U.S. patent application number 09/771055 was filed with the patent office on 2001-06-21 for musical sound signal generation apparatus.
Invention is credited to Matsuda, Eiji, Saito, Tsutomu, Tanaka, Jiro.
Application Number | 20010003943 09/771055 |
Document ID | / |
Family ID | 27460260 |
Filed Date | 2001-06-21 |
United States Patent
Application |
20010003943 |
Kind Code |
A1 |
Matsuda, Eiji ; et
al. |
June 21, 2001 |
Musical sound signal generation apparatus
Abstract
A musical sound signal generation apparatus for producing a
sound corresponding to an operated key can produce a sound of a
newly-operated key even if all the musical sound signal generation
means for generating a musical sound signal are in use. On
producing the new sound, the apparatus prevents the players and the
audience from having a sense of incongruity derived from the change
in sound production. Especially, when a chord has been produced, it
can maintain the state of chord production normally.
Inventors: |
Matsuda, Eiji;
(Shizuoka-ken, JP) ; Tanaka, Jiro; (Shizuoka-ken,
JP) ; Saito, Tsutomu; (Shizuoka-ken, JP) |
Correspondence
Address: |
DAVIS & BUJOLD, P.L.L.C.
500 NORTH COMMERCIAL STREET
FOURTH FLOOR
MANCHESTER
NH
03101
US
|
Family ID: |
27460260 |
Appl. No.: |
09/771055 |
Filed: |
January 26, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09771055 |
Jan 26, 2001 |
|
|
|
09504647 |
Feb 14, 2000 |
|
|
|
6198035 |
|
|
|
|
Current U.S.
Class: |
84/615 |
Current CPC
Class: |
G10H 7/02 20130101; G10H
1/186 20130101; G10H 2210/305 20130101 |
Class at
Publication: |
84/615 |
International
Class: |
G10H 001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 1999 |
JP |
11-36423 |
Feb 17, 1999 |
JP |
11-38785 |
Mar 22, 2000 |
JP |
2000-80116 |
Claims
What is claimed is:
1. A musical sound signal generation apparatus comprising: a
plurality of musical sound signal generation means for generating
musical sound signals; a generation mode storage means for storing
information on whether said musical sound signal generation means
is in the sounding mode or the silent mode, and the order in which
each of the musical sound signal generation means has changed into
the sounding mode; an assigning means for, when a key is operated,
referring to storage contents of said generation mode storage means
to select two of said musical sound signal generation means in the
silent mode, directing the selected two musical sound signal
generation means to respectively generate left and right musical
sound signals for producing a predetermined sound in stereo
sounding corresponding to the key in the selected two musical sound
signal generation means, and updating the storage contents of the
generation mode storage means; and output means for synthesizing
the left and right musical sound signals generated in said
plurality of musical sound signal generation means and respectively
outputting the synthesized left and right musical sound signals;
wherein said assigning means comprises: a first generation mode
determination means for, when the key is operated, referring to the
storage content of said generation mode storage means to determine
whether there are musical sound signal generation means in the
silent mode; a second generation mode determination means for, in
case of which it is determined by said first generation mode
determination means that there are no musical sound signal
generation means in the silent mode, referring to the storage
contents of said generation mode storage means, and, from the
musical sound signal generation means excluding a predetermined
number of those which are the newest in order of sound production,
determining whether there are at least two pairs of the musical
sound signal generation means generating the left and right musical
sounds in stereo sounding; a first signal generation ensuring means
for, in case of which it is determined by said second generation
mode determination means that there are two or more pairs of said
musical sound signal generation means, selecting two pairs of the
musical sound signal generation means, changing one of each pair of
the musical sound signal generation means into the silent mode, and
updating the storage contents of said generation mode storage
means; and output control means for outputting musical sound
signals generated in the other two musical sound signal generation
means, not changed into the silent mode by said first signal
generation securing means, as the left and right musical sound
signals from each of the two musical sound signal generation
means.
2. A musical sound signal generation apparatus according to claim
1, wherein said allocation means comprises a second signal
generation ensuring means for, in case of which it is determined by
said second generation mode determination means that at least two
pairs of said musical sound signal generation means generating left
and right musical sound signals in stereo sounding do not exist,
changing the oldest two musical sound signal generation means in
order of sound production into the silent mode and updating the
stored contents of said generation mode storage means.
3. A musical sound signal generation apparatus according to claim
1, wherein said output control means comprises a correction panning
means for performing a panning processing to a musical sound signal
to be outputted simultaneously from both left and right sides of
said output means so that a predetermined sound image is obtained
corresponding to an operated key.
4. A musical sound signal generation apparatus according to claim
1, wherein said output control means further comprises a volume
correction means for adjusting an outputting volume of a musical
sound signal to be outputted simultaneously from both left and
right sides of said output means so that a predetermined sound
image is obtained corresponding to an operated key.
Description
[0001] This is a continuation-in-part of a co-pending application
Ser. No. 09/504,647 filed Feb. 14, 2000 and entitled "Musical Sound
Signal Generation Apparatus".
FIELD OF THE INVENTION
[0002] This invention relates to a musical sound signal generation
apparatus for generating a sound corresponding to an operated key,
more particularly to an apparatus for, when a plurality of keys are
simultaneously depressed, generating musical sounds corresponding
to each key.
BACKGROUND OF THE INVENTION
[0003] An electronic instrument as typified by an electronic piano
conventionally includes a pair of musical sound signal generation
means for generating two musical sound signals for one key
operation (key-on) for stereo performance. If such pair of musical
sound signal generation means are provided as much as the number of
the keys, musical sound signals for sound production can be
securely generated. However, the increase in number of the musical
sound signal generation means accompanies the increase in costs as
well.
[0004] Therefore, the applicant has developed a musical sound
signal generation apparatus to effectively utilize the musical
sound signal generating means as disclosed in the Unexamined
Japanese Patent Publication No 10-49159. Teaching of this
Publication is that if a new key-on is made when all the musical
sound generation means are in use, two pairs of the oldest musical
sound signal generation means in order of sound production are
selected from all the musical sound signal generation means in the
sounding mode, and one of the musical sound signal generation means
constituting each pair is truncated (rapidly attenuated), while the
remaining musical sound signal generation means operate as they are
Thereby, since two musical sound signal generation means are
changed into the silent mode (become free), they can be reused as
the musical sound signal generation means for generating musical
sound signals in stereo sounding, corresponding to a fresh
key-on.
[0005] However, in case of the musical sound signal generation
apparatus of the above Publication, when all of the musical sound
signal generation means are in use and that the oldest musical
sound signal generation means in order of sound production is
generating one of the musical sound signals which constitute a
chord (for example, a chord consisting of 3 or 4 different tones),
if this musical sound signal generation means is silenced and
reused as the musical sound signal generation means for stereo
sounding corresponding to a fresh key-on, there is a fear that the
players and/or the audience may feel uncomfortable for lack of the
sound in the chord.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is, in a musical sound
signal generation apparatus for producing a sound corresponding to
an operated key, even though musical sound signal generation means
for generating a musical sound signal are all in use, to secure
musical sound signal generation means for sound production
corresponding to a newly operated key, and when securing the
musical sound signal generation means, to prevent the players
and/or the audience from having a sense of incongruity derived from
the change in sound production, especially when a chord is being
produced, to maintain the state of the chord production
normally.
[0007] To attain the above object, the fist aspect of the present
invention provides a musical sound signal generation apparatus
comprising a plurality of musical sound signal generation means and
a generation mode storage means. The musical sound signal
generation means generate musical sound signals, and the generation
mode storage means stores information on whether the musical sound
signal generation means are in the sounding mode or in the silent
mode, and the order in which each of the musical sound signal
generation means has changed into the sounding mode.
[0008] The musical sound signal generation apparatus further
comprises an assigning means and output means. When a key is
operated, the assigning means refers to storage contents of the
generation mode storage means to select two of the musical sound
signal generation means in the silent mode, assigns the selected
two musical sound signal generation means to generate left and
right musical sound signals for producing a predetermined sound in
stereo sounding corresponding to the key in the selected two
musical sound signal generation means, and updating the storage
contents of the generation mode storage means Then, the output
means synthesize the left and right musical sound signals generated
in the plurality of musical sound signal generation means and
respectively output the synthesized left and right musical sound
signals.
[0009] Specifically, the assigning means of the musical sound
signal generation apparatus of the present invention is provided
with a first generation mode determination means, a second
generation mode determination means, a first signal generation
ensuring means and output control means, which operate as
follows.
[0010] When a key is operated, the first generation mode
determination means refers to the storage contents of the
generation mode storage mean to determine whether there are musical
sound signal generation means in the silent mode. When no musical
sound signal generation means in the silent mode exist, the second
generation mode determination means refers to the storage contents
of the generation mode storage means, and from the musical sound
signal generation means excluding a predetermined number of those
which are the newest in order of sound production, determines
whether there are at least two pairs of the musical sound signal
generation means generating left and right musical sound signals in
stereo sounding.
[0011] When two or more pairs of the musical sound signal
generation means generating left and right musical sound signals in
stereo sounding exist, the first signal generation ensuring means
arbitrarily selects two pairs of the musical sound signal
generation means from those in stereo sounding, changes one of each
pair of the musical sound signal generation means into the silent
mode, and updates the storage contents of the generation mode
storage means. The output control means output musical sound
signals generated in the other one of each pair of the musical
sound signal generation means as left and right musical sound
signals from each of the two musical sound signal generation
means.
[0012] Accordingly, when a key is operated, even though the
plurality of the musical sound signal generation means are all in
use (that is, generating musical sound signals), by selecting two
pairs of the musical sound signal generation means and silencing
one of each pair of the musical sound signal generation means, the
musical sound signal generation apparatus of the present invention
can secure two musical sound signal generation means in the silent
mode as those for stereo sounding corresponding to the key.
[0013] Additionally, since the musical sound signal generation
means to be silenced are arbitrarily selected from the same
excluding a predetermined number of those which are the newest in
order of sound production, it is possible to prevent the players
and the audience from having a sense of incongruity caused by
silencing a sound of the key just operated. Thereby, when all the
musical sound signal generation means are changed into the sounding
mode upon the production of a chord and then another key is further
operated, for example, the sound of the key operated prior to the
chord is silenced and the chord reaches the ears of the players and
the audience without being deteriorated This means that it is
difficult for the players and the audience to recognize the fact
that the sound of the key previously operated has been
silenced.
[0014] Specifically, if the musical sound signal generation meant
which are not generating musical sound signals for a chord are
given precedence in arbitrary selection of the musical sound signal
generation means to be silenced, it is possible to keep the state
of the chord production normal at every moment.
[0015] In the two musical sound signal generation means maintained
without being silenced, the generated musical sound signals are
outputted as both left and right musical sound signals respectively
so that the musical sound signals to be outputted from the output
means may be produced in "monaural sounding". Thereby, the output
means can maintain the balance of the left and right sounds upon
outputting them.
[0016] Meanwhile, in the musical sound signal generation apparatus
of the present invention, when all the musical sound signal
generation means are in use and keys are operated one after
another, all the musical sound signal generation means, excluding
the predetermined number of those which are the newest in order of
sound production, may generate the musical sound signals in
"monaural sounding".
[0017] Accordingly, the second aspect of the present invention
provides the assigning means comprising a second signal generation
securing means for, in case that at least two pairs of the musical
sound signal generation means generating left and the right musical
sound signals in stereo sounding do not exist, silencing two of the
oldest musical sound signal generation means in order of sound
production and updating the storage contents of the generation mode
storage means.
[0018] With such constitution, even if all the musical sound signal
generation means excluding the predetermined number are generating
the musical sound signals in "monaural sounding", by changing two
of the musical sound signal generation means in monaural sounding
into the silent mode, the two musical sound signal generation means
can be secured for musical sound signal generation means for stereo
sounding corresponding to a fresh key. In addition, because the
musical sound signal generation means to be silenced are selected
from those of the oldest in order of sound production, the players
and the audience are not given a sense of incongruity occurred by
silencing a sound of the key just operated.
[0019] Meanwhile, the two musical sound signal generation means not
silenced by the fist signal generation securing means are changed
into monaural sounding from stereo sounding, by outputting the
musical sound signals as left and right musical sound signals from
each of the musical sound signal generation means. When the musical
sound signal generation means are in monaural sounding, it is
necessary to avoid giving a sense of incongruity derived from the
change in sound production to the players and the audience.
[0020] The third and fourth aspects of the present invention
provide the output control means comprising a correction panning
means for performing a panning processing and a volume correction
means for adjusting the outputting volume of musical sound signals
to be outputted simultaneously from both the left and right output
means, respectively, so that a predetermined sound image is
obtained corresponding to the operated key. With such constitution,
for example, if the operated key is located on the side of the
higher notes, then by relatively increasing a panning value or the
volunteer of the right output, or if the key is on the side of the
lower notes, then by relatively increasing the panning value or the
volume of the left output, a pseudo-stereo effect can be
obtained.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0021] The invention will now be described in detail with reference
to the accompanying drawings, in which:
[0022] FIG. 1 is a block diagram showing the entire constitution of
a musical sound signal generation apparatus of an embodiment;
[0023] FIG. 2 is a block diagram showing the entire constitution of
the musical sound signal generation apparatus of the
embodiment;
[0024] FIG. 3 is an explanatory view showing various information
areas provided in a CPU work RAM of the musical sound signal
generation apparatus of the embodiment;
[0025] FIG. 4 is a flow chart showing a main processing executed by
a CPU of the musical sound signal generation apparatus of the
embodiment;
[0026] FIG. 5 is a flow chart showing a key assignment processing
executed by the CPU of the musical sound signal generation
apparatus of the embodiment; and
[0027] FIGS. 6 is a flow chart showing a sound channel acquisition
processing executed by the CPU of the musical sound signal
generation apparatus of the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] A musical sound signal generation apparatus of the present
embodiment is incorporated into a keyboard type electronic
instrument and used for outputting musical sounds.
[0029] As shown in FIG. 1, an electronic instrument 10 according to
an embodiment of the present invention comprises a CPU 12, a CPU
program ROM 14, a tone parameter ROM 16, a CPU work RAM 18, a panel
20, a keyboard 26, a musical sound signal generation circuit 40 and
a bus line 30 which connects all of the above-mentioned components.
Since a serial input/output circuit 32 is connected to the bus line
30, the electronic instrument 10 can also produce musical sounds by
means of MIDI signals inputted externally to the serial
input/output circuit 32, in addition to the production of the
musical sounds by operations (i.e. key-on or key-off) on the
keyboard 26,
[0030] The control processing for producing a musical sound is
performed as follows. A control program for generating a musical
sound is stored in the CPU program ROM 14. According to the control
program, the CPU 12 scans the keyboard 26 to read the performance
information, such as a key-on/key-off, a key number and touch
information. It then assigns a channel (musical sound generation
channel) for generating a digital musical sound signal in the
musical sound signal generation circuit 40, scans the panel 20 to
read the operation mode of various switches provided on the panel
20, and finally conducts sound production control of the musical
sound generation channel.
[0031] In the tone parameter ROM 16, stereo tone parameters and
monaural tone parameters are stored. Each tone parameter includes
attack, decay and release envelope data, a wave start address, and
L and R panning coefficients. For the stereo tone parameters, the
envelope data, wave start address and L and R panning coefficients
are provided in pair of L side and R side, and for the monaural
tone parameters, the envelope data, wave start address and L and R
panning coefficients are provided in L/R common.
[0032] The panning coefficient is a parameter to be used in a
panning process performed in the musical sound signal generation
circuit 40, which will be described later, and it changes a ratio
of left and right musical sound volumes corresponding to the key
number (i.e. position of the pressed key on the keyboard 26)
directed by the CPU 12. For example, if the key number indicates
the key on the right-of-center side of the keyboard 26, the larger
volume is set to the right system than the volume set to the left
system. On the contrary if the key number indicates the key on the
left-of-center side of the keyboard 26, the larger volume is set to
the left system than the volume set to the right system.
[0033] In the present embodiment, the panning coefficients are set
between numerical values from 0 to 100. In the stereo tone
parameters, the L panning coefficient on the L side is set to 70,
and the R panning coefficient on the L side is set to 0, for each
of the low, medium, and high tones. Conversely, the D panning
coefficient on the R side is set to 70, and the L panning
coefficient on the R side is set to 0, for each of the low, medium,
and high tones. Accordingly, because the L and R panning
coefficients are provided on both the L and R sides, the values can
be set by changing a sound image position based on the number of
the pressed key.
[0034] In the present embodiment, the L panning coefficient of the
monaural tone parameters gradually decreases from 80 to 40 as the
tone goes low to high, and the R panning coefficient of the
monaural tone parameters gradually increases from 40 to 80 as the
tone goes low to high. The middle tone is set to be 70 in both the
L/R panning coefficients.
[0035] The CPU work RAM 18 is not only used as a work area of the
CPU 12, but also it stores the operation mode of the musical sound
generation channels used for musical sound generation. The CPU
program ROM 14 stores control programs and musical data for
auto-playing. In case that the musical sound signal generation
apparatus of the present invention is set to the auto-playing mode
by an operation of the panel 20, the CPU 12 may generate musical
sounds for auto-playing in the musical sound signal generation
circuit 40 in accordance with the musical data for auto-playing.
The CPU work RAM 18 is provided with batteries so that it may not
lose the stored date even if the power supply to the electronic
instrument is cut off.
[0036] The panel 20 comprises various selection switches such as
for tones, a display device having a LED or LCD, a panel scan
circuit 22 for reading the information of each switch under the
control of the CPU 12, and a panel display circuit 24 for operating
the display device. The keyboard 26 comprises, for example, a
plurality of keys, each of which having two switches, and a key
scan circuit 28 for scanning the switching state of each key under
the control of the CPU 12.
[0037] In the electronic instrument 10 of the present embodiment,
when a key on the keyboard 26 is operated, the key scan circuit 28
detects a key-on or a key-off, transmits the detected
key-on/key-off information along with the key number information to
the bus line 30. The information including the key number
transmitted to the bus line 30 are received by the CPU 12 and the
musical sound signal generation circuit 40, and also stored by the
CPU work RAM 18 under the control of CPU 12.
[0038] FIG. 2 is a block diagram showing an example of a
constitution of the musical sound signal generation circuit 40
indicated in FIG. 1
[0039] The musical sound signal generation circuit 40 can generate
individual musical sound signals of a plurality of musical sound
generation channels i.e. 32 channels in the present embodiment by
time division multiplexing processing under the control of the CPU
12. In FIG. 2, the function of only one channel is shown for easy
understanding. Each musical sound generation channel is numbered
from 1 ch to 32 ch in the present embodiment.
[0040] This musical sound signal generation circuit 40 comprises a
waveform ROM 42 for storing a plurality of sample waveform data, a
bus interface 44, a waveform reader 46 for reading sample waveform
data from the waveform ROM 42 and generating a sample waveform
based on the read sample waveform data, an envelope generator 48
for generating an envelope signal used for controlling the sound
quality, and an assignment memory 40a, which is a RAM, for
operating as a part of the musical sound signal generation circuit
40.
[0041] The bus interface 44, as a result that the various data (for
instance, the key-on/key-off information and key number
information) stored in the CPU work RAM 18 are read by the CPU 12,
receives the data transmitted from the CPU 12 via the bus line 30,
and transmits them to the waveform reader 46 and the envelope
generator 48. The waveform reader 46, in accordance with the
transmitted key number information, generates a waveform memory
read address corresponding to the pitch. The waveform memory 42 is
a memory for storing the musical waveform information corresponding
to various tones. The envelope generator 48 generates an envelope
signal to control a musical sound in accordance with the
key-on/key-off information.
[0042] The assignment memory 40a stores various key assignment
information for each musical sound generation channel.
Key-on/key-off information, key number information, a wave start
address, L and R panning coefficients, attack, decay and release
envelope data, and loudness data are the assignment information for
one channel. The assignment memory 40a can store the assignment
information for 32 channels.
[0043] The stored key-on/key-off and key number information are
transmitted from the key scan circuit 28 to the bus line 30. The
wave start address, the L and R panning coefficients and the
envelope data are obtained from the tone parameter ROM 16 based on
the tone selection switch on the panel 20. For the loudness data,
the position of the volume controller is detected by the panel scan
circuit 22, converted to a numerical value and transmitted to the
bus line 30. The assignment memory 40a stores the data related to
the key number, tone and sound volume corresponding to the sample
waveform generated by each musical sound generation channel.
[0044] In the musical signal generation circuit 40 constituted as
such, a F number corresponding to the key number from the
assignment memory 40a, the wave start address and the
key-on/key-off information are inputted to the waveform reader 46.
In the waveform reader 46, the wave start address is added to the
integer part of the F number The data after the addition specifies
the address in the waveform ROM 42. Then, the waveform reader 46
reads the sample waveform data specified by the address, and uses
the decimal part of the F number to apply an interpolation
processing to the sample waveform data.
[0045] The sample waveform data outputted from the waveform reader
46 are transmitted to a multiplier MLT1. The envelope data from the
envelope generator 48 are inputted to the multiplier MLT1, and the
sample waveform data are multiplied by the envelope data. This
envelope data are based on the attack, decay and release envelope
data supplied from the assignment memory 40 to the envelope
generator 48, and the key-on/key-off information. In addition, the
sample waveform data are multiplied by the loudness data from the
assignment memory 40a in a multiplier MLT2.
[0046] By multiplying the envelope data by the loudness data, the
musical sound signal to generate the sound corresponding to the
operated key is generated. The generated musical sound signal is
transmitted to the panning circuit 50.
[0047] The panning circuit 50 comprises an L side panning value
interpolation circuit 50L and a multiplier MLT3, and an R side
panning value interpolation circuit 50R and a multiplier MLT4. An
accumulation circuit 52 on the downstream side includes an adder
ADD3 and a latch 52L, and an adder ADD4 and a latch 52R.
[0048] The L side panning value interpolation circuit 50L and the R
side panning value interpolation circuit 50R are notified of the
presence/absence of interpolation from the CPU 12, and when there
is interpolation, transmit the panning coefficients (pan values)
obtained from the assignment memory 40a to the multipliers MLT3 and
MLT4. When the panning coefficients are transmitted to the
multipliers MLT3 and MLT4, the musical sound signal is multiplied
by the panning coefficients.
[0049] The musical sound signal is transmitted to the latches 52L,
52R via the adders ADD1, ADD2, and an accumulation processing is
performed for all the channels The accumulated musical sound signal
is analog-converted, amplified, and outputted as a musical sound to
the left and right output systems as described below.
[0050] Turning back to FIG. 1, the musical sound signal generation
circuit 40 is connected to the left output system provided with a
digital analog converter SDAC) 60L, an amplifier 62L and a speaker
(SP) 64L, and to the right output system provided with a DAC 60R,
an amplifier 62R and a speaker 64R. Each of the left and right
output systems can convert a digital signal outputted from the
accumulation circuit 52 to an analog signal, amply the signal, and
output a sound.
[0051] As shown in FIG. 3, the CPU work RAM 18 is provided with
four information storage areas, namely, basic musical sound
information storage areas 18a, key-on order management information
storage areas 18b, musical sound generation state information
storage areas 18c and chord generation information storage areas
18d.
[0052] In the basic musical sound information areas 18a, various
musical sound information to produce a sound are stored based on
various sounding conditions set by the operation of the panel 20
when a key is depressed (or when a MID1 signal is inputted). The
basic musical sound information areas 18a are provided with the
areas storing various information for a maximum of 32 channels
corresponding to the musical sound generation channels in the
musical sound signal generation circuit 40. Each area is numbered
from ch1 to ch32 (Ch#No.).
[0053] In the basic musical sound information storage areas 18a,
sound production mode information (Use#cnt) for indicating whether
the channel is in the non-sounding mode, the monaural-sounding mode
or the stereo-sounding mode, channel information (Tg#ch1, Tg#ch2)
for indicating the number of the musical sound generation channel
for generating a sample waveform in the musical sound signal
generation circuit 40, tone number information (Tone#No.) for
indicating the tone parameters read from the parameter ROM 16, key
number information (Key#No.) for indicating the pressed key, and
track information (Tr#No.) for indicating whether the sound
production is derived from a key operation or an input of a MIDI
signal are stored In the sound production mode information, a
numeral value is stored in such a way that if the channel is in the
non-silent mode, then "0" is stored; if the channel is in the
monaural-sounding mode, then "1" is stored; and if the channel is
in the stereo-sounding mode, then "2" is stored. In the channel
information, the number (1-32) of the musical sound generation
channel is stored. In case of stereo sounding, different numbers
(for instance, ch1, ch2) of the musical sound generation channel
are stored in Tg#ch1, Tg#ch2, respectively, In case of monaural
sounding, a number (for instance, ch3) of the musical sound
generation channel is stored in Tg#ch1, and 0 in Tg#ch2. In the
tone number information, in accordance with the number (for
instance, 0, 1, . . . , 100) referred to each of the plurality of
tone parameters, a numerical value (for example, in case of piano,
then 0) is stored. In the key number information, a number referred
to the key on the keyboard is stored. In the electronic instrument
10 of the present embodiment, there are 88 keys on the keyboard,
and they are numbered 1-88 in order of the position of the key from
the low to high tone.
[0054] The key-on order management information storage areas 18b
show, so to speak, the history of sound production. In those areas,
the area numbers (Ch#No.) of the basic musical sound information
storage areas 18a used for sound production are stored in order of
sound production. As shown in FIG. 3, in the key-on order
management information storage areas 18b, the area numbers (Ch#No.)
of the newest channels in order of sound production are stored in
the lower part of the areas.
[0055] In the musical sound generation state information storage
areas 18c, the information related to the sounding state of each
channel when a sound is produced in accordance with the sounding
conditions stored in the basic musical sound information storage
areas 18a are stored. The information includes the area number
(Ch#No.), envelope phase state information (Env.) when a sound is
produced in the musical sound signal generation circuit 40 based on
the area number, and the sound production information indicating
whether the area of the area number (Ch#No.) is in the silent mode
(OFF) including the non-sounding mode, or the sounding mode
(ON).
[0056] The envelope phase state information indicates 0 when the
sample waveform generated in the musical sound signal generation
circuit 40 is in the silent mode (truncate mode), 1 in case of the
attack mode, 2 in case of the decay mode, and 3 in case of the
release mode.
[0057] In the chord generation information storage areas 18d, in
accordance with the tone number information (Tone#No.) and the key
number information (Key#No.) stored in the basic musical sound
information storage areas 18a, the information indicating whether
the musical sound signal generated by each musical sound generation
channel is for chord generation or not are stored. For example,
when a musical sound generation channel is generating a sound other
than a chord, "0" is stored in the area corresponding to the
musical sound generation channel. When it is generating a chord, a
positive integer such as "1", "2", . . . "n" is stored in order of
chord generation
[0058] As seen in FIG. 3, in the areas corresponding to ch1, ch2,
values "0" are stored respectively. This means these channels are
used for generating musical sound signals to generate a sound other
than a chord. In the areas corresponding to ch3-ch8, values "4" are
stored respectively. This means each of the musical sound
generation channels has changed into the state of chord generation
fourthly since the electronic instrument 10 has started to be
played It also means that a chord consisting of three stereo sounds
are generated using six channels. In the areas corresponding to
ch28-ch32, "1" is stored respectively. This means each of the
musical sound generation channels has changed into the state of
chord generation first since the electronic instrument 10 has
started to be played. It also means a chord consisting of 1
monaural sound and 2 stereo sounds are generated using five
channels. Which channel is producing the monaural sound is known by
consulting the sound production mode information (Use#cnt) of the
basic musical sound information storage areas.
[0059] In the electronic instrument 10 constituted as above,
control processing executed by the CPU 12 is now explained with
flowcharts illustrated in the accompanying drawings of FIG.
4-6.
[0060] When power is supplied to the electronic instrument 10, the
CPU 12 executes various initialization processings (S2). Then, it
executes a panel processing (S4) for setting tones and sound
volumes corresponding to ON/OFF or the position of the mode
selection switch, tone selection switch and volume controller on
the panel 20, a key event processing (S6) for producing a sound or
silencing corresponding to a key-on/key-off, and other processings
(S8) repeatedly.
[0061] In the key event processing (S6), as shown in FIG. 5, the
CPU 12 determines whether there is a key-on based on the detection
of the key scan circuit 28 (S10), and if a key-on is present (YES
at S10), executes a sound production channel acquisition processing
(S12).
[0062] In the sound production channel acquisition processing
(S12), as shown in FIG. 6, the CPU 12 searches the CPU work RAM 18
to determine whether there is a vacant channel (S20). If a vacant
channel is present (YES at S20), the CPU 12 skips S22-S28 and
executes S30. If no vacant channel is present (NO at S20), it
searches the CPU work RAM 18 again to determine whether there are
at least a pair of stereo-sounding channels in the channels
excluding the newest 4 channels in order of sound production(S22).
If at least a pair of stereo-sounding channels exist (YES at S22),
it searches the CPU work RAM 18 to select firstly the channels from
the stereo-sounding channels excluding those generating musical
sound signals for chords. It further selects a pair of the oldest
left and right channels in order of sound production from the
selected channels. Then, it silences the R side channel of the pair
to secure a channel for a new key-on (S24). In S24, when all the
stereo-sounding channels are generating musical sound signals for
chords, a pair of the oldest channel-in order of chord production
are selected, and the R side channel of the selected pair is
silenced to be secured for the new key-on.
[0063] The panning coefficient of the remaining L side channel is
changed to be monaural sounding based on the key number of the
depressed key. When the L side channel produces a monaural sound,
loudness data of the L side channel is corrected in accordance with
the position of the volume controller on the panel 20 so that the
sound volume may be equal to volume to be outputted from both L/R
side channels as a stereo sound upon the key-on (S26).
[0064] In S22, when no stereo-sounding channel is present (that is,
all the channels are in the monaural-sounding mode) (NO at S22),
the CPU 12 searches the CPU work RAM 18 to select firstly the
channels from the monaural-sounding channels excluding those
generating musical sound signals for monaural chords. It further
selects the oldest channel in order of sound production from the
selected channels, and then silences the selected channel to secure
a channel for a new key-on (S28). In S28, when all the
monaural-sounding channels are generating musical sound signals for
chords, the oldest channel in order of chord production is selected
and silenced to be secured for the new key-on.
[0065] The CPU 12 repeats S20-S28 until the two channels necessary
for stereo sounding corresponding to a new key-on are secured. When
the two channels are finally secured, the CPU 12 updates the order
of the used area numbers of the basic musical sound information
storage areas 18a, excluding the silenced channel, in the key-on
order management areas 18b in the CPU work RAM 18 (S82). Then,
turning back to FIG. 5, the secured two channels generate musical
sound signals in stereo sounding corresponding to a new key-on, and
the generated musical sound signals are outputted via the DACs 60L,
60R, the amplifiers 62L, 62R, and the speakers 62L, 62R (S14).
[0066] In the key event processing shown in FIG. 5, when no key-on
is present (NO at S10), it is then determined whether there is a
key-off (S16). When a key-off is present (YES at S16), the channel
producing the sound is silenced (S18), and if no key-off is present
(NO at S16), S18 is skipped and the key event processing is
ended.
[0067] As explained in the above, in the electronic instrument of
the present embodiment, when there is no channel (musical sound
generation channel) to be used to generate a musical sound signal
for producing a sound corresponding to a new key-on, a pair of
channels are secured for the new key-on from the channels (28
channels) excluding the newest 4 channels in order of sound
production. This mechanism makes it possible to produce a stereo
sound corresponding to a new key-on. In addition, since the
channels to be silenced are selected from the older channels than
the newest 4 channels in sound production, it is possible to
prevent the players and the audience from having a sense of
incongruity occurred by silencing a sound of the key just
operated.
[0068] Furthermore, when there are channels generating musical
sound signals constituting a chord in the older channels than the
newest 4 channels in sound production, the channels excluding those
that are generating musical sound signals for a chord are firstly
selected as those to be silenced by some chance (that is, to be
secured as channels to generate a musical sound in stereo sounding
corresponding to a new key-on), and then, in the selected channels,
the oldest channels in sound production are further selected to be
silenced. Accordingly, when a chord is present, it is possible to
keep the state of the chord production normal. As a result, the
players and the audience are not given a sense of incongruity
occurred by silencing a sound constituting a chord.
[0069] In the selection of channels to be silenced, a pair of R and
Left side channels in stereo sounding are selected. One channel (R
side channel) out of the pair is silenced, and the other channel (L
side channel) produces a monaural sound by changing the panning
coefficient of the musical sound signal in accordance with the key
number upon the key-on. In production of the monaural sound, the
sound volume is also corrected so that it may be equal to volume
when a stereo sound is produced from both the L/R sides.
[0070] The present invention is not limited to the above
embodiment, and other modifications and variations are possible
within the scope of the present invention.
[0071] For example, in the above embodiment, S 28 is repeated till
two musical sound generation channels are secured in S30, and then
the secured musical sound generation channels are assigned to
channels for generating musical sound signals in Stereo sounding
corresponding to a new key-on. However, instead of executing S30
after S28, it is possible to newly create S31 for assigning the
musical sound generation channels silenced in S28 to those for
generating musical sound signals in monaural sounding corresponding
to a new key-on. Then, S31 can be inserted after S28, and after the
execution of S31, S32 can be executed. In addition, S14 can be
replaced to S14' which, based on the key number of the depressed
key, changes the panning coefficient of the musical sound signal
generated in the musical sound generation channel secured by S31,
and corrects the loudness data so that the loudness data based on
the position of the volume controller on the panel 20 may be equal
a volume to be outputted as a stereo sound from the L/R side
channels upon the key-on, provided that the function of the sound
production processing in S14 is principally maintained in S14'.
[0072] When two musical sound generation channels in monaural
sounding are silenced for producing a stereo sound, the audience
may have a sense of incongruity more or less for lack of the two
sounds. However, since in S28 and S31, only one Bound is silenced
for monaural sounding, it is possible to prevent the audience from
having a sense of incongruity to some extent.
[0073] Additionally, in the present embodiment, it is determined in
S22 whether the 28 channels excluding the newest 4 channels in
order of sound production are all used for stereo sounding.
However, the number of channels to be excluded can be any plural
channels such as 3 and 5 channels. Since a chord is generally
constituted of 3-4 different sounds, it is preferred that the
number of channels to be excluded is 3-4 in order to correspond
with the number of sounds constituting the chord.
* * * * *