JPS58206215A - Automatic sound volume controller - Google Patents

Abstract

PURPOSE:To avoid an excessive degree of sound volume for a high level signal without masking a low level input signal, by performing the gain control in response not only to the ambient noise level but the level of an input music signal. CONSTITUTION:When an ambient noise level detecting circuit 2 supplies the output signal of a sensor 1, the DC voltage is delivered in proportion to the level rise DELTANdB to the reference noise level NodB(A) SPL. While the level of the input signal supplied to a signal input terminal 3 is detected by an input signal level detecting circuit 8. Then the DC voltage proportional to the rise DELTASdB to the reference signal level SodBs is delivered. The output signal of the circuit 8 is multiplied by the output of the circuit 2 through an arithmetic control circuit 9 and then supplied to a gain control circuit 5 as a gain control signal A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic sound interval adjustment device, particularly for an automatic sound interval adjustment device for better listening to recombination in a place where the level of ambient noise is high. It is.

Is it easy to play when J3 is in a place where there are a lot of people around Hatake? Listening to 3, J, Udorido, J around this area 111a, 1
11 raw na 8 may be 7 swung. For example, in /J-S1 and A, if you listen to it while driving in automatic mode, the sound will be heard again when the driving noise level increases by 1.
1 Nasho sometimes gets 7 seconds and 4 times when he runs (i&! sound) and tries to C.

Binding b (which solves this problem) is a gain 1/J structure 11 corresponding to the size of the surrounding UtX as shown in Figure 1.
Purchase is proposed. This converts ambient noise into electricity No. 11 by Shinry 1, and converts this electricity (No. 8 to &!
The signal is supplied to a sound level detection circuit 2 and its level is detected 4.

The noise level detection circuit 2 detects &
! The n level is a predetermined constant # in the constant circuit 4.
, K are @pupiled and generated as gain control till f, No. 4 A.

On the other hand, an external Raku8 (i) signal is supplied to the signal input terminal 3.
The signal B is supplied to the power amplifier '6 through the gain υ'' control circuit 5, where it is amplified and then reproduced from the speaker 7. In this case, since the gain is changed by the gain control signal supplied from the constant circuit 4, when the ambient lAΔ level increases by 1, the brightness power increases accordingly. 1 above the musical sound level played back (to make listening easier.In this case, the relationship between the ambient noise level and the sound ω
As shown in the figure, as the ambient noise +1 increases, the average sound mb increases gJ1-4.

However, in the device configured as described above, the level of playback life is changed only in response to the level of the ambient noise B, and is unrelated to the musical tone signal level. Therefore,
If the level change of No. 18 is small, sufficient effect will be obtained from No. 19.
However, in a symphony, for example, where the signal level changes greatly, the low-level signal is partially masked as shown in FIG. 3(a). On the other hand, if the gain is increased so that the low-level signal C is not masked, the high-level signal e becomes audible in the part "2" and is heard noisily, as shown in Figure 3(b). I have a problem with distortion caused by power amplifiers and power amplifiers.

Therefore, the purpose of this invention is to solve the above-mentioned problem of the conventional device by creating an ambient noise L novel (1) (without -, and published corresponding to the level of the 43 GJ problem of the conventional device). f7 ゐ! 1 (J to do II, I, with a big level change, against No. 4 - (Mu effect Song's J B k1
C. To provide an automatic sound 111 adjustment device that performs adjustment <fλ.

Hereinafter, the automatic furrow stitch adjustment surface according to the present invention will be explained in detail with reference to the drawings.

FIG. 4 is a diagram showing the general configuration of the automatic sound quality adjustment device 4 according to the present invention.
I will use the first month and omit the detailed explanation.

In the same figure, 8 is an input for detecting the level of the incoming horn signal supplied to the No. 15 input terminal 3 (No. 1 is a level detection circuit, and 9 is an input to the output signal of the ambient noise level detection circuit 2). A gain control circuit for controlling the gain control circuit 5 by inputting the output signal of the level detection circuit 8, For example, J shown in Figure 5 is configured as J.
10 is supplied from the input A 5 level detection circuit 8, and the output signal 10 is supplied from the input A 5 level detection circuit 8.
d[3s) vs. 4 level” IfI! h) (Δ5d1
3) A multiplication circuit that multiplies a voltage proportional to a negative constant α, 1
1 is a filter circuit that applies a voltage corresponding to a positive constant β to the output of the control circuit 10; 12 is an ambient noise level detection port 2;
Daytime noise level (NUIIB(c)) supplied from
This is a multiplier circuit that multiplies the output voltage corresponding to the level increase line (ΔN(1B)) for the level increase line (ΔN(1B)) with the output of the adder circuit 11, and outputs a voltage proportional to ΔN(βtoαΔS).13 is a limiter circuit.

In the M position configured in this way, when the ambient U sound level detection circuit 2 receives the output signal of the sensor 1, the reference noise level NOC3 (c)
Nd81. :Proportional DC voltage is output. In this case, the reference noise level No dB (c) SPL is the lower limit of the ambient noise level that requires volume adjustment, and is generally set at 4.
It is configured to be fixed at a value between 0 and 60 dB (c) SPL or variably set to a value above 1. In addition, the ambient noise level detection circuit 2 has 111 L of ambient noise and musical sounds.
C3, which includes a circuit such as a low-pass filter,
In this way, only the ambient noise level is detected. .

h, (g+ +4 Level of input signal No. 11 supplied to input terminal 3 (5)
It is detected, and a DC voltage proportional to the 2F shift Δ5d)3 with respect to the reference im JJ level 3o C3s is output. In this case, the reference signal level 5 odBs is human noise, 1
It is desirable to set the average value at the signal level. , did, input/J (If t, > 4 is a 2-way tunnel, it is sufficient to detect the sum of the signal levels of both tunnels. One of the time constant circuit parts of the noise level detection circuit 2 and the signal level detection circuit 80 Examples are shown in Figs. The lC time constant is determined by the resistor R3 and the resistor C3, respectively;
'S a /I-O, D is a diode for backflow prevention,
AIG amplifier (・There is. Jj in signal level detection circuit 8
l) Time constant τ for detection time constant IJ level 1 shift
The time constant xr(s) for the b level decrease is calculated from γ(S), or the ambient noise level detection circuit 2
It is desirable to set the detection time constant τn(s)J=smaller. Towards ease (When No. 11 is at a small level, the gain is controlled to be large, so if the time constant τγ is not kept small, if there is a sudden increase in level, it will be reproduced as an extremely crowded level.) However, on the contrary, the gain is controlled so that it becomes small when the level is large, so unless the time constant τ is set to a certain degree, the gain will be extremely small if there is a sudden drop in the level. There are J3 that are reproduced as levels, and the time constant τγ is changed to the time constant τ ``J
, it is possible to obtain a natural reproduced sound by making it smaller. Furthermore, the level change of the musical tone level (ij) is generally larger than the noise level change, and the time constant τ
γ and τf are set smaller than the time constant τ11 so as to be able to follow sudden changes.

In this way, the output signal of the input level detection circuit 8 is multiplied by a negative coefficient α in the @shaft circuit 10. A constant that determines the rate of increase in the degree of compression at the circle level,
Generally, the user can arbitrarily set the value to -0,04<α≦0. Then, to this ID, s* circuit 10, an electric current n corresponding to the positive coefficient β is added to the adder circuit 11. In this case, in the l-8 level field around βLL, Comparing standard level formula] J i= g
11Q is a constant that determines the rate of increase in 1g of paper (in general, O≦β and 1). 12 is the constant of the ambient noise level detection circuit 2. The output of the output Q circuit 11 is the east Q circuit where the output is the east p4.
The output voltage In is proportional to ΔN (β+UΔS).

J3, east 9 circuit 12, using a 2-quadrant east sieve, positive polarity input 9i; By connecting the output, the ambient noise level can be reduced to 1uLILu.
When the sound level is below C, when ΔN≦0, the output is set to O and the volume is not adjusted (C).
Wear. This J, sea bream; J2 caught bell circuit 12
Gain j+'J flilJtall 1. ,
No. △ is supplied. In this case, profit j'; J III
Since the J circuit 5 is a variable gain 1η circuit constituted by a voltage series amplifier or the like whose gain can be controlled logarithmically, By matching the output voltage sensitivity, the gain ΔGdβ for the 4t human power supplied from the signal input terminal 3 and the moon satisfies the formula ΔG=ΔN(β′αΔS>...(1)) J. Sea urchins can be controlled.

Figure 6 shows the volume adjustment effect on the recording device. In the same figure, J3 is shown, and the maximum value of the input No. 18 level is SO+Δ5IllaxdB, and the minimum value is 3o4ΔS10.
dB (ΔSmax > 0. H3min <Q), and the vertical axis shows the sum of the input signal level and gain in small dB units so as to correspond to the volume. Further, the horizontal axis indicates the ambient noise level in units of d13. Then, when the ambient noise n level is M quasi-noise and is below Nod13(c), 51)L (indicated by a in the figure), the 8111 adjustment is not performed f1.
△G=0 What's going on? Next, the ambient noise t) level is earth fI
I! The volume is then adjusted according to equation (1) above. Here, upper @ Ki ΔN d [3 (already accepted in the diagram) is 1
Yo, average (3rd level (S.

The gain ΔG1 for d13s) is based on (1) above) [, ΔG! = △Nβ. Similarly, increase the 46 gain to the k large i January level (So'+・ΔS ll1dX ) *minimum No. 15 level (80+ΔSn+in),
If we take Δ02.60m (18), we get 8Gz□-ΔN (βIU△3max) ΔG30.△N (β1°αΔ31++). Here (
゛, ΔN≧0. β and O1α≦0゜Δ3a+ax>O, Δ
3 sin −=:, O is/, − to ΔG! ≦△
G1≦ΔG, yell. In other words, the smaller the No. 13 level, the lower the profit (η is the human power, and the signal level is adjusted so that the signal level and the publication are smaller. Therefore, depending on the surrounding noise level, the lower level of human power is 1. No.A is not 7song and the high level signal becomes excessively loud.
After that, appropriate adjustments are made. In addition, if the ambient noise level is sufficiently low (ΔN≦0), ΔG
=-=O, so it is automatically returned to the state in which the 8-tone adjustment is not performed.

Next, this J: Criteria for when using eel soukan @
I will now discuss the relationship between the effects of mouth settings.

Here, M single note noise and 1 refer to the overall size of the pitch depending on individual preference, and when the ambient noise is sufficiently small, ΔN≦O)
This corresponds to the overall size of the trading company. In the symbol level detection circuit 8', the MtSL value for level detection is normally fixed. Therefore, although this reference self-setting is performed before the detection of the No. 16 level, the adjustment effect will be different depending on whether it is performed afterwards. In Fig. 7, when the control constants α and β are JimJ-, the reference sound layer is set by the volume of the tape deck, duplex, etc. before being input to this device (the fourth
Figure 7(b) shows the adjustment effect when setting the level of the signal input manually to terminal 3 at J3, and Figure 7(b) shows the adjustment effect when setting the standard 6 quantity after detecting the signal level within the device or after the device. (Figure 4 shows the adjustment effect when the level is set at the input or output end of No. 13 of iJ3 and gain fbq Oguchiji 5). The larger the control constant β becomes (the smaller it becomes)
The distance between the reference tones is large (it is thought that there are very few, so the 7th of the former is more important than the rear right).
"4" shown in (a) is J due to the adjustment effect, and then it hovers at 0 in the Ω constant range of i11 control constant σ.

If J is in this mounting d, then the surrounding u R level 1 shi I, I made it into a clam of U〕°(Shin >Lebel's J, i Jii
i l sadness increases, but l tx l is lonely h pino △
If N is large, see Figure 8! lJ, a reversal phenomenon occurs in the relationship between volume levels. Two different signal levels △8
1. J profit 1η for Δs2 (where ΔS1>ΔSs)
1) According to equation (1) in b. I is Δ
S1 ΔG1≧Δ3. +ΔG.

Accordingly, the range of α from these formulas is −(1,z′Δ
N) ≦a medium and <C, the setting range on the side where ΔN is large becomes smaller.

In this device, the maximum of ΔN is 1 (t is 25 (d3), and 0
．． 04≦α≦0.

Next, we will discuss how to prevent the phenomenon of decrease in d profit (q) for surrounding & 18th level -L nails.As is clear from the above equation (1), β is small and 1α1 and ΔS are both large. In such cases, the gain ΔG may become negative as shown in Fig. 9. To prevent this phenomenon, the present device e uses a limiter circuit 13 having diode characteristics to prevent the gain ΔG from becoming ΔGoo. It is desirable that the limiter circuit 13 be provided at the input stage of the frame circuit 12.In other words, the evaporation circuit 12 should output an output only when both forces are positive. It is also possible to use a one-inlay sieve configuration.

Figure 10 shows automatic volume adjustment according to this invention! Another embodiment of li times is shown, in which the same parts as in FIG. 5 are denoted by the same symbols. In the same figure, 10' is a multiplication circuit that calculates a constant β to the output J of the noise level detection circuit 2, and 14 is an addition circuit with a switch connected to the output side of the multiplication and sieving circuit 10. 11 adds the output of the multiplication circuit 10' and the output of the multiplication circuit 10 supplied via the switch 14, and supplies the output to the gain control circuit 5.

In this circuit configured as above, the degree of compression of the signal is constant regardless of the ambient noise level.
,:H with a small level change (for Ij), open the switching swing 14,
For the number, the adjustment effect shown in Fig. 11 can be obtained by closing the swing f14 for one cut. In this case, J31]rua,l+omiki(yo,Δ
G=βΔN (:), Iyzo 14,4711. +1)Δ
G・βΔN + txΔS (when swing is 14A) However, β≧0, −1≦U≦or.

FIG. 12 is a four-circuit diagram showing another embodiment of the present invention, and the same parts as those in FIG. 10 are shown using the same numbers H. In the same figure, 13 indicates the output of the adder circuit 11 (1, which corresponds to the negative constant ΔST, and adds the voltage and the output of the bell circuit 10'. 15 indicates the output of the adder circuit 11 as a signal. It is a reduction circuit 1h from the output of the level detection circuit 8. The signal is supplied to the gain control circuit 5 via -(.

In a circuit configured in this way, the diC is
Due to the increase in the number of fields, mass 4-ng was received]ノ/, J: IJ,
The signal level is gradually raised from a low signal level. In this case, the control equation is γ=Δ
S-βΔN-ΔS], ■ When γ is O, ΔG″・α・γ ■ When γ≧O, ΔG=0, and the control characteristic number shown in FIG. 13 is obtained.

However, [Haβ≧0, -1≦α, <O'c exists, ΔS[ is Δ
We carry out the calculation of the gain of N=O (1. of the j'g level, which is fixed or variable).

As explained above, according to the invention A, gain control is automatically performed not only for the input (No. 4 level) but also for the input (No. 4 level). This is an excellent feature that allows you to effectively adjust the sound FFI without masking at low levels or causing people to listen to J3 at high levels. It is effective.

[Brief explanation of the drawing]

! Figure '11 is a circuit diagram showing the conventional automatic 8-temperature adjustment device 4, Figures 2 and 3 (a), (1, 1) are characteristic diagrams of Figure 1,
FIG. 4 is a diagram showing the general configuration of the present invention; FIG. 5 is a circuit diagram of an embodiment of the automatic sound ω adjustment device according to the present invention; FIGS. 6 and 7 (ia)'; )), Figures 8 and 9 are the characteristic diagrams of Figures 4 and 5, Figure 10 is the characteristic diagram of Figure 1, and Figure 11 is the characteristic diagram of Figure 10. 1
Figure 2 is a circuit diagram of other embodiments, Figure 13 is IJ No. 1.
2 is a characteristic diagram, FIG. 14 is a circuit diagram showing an embodiment of the noise level detection circuit, and FIG. 15 is a circuit diagram of an embodiment of the f5 level detection circuit. 1...sen 1 no, 2...noise level detection circuit, 5
... paddy 1iJ control circuit, 6... power amplifier, 1.
...Speaker, 8...FIJ bow level detection circuit, 9.
...Ruri formation circuit, 10゜10'... @ formation circuit, 1
1... Addition circuit, 12... Tojin circuit, 13... Limiter circuit, 14... Switch, 15... Reduction circuit. Figure 5 9 Figure 6 Figure 7 ((1) (b) Figure 8
Figure 9 110 r2'! 111th”:'1
ΔG: β, ΔN+(/ΔS Figure 12 Figure 13 No. Deflection 111j+!IL
NL Figure 14? FIG.
4. '[1, ji 11 hands Showa 5 'νl 4:11 〆1餉 90th/10th March Higashishinto 1, 1 Kuro 1 each Meguro/Monday 114 Akira' (! + (11
)Nobun I A Ninono 4ri,'' (Meeting: l-Kumibetsu-gumi and J Meri (attached sheet) 2, Special 6'l 'ui! There's a smell in a certain place'? Rakuhata (6
Amplify the C (within Ai-S, -, Jj I(,g B (1) +9 + Increment ΔN from the constant 4ty level and the increment of the predetermined reference level hl '3 of Naai 4g By detecting ΔS4 and including both components of the increment ΔN1ΔS: >3, the amplification gain (q
The change Δ(1) is controlled, and the increment ΔN4r+1+ !
Detecting the detection time constant ・Detecting the increment ΔS 4 Detecting 113 constants L, /ζ 4 Automatic sound i
Key 1! ! Device. (2) Detection time constant 11 for detecting the increment ΔS, ljB when the Rakuhata signal increases/decreases 4
Automatic 8ki tone U device 1 characterized by being user-friendly. (3) The change in gain ΔG is calculated by setting U to a negative coefficient. When β is a coefficient of 1, it corresponds to the value of (β1αΔS) and the increment ΔN. Automatic 1 described in Section 2
゜1 key V unit ♂♂1: Medium Absolute 1# LL of the coefficient α, the 1(+7 1,
The maximum of 7ΔN (d+ inverse #Il%l・(1!I-Claims: (1.04 Ls1((
Characterized by b! ．． : 'J 'e'1M"61
uH calculation g) N 31st rr, Jl t: c. + Automatic 'S e! on the 4th beat! l adjustment i4 min. 1 mouth) The coefficient β! 1, (eyes 1, 11 so 1・(a L)
-,, /: 'a1: r fine and characteristic ♂ 1 item range 3rd III% to 4th Ej Iff's range' j
Automatic γ on iL! Ik! Adjust! ,'M'/. 17゛ The coefficient (χ. β of 5 #r, '. Shime 1
〈Either Tora - /, Lo use f'+ /J' {[ @
G, 2 settings I 1J
! Ia'l crystal book range No. 6 JJ"i
Which of these is C, automatic f4 victory 1 maintenance defense described in ゛. idi The musical note I,, of the bow! The previous stage of detecting the wear △S 《32〉(, the music 1'', I Hr.S: J, J t
p sono. The automatic adjustment device according to any of the preceding paragraphs 1 to 7;

Claims (2)

[Claims] (1) At a place where there is ambient & IB, Rakuhata I amplifies No. 1 and repeats it again. At 1 d, detect the ambient noise level of 1. Surrounding &! B level detection circuit and input (installation of No. 4jj level detection circuit that detects the level of No. i3)
, the output PI is controlled by the output power of this rain detection circuit1! J
An automatic abutment adjustment device characterized by: (2) The automatic 8-volume adjustment device according to Section 11, Section 1, characterized in that the gain control coefficient based on the input signal level varies depending on the ambient noise level.