising device 12 eliminates the background interference
and transfers only the sound source signal to the signal processing device 13. Then
step 34 is followed.
[0032] In step 34, upon receiving the sound source signal, the signal processing device
13 processes the sound source signal for amplification, without using a filtering
circuit for eliminating the background interference.
[0033] FIG. 5 illustrates the steps involved in determining frequency change caused by the
Doppler effect for eliminating background interference and amplifying only a sound
source signal in another embodiment of the signal processing system of FIG. 1.
[0034] First, in step 41, the signal receiving device 1 1 having the left receiving element
111 and the right receiving element 112 receives a signal containing a sound source
signal and background interference, or selectively receives a sound signal from a
particular direction by adjusting the left and right receiving elements 111, 112.
Then step 42 is followed.
[0035] In step 42, the signal recognising device 12 distinguishes the received sound signal
into the sound source signal and the background interference in response to velocity
difference therebetween. Therefore, the signal recognising device 12 makes use of
frequency change caused by the Doppler effect so as to differentiate the sound source
signal from the background interference.
[0036] In step 43, after the sound source signal and the background interference are separated
from each other, the signal recognising device 12 eliminates the background interference,
and transfers only the sound source signal to the signal processing device 13. Then
step 44 is followed.
[0037] In step 44, upon receiving the sound source signal, the signal processing device
13 processes the sound source signal for amplification, without using a filtering
circuit for eliminating the background interference.
[0038] In conclusion, the methods for processing a sound signal described above are applied
to the signal processing system including the signal receiving device, the signal
recognising device and the signal processing device, in which the signal recognising
device is used to distinguish the sound signal received from the signal receiving
device into a sound source signal and background interference. In this case, the signal
processing device processes and amplifies only the sound source signal and thus no
filtering circuit is required for the elimination of the background interference.
[0039] The invention has been described using exemplary preferred embodiments. However,
it is to be understood that the scope of the invention is not limited to the disclosed
embodiments. On the contrary, it is intended to cover various modifications and similar
arrangements. The scope of the invention is limited by the appended claims only.
1. . A method of processing a sound signal, applied to a signal processing system including
a signal receiving device (11), a signal recognising device (12) and a signal processing
device (13), so as to eliminate background interference and process a sound source
signal for the sound signal; the method including the steps of:
(1) receiving (2, 21, 31, 41) a sound signal containing a sound source signal and
background interference via the signal receiving device (11);
(2) distinguishing (3, 22, 32, 42) the sound signal into the sound source signal and
the background interference via the signal recognising device (12) according to signal
phase difference, difference in signal amplitude intensity, and frequency change caused
by the Doppler effect;
(3) substantially eliminating (4) 23, 33, 43) the background interference and transferring
substantially only the sound source signal via the signal recognising device (12)
to the signal processing device (13); and
(4) processing and amplifying (5) 24, 34, 44) the sound source signal via the signal
processing device (13) free of using a filtering circuit.
2. A method according to claim 1, wherein the receiving step includes adjusting the signal
receiving device (11) so as to receive selectively a sound signal containing a sound
source signal and background interference from a certain direction via the signal
receiving device (11).
3. A sound signal processing system including a signal receiving device (11), a signal
recognising device (12) and a signal processing device (13) and designed substantially
to eliminate background interference and to process a sound source signal for the
sound signal; wherein:
(1) the signal receiving device (11) is operable to receive a sound signal containing
a sound source signal and background interference;
(2) the signal recognising device (12) is operable to distinguish the sound signal
into the sound source signal and background interference according to signal phase
difference, difference in signal amplitude intensity, and frequency change caused
by the Doppler effect;
(3) the signal recognising device (12) and the signal processing device (13) are operable
substantially to eliminate background interference and to transfer substantially only
the sound source signal; and
(4) the signal processing device (13) is operable to process and amplify the sound
source signal free of using a filtering circuit.
4. A sound signal processing system according to claim 3, wherein the signal receiving
device (11) is adjustable so as to receive selectively a sound signal containing a
sound source signal and background interference.
1. Verfahren zur Verarbeitung eines Klangsignals, angewandt auf ein Signalverarbeitungssystem
mit einer Signalempfangseinrichtung (11), einer Signalerkennungseinrichtung (12) und
einer Signalverarbeitungseinrichtung (13), um Hintergrundinterferenzen zu eliminieren
und ein Klangquellensignal für das Klangsignal zu verarbeiten; wobei das Verfahren
die Schritte umfasst:
(1) Aufnehmen (2, 21, 31, 41) eines Klangsignals, das ein Klangquellensignal und eine
Hintergrundinterferenz enthält, mittels der Signalempfangseinrichtung (11);
(2) Unterscheiden (3, 22, 32, 42) des Klangsignals in das Klangquellensignal und die
Hintergrundinterferenz mittels der Signalerkennungseinheit (12) gemäß einer Signalphasendifferenz,
einer Differenz in der Signalamplitudenstärke und einer Frequenzänderung, die durch
den Dopplereffekt verursacht ist;
(3) im Wesentlichen Eliminieren (4, 23, 33, 43) der Hintergrundinterferenz und Übertragen
im Wesentlichen nur des Klangquellensignals mittels der Signalerkennungseinrichtung
(12) auf die Signalverarbeitungseinrichtung (13); und
(4) Verarbeiten und Verstärken (5, 24, 34, 44) des Klangquellensignals mittels der
Signalverarbeitungseinrichtung (13) ohne Verwendung einer Filterschaltung.
2. Verfahren nach Anspruch 1, wobei der Aufnahmeschritt ein Anpassen der Signalempfangseinrichtung
(11) umfasst, um selektiv ein Klangsignal zu empfangen, das ein Klangsignal und eine
Hintergrundinterferenz aus einer bestimmten Richtung enthält, mittels der Signalempfangseinrichtung
(11).
3. Klangssignalverarbeitungssystem mit einer Signalempfangseinrichtung (11), einer Signalerkennungseinrichtung
(12) und einer Signalverarbeitungseinrichtung (13), das im Wesentlichen dafür bestimmt
ist, Hintergrundinterferenzen zu eliminieren und ein Klangquellensignal für das Klangssignal
zu verarbeiten; wobei:
(1) die Signalempfangseinrichtung (11) zum Empfangen eines Klangsignals betreibbar
ist, das ein Klangquellensignal und eine Hintergrundinterferenz enthält;
(2) die Signalerkennungseinrichtung (12) betreibbar ist, um das Klangssignal in das
Klangquellensignal und Hintergrundinterferenz gemäß einer Signalphasendiffer,enz,
einer Differenz in der Signalamplitudenstärke und einem Frequenzwechsel, einer Differenz
in der Signalamplitudenstärke und einer Frequenzänderung, verursacht durch den Dopplereffekt,
zu unterscheiden;
(3) die Signalerkennungseinrichtung (12) und die Signalverarbeitungseinrichtung (13)
betreibbar sind, um im Wesentlichen Hintergrundinterferenzen zu eliminieren und im
Wesentlichen nur das Klangquellensignal zu übertragen; und
(4) die Signalverarbeitungseinrichtung (13) betreibbar ist, um das Klangssignal zu
verarbeiten und zu verstärken ohne Verwendung einer Filterschaltung.
4. Klangsignalverarbeitungssystem nach Anspruch 3, wobei die Signalempfangseinrichtung
(11) anpassbar ist, um selektiv ein Klangsignal zu empfangen, das ein Klangquellensignal
und Hintergrundinterferenz enthält.
1. Procédé de traitement d'un signal sonore, appliqué à un système de traitement de signal
comportant un dispositif de réception de signal (11), un dispositif de reconnaissance
de signal (12) et un dispositif de traitement de signal (13), de manière à éliminer
les interférences de fond et à traiter un signal de source sonore pour le signal sonore
; le procédé comprenant les étapes de :
(1) réception (2, 21, 31, 41) d'un signal sonore contenant un signal de source sonore
et une interférence de fond par l'intermédiaire du dispositif de réception de signal
(11) ;
(2) séparation (3, 22, 32, 42) du signal sonore en le signal de source sonore et l'interférence
de fond par l'intermédiaire du dispositif de reconnaissance de signal (12) en fonction
du déphasage de signal, de la différence d'intensité ou amplitude de signal et de
la variation de fréquence provoquée par l'effet Doppler;
(3) élimination substantielle (4, 23, 33, 43) de l'interférence de fond et transfert
presque uniquement du signal de source sonore par l'intermédiaire du dispositif de
reconnaissance de signal (12) au dispositif de traitement de signal (13) ; et
(4) traitement et amplification (5, 24, 34, 44) du signal de source sonore par l'intermédiaire
du dispositif de traitement de signal (13) sans utiliser de circuit de filtrage.
2. Procédé selon la revendication 1, dans lequel l'étape de réception comporte le réglage
du dispositif de réception de signal (11) afin de recevoir de manière sélective un
signal sonore contenant un signal de source sonore et des interférences de fond à
partir d'une certaine direction par l'intermédiaire du dispositif de réception de
signal (11).
3. Système de traitement de signal comportant un dispositif de réception de signal (11),
un dispositif de reconnaissance de signal (12) ainsi qu'un dispositif de traitement
de signal (13), et conçu de manière à éliminer sensiblement toute interférence de
fond et à traiter un signal de source sonore pour le signal sonore ; dans lequel :
(1) le dispositif de réception de signal (11) peut être commandé afin de recevoir
un signal sonore contenant un signal de source sonore et des interférences de fond
;
(2) le dispositif de reconnaissance de signal (12) peut être commandé de manière à
séparer le signal sonore en le signal de source sonore et les interférences de fond
en fonction du déphasage de signal, de la différence d'intensité ou amplitude de signal
et de la variation de fréquence provoquée par l'effet Doppler ;
(3) le dispositif de reconnaissance de signal (12) et le dispositif de traitement
de signal (13) peuvent être commandés afin d'éliminer pratiquement toute interférence
de fond et de ne transférer presque uniquement que le signal de source sonore ; et
(4) le dispositif de traitement de signal (13) peut être commandé afin de traiter
et d'amplifier le signal de source sonore sans utiliser de circuit de filtrage.
4. Dispositif de traitement de signal sonore selon la revendication 3, dans lequel le
dispositif de réception de signal (11) peut être réglé afin de recevoir de manière
sélective un signal sonore contenant un signal de source sonore et des interférences
de fond.