Audio system and method for adjusting audio signal in real time according to environmental noise

Abstract

The invention discloses an audio system and method for adjusting an audio signal in real time according to environmental noise. The method comprises the following steps: receiving and preliminarily processing an externally input audio signal through an audio input module; receiving an audio signal sent by the audio input module through an amplitude limiting circuit module and carrying out amplitude limiting processing; detecting a noise value of a place where the sound reinforcement module is located through a noise detection module; and receiving the audio signal processed by the amplitude limiting circuit module through a gain adjustment module, and performing gain adjustment on the audio signal based on a comparison result of the detected noise value and a preset reference noise value. According to the invention, the noise detection module detects the noise value of the place where the sound amplification module is located, and the gain adjustment module performs gain adjustment on the audio signal based on the comparison result of the detected noise value and the preset reference noise value, so that the output volume of the sound amplification module is automatically adjusted along with the environmental noise in the use process of the audio system. And the user experience is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of audio information processing, and in particular to an audio system and method for adjusting an audio signal in real time according to environmental noise. Background Art

[0002] In existing traditional audio devices, after audio input, the audio is output by the speaker. The volume of the audio signal output by the speaker changes with the strength of the audio input signal. Especially under the premise that there are multiple forms of audio input, different audio input signal strengths often cause the volume of the audio signal output by the speaker to change, resulting in unstable volume of the audio signal output by the speaker. There is a problem that the sound emitted by the speaker fluctuates, which is not conducive to user experience.

[0003] Therefore, it is urgent to propose an audio system that adjusts the audio signal in real time according to the ambient noise to solve the problem raised. Summary of the invention

[0004] Based on this, it is necessary to provide an audio system and method for adjusting audio signals in real time according to ambient noise in order to address the deficiencies in the prior art. During the use of the audio system, the volume of the speaker output is automatically adjusted according to the ambient noise, thereby effectively improving the user experience.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] In a first aspect, an audio system for adjusting audio input in real time according to environmental noise is provided, which includes an audio input module, a limiting circuit module, a gain adjustment module and a noise detection module, wherein the audio input module is used to perform preliminary processing on an audio signal, the limiting circuit module is electrically connected to the audio input module and is used to perform appropriate amplitude limitation on the audio signal processed by the audio input module, the noise detection module is connected to the gain adjustment module, the gain adjustment module is connected to the limiting circuit module, the noise detection module is used to detect an external environmental noise value, the gain adjustment module is used to perform gain adjustment on the audio signal processed by the limiting circuit module based on a comparison result between the detected noise value and a preset reference noise value, and the gain adjustment module is used to connect to a sound reinforcement module.

[0007] In one embodiment, it is characterized in that the audio input module is also used to identify the input mode of external audio.

[0008] In one embodiment, the audio input interface of the audio input module is a common interface for line input and microphone input.

[0009] In one embodiment, it is characterized in that the audio input module includes operational amplifiers U1B, U1A, resistors R5, R8, R3, R6, R9, R10, R12, R7, R11, R4, capacitors C5, C10, C3, C12, C7, C6, C11, C4, C8, and an electronic gain selection switch U2, the positive input end of the operational amplifier U1B is respectively connected to one end of the resistor R3, one end of the capacitor C6, one end of the resistor R6, and one end of the capacitor C7, the negative input end of the operational amplifier U1B is respectively connected to one end of the resistor R9, one end of the resistor R10, one end of the resistor R12 and the other end of the capacitor C6, one end of the capacitor C11, the other end of the capacitor C11, the resistor R10, and the resistor R11. 2 are respectively connected to pin 1, pin 2, and pin 3 of the electronic gain selection switch U2, the output end of the operational amplifier U1B is respectively connected to the other end of the capacitor C11 and one end of the capacitor C4, and the other end of the capacitor C4 is connected to one end of the resistor R7; the other end of the resistor R3 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is respectively connected to one end of the resistor R5, one end of the capacitor C5 and the audio input interface terminal IN1_P; the other end of the resistor R9 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is respectively connected to one end of the resistor R8, one end of the capacitor C10 and the audio input interface terminal IN1_N, and the other ends of the resistors R6, R5, R8, capacitors C7, C5 and C10 are respectively grounded to GND;

[0010] The positive input terminal of the operational amplifier U1A is grounded, the negative input terminal of the operational amplifier U1A is respectively connected to the other end of the resistor R7, one end of the capacitor C8, and one end of the resistor R11, the output terminal of the operational amplifier U1A is respectively connected to one end of the resistor R4, the other end of the capacitor C8, and the other end of the resistor R11, and the other end of the resistor R4 corresponds to the output terminal LIN / MIC_ADUIO of the audio input module.

[0011] In one embodiment, it is characterized in that the limiting circuit module is a limiting chip IC1, the output end LIN / MIC_ADUIO of the audio input module is coupled into the input pin 3 of the limiting chip IC1 through capacitor C14, the output pin 2 of the limiting chip IC1 is connected to the gain adjustment module through capacitor C13, the pin 6 of the limiting chip IC1 is connected to resistors R13 and R14 and then grounded, the pin 4 of the limiting chip IC1 is connected to capacitor C15 and then grounded, and the pin 5 of the limiting chip IC1 is connected to capacitor C16 and then grounded.

[0012] In a second aspect, a method for adjusting audio input in real time according to environmental noise is provided, characterized in that it includes:

[0013] Step S110, receiving and preliminarily processing an external input audio signal through an audio input module;

[0014] Step S120, receiving the audio signal sent by the audio input module through the limiting circuit module and performing limiting processing;

[0015] Step S130, detecting the noise value of the place where the sound reinforcement module is located by the noise detection module;

[0016] Step S140: receiving the audio signal processed by the limiting circuit module through the gain adjustment module, and performing gain adjustment on the audio signal based on a comparison result between the detected noise value and a preset reference noise value.

[0017] In one embodiment, it is characterized in that it also includes

[0018] Step S110 - 1 , identifying the input mode of external audio through the audio input module; wherein the input mode includes a common line input mode and a microphone input mode.

[0019] In one embodiment, it is characterized in that the audio input module includes operational amplifiers U1B, U1A, resistors R5, R8, R3, R6, R9, R10, R12, R7, R11, R4, capacitors C5, C10, C3, C12, C7, C6, C11, C4, C8, and an electronic gain selection switch U2, the positive input end of the operational amplifier U1B is respectively connected to one end of the resistor R3, one end of the capacitor C6, one end of the resistor R6, and one end of the capacitor C7, the negative input end of the operational amplifier U1B is respectively connected to one end of the resistor R9, one end of the resistor R10, one end of the resistor R12 and the other end of the capacitor C6, one end of the capacitor C11, the other end of the capacitor C11, the resistor R10, and the resistor R11. 2 are respectively connected to pin 1, pin 2, and pin 3 of the electronic gain selection switch U2, the output end of the operational amplifier U1B is respectively connected to the other end of the capacitor C11 and one end of the capacitor C4, and the other end of the capacitor C4 is connected to one end of the resistor R7; the other end of the resistor R3 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is respectively connected to one end of the resistor R5, one end of the capacitor C5 and the audio input interface terminal IN1_P; the other end of the resistor R9 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is respectively connected to one end of the resistor R8, one end of the capacitor C10 and the audio input interface terminal IN1_N, and the other ends of the resistors R6, R5, R8, capacitors C7, C5 and C10 are respectively grounded to GND;

[0020] The positive input terminal of the operational amplifier U1A is grounded, the negative input terminal of the operational amplifier U1A is respectively connected to the other end of the resistor R7, one end of the capacitor C8, and one end of the resistor R11, the output terminal of the operational amplifier U1A is respectively connected to one end of the resistor R4, the other end of the capacitor C8, and the other end of the resistor R11, and the other end of the resistor R4 corresponds to the output terminal LIN / MIC_ADUIO of the audio input module.

[0021] In one embodiment, it is characterized in that the method of step S130 specifically operates as follows:

[0022] Preset three noise detection frequencies;

[0023] Collect environmental noise data and pre-process the collected noise data;

[0024] Analyze the noise data and obtain the noise level at each frequency point by calculating the noise power spectrum density;

[0025] The noise levels of the three noise detection frequency points are integrated, and the noise value of the current environment is obtained by taking the average or median.

[0026] In one embodiment, it is characterized in that the method of step S140 specifically operates as follows:

[0027] Obtaining a gain adjustment coefficient (CN-RN) / GR based on a comparison result between the detected noise value and a preset reference noise value;

[0028] By performing gain adjustment on the audio signal AF processed by the limiting circuit module through the gain adjustment coefficient, the audio signal AL=[1+(CN-RN) / GR]*AF sent to the sound reinforcement module can be obtained, wherein CN is the noise value of the place where the sound reinforcement module is located detected by the noise detection module, RN is the preset reference noise value, and GR is the preset gain ratio.

[0029] In summary, the audio system and method of the present invention for adjusting the audio signal in real time according to the environmental noise can effectively retain the structural information of the speech signal by calculating through channels based on convolutional neural networks and recurrent neural networks. At the same time, the channel feature normalization method can make the model training more stable and reduce the impact of the output speech amplitude. This module is an important part of the model parameter quantity. Therefore, the purpose of reducing the overall parameter quantity of the model is achieved through parameter sharing, and the attention mechanism is used for the encoding and decoding information to make the model pay more attention to the important information part more effectively. In addition, the deep filtering method is used to link the previous and next speech frame information, thereby further improving the output speech signal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a structural block diagram of an audio system for adjusting audio input in real time according to ambient noise provided by an embodiment of the present invention;

[0031] Figure 2 is a circuit schematic diagram of an audio input module provided by an embodiment of the present invention;

[0032] Figure 3 is a circuit schematic diagram of a limiting circuit module provided in an embodiment of the present invention;

[0033] Figure 4 is a curve diagram showing the relationship between the reference noise electrical value and the current noise value provided by an embodiment of the present invention;

[0034] Figure 5 is a flowchart of a first method for adjusting audio input in real time according to environmental noise provided by an embodiment of the present invention;

[0035] Figure 6 It is a flowchart of a second method for adjusting audio input in real time according to environmental noise provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", "third", "fourth", etc. in the specification and claims of the present invention are used to distinguish different objects rather than to describe a specific order. The terms "including" and "having" in the embodiments of the present invention and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] Figure 1 A schematic diagram of an audio system for adjusting an audio signal in real time according to ambient noise provided by the present invention is shown. Figure 1The audio system for adjusting the audio signal in real time according to the ambient noise includes an audio input module 100, a limiting circuit module 200, a gain adjustment module 300 and a noise detection module 400. The audio input module 100 is used to perform preliminary processing on the audio signal. Specifically, the audio input module 100 is used to perform preliminary amplification processing on the audio signal so as to provide a suitable signal output for the audio system; the limiting circuit module 200 is electrically connected to the audio input module 100, and is used to perform a suitable amplitude limitation on the audio signal processed by the audio input module 100, so as to ensure that the output audio signal is not distorted, thereby ensuring the normal operation of the audio system and improving the experience of the audio device; the noise detection module 400 is connected to the gain adjustment module 300, the gain adjustment module 300 is connected to the limiting circuit module 200, and the gain adjustment module 300 is connected to the gain adjustment module 300. It is used to connect the sound reinforcement module 500, and the sound reinforcement module 500 is used to convert the audio signal passed through the gain adjustment module 300 into sound and then emit it. The noise detection module 400 is used to detect the external environmental noise value. Specifically, the noise detection module 400 is used to detect the noise value of the place where the sound reinforcement module 500 is located, so as to avoid the noise value of the place where the sound reinforcement module 500 is located being higher than the sound emitted by the sound reinforcement module 500, thereby affecting the effect of the user hearing the sound emitted by the sound reinforcement module 500; the gain adjustment module 300 is used to perform gain adjustment on the audio signal processed by the limiting circuit module 200 based on the comparison result between the detected noise value and the preset reference noise value, so that during the use of the audio system, the output volume of the sound reinforcement module 500 is automatically adjusted according to the environmental noise, thereby effectively improving the user experience; in this embodiment, the sound reinforcement module 500 is a speaker structure.

[0039] In one embodiment, the audio input module 100 is also used to identify the input mode of the external audio and send the audio signal to the limiting circuit module 200; specifically, the input mode includes a common line input mode and a microphone input mode.

[0040] Specifically, the audio input interface of the audio input module 100 is a common interface for ordinary line input and microphone input. The audio input module 100 provides a suitable signal output for the audio system, so that dynamic gain selection can be achieved regardless of the external audio source of any input method sharing one interface, thereby increasing the stability of the audio system, and realizing preliminary processing of the audio signal by using hardware, which also reduces the redundancy and complexity of the software.

[0041] For further information, see Figure 2The audio input module 100 includes operational amplifiers U1B, U1A, resistors R5, R8, R3, R6, R9, R10, R12, R7, R11, R4, capacitors C5, C10, C3, C12, C7, C6, C11, C4, C8, and an electronic gain selection switch U2. The positive input terminal of the operational amplifier U1B is respectively connected to one end of the resistor R3, one end of the capacitor C6, one end of the resistor R6, and one end of the capacitor C7. The negative input terminal of the operational amplifier U1B is respectively connected to one end of the resistor R9, one end of the resistor R10, one end of the resistor R12 and the other end of the capacitor C6 and one end of the capacitor C11. The other end of the capacitor C11, the resistor R10, and the resistor R12 are respectively connected to the electronic gain selection switch U2. Pin 1, pin 2, and pin 3 of the sub-gain selection switch U2 and the output end of the operational amplifier U1B are respectively connected to the other end of the capacitor C11 and one end of the capacitor C4, and the other end of the capacitor C4 is connected to one end of the resistor R7; the other end of the resistor R3 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is respectively connected to one end of the resistor R5, one end of the capacitor C5 and the audio input interface terminal IN1_P; the other end of the resistor R9 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is respectively connected to one end of the resistor R8, one end of the capacitor C10 and the audio input interface terminal IN1_N, and the other ends of the resistor R6, the other end of R5, the other end of R8, the other end of the capacitor C7, the other end of C5, and the other end of C10 are respectively grounded GND.

[0042] The positive input terminal of the operational amplifier U1A is grounded, and the negative input terminal of the operational amplifier U1A is respectively connected to the other end of the resistor R7, one end of the capacitor C8, and one end of the resistor R11. The output terminal of the operational amplifier U1A is respectively connected to one end of the resistor R4, the other end of the capacitor C8, and the other end of the resistor R11. The other end of the resistor R4 corresponds to the output terminal LIN / MIC_ADUIO of the audio input module 100, that is, the other end of the resistor R4 is connected to the limiting circuit module 200.

[0043] The above-mentioned audio input module 100 is to provide different gain selections for different external audio source inputs. The main implementation principle is: when a line input audio source is used, the audio signal is coupled through the audio input interface IN1_P, IN1_N, GND through capacitors C3 and C12, and then connected to resistors R3 and R9 and input to the positive and negative input terminals of the operational amplifier U1B respectively. At the same time, the electronic gain selection switch U2 will select the LIN_AP corresponding to pin 1 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2. The resistor R12 is used as the gain feedback resistor for the line input audio source, so that after the first stage amplification, the output of the operational amplifier U1B is coupled with the capacitor C4 and output to the operational amplifier U1A for the second stage operational amplification, and finally sent to the next stage limiting circuit module 200 through the output terminal LIN / MIC_ADUIO of the audio input module 100.

[0044] When a microphone is used to input a sound source, the audio signal is coupled through the audio input interfaces IN1_P, IN1_N, and GND through capacitors C3 and C12, and then connected to resistors R3 and R9 and input to the positive and negative input terminals of the operational amplifier U1B respectively. At the same time, the electronic gain selection switch U2 will select the MIC_AP corresponding to pin 2 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2. The resistor R10 is used as a gain feedback resistor when the microphone is input to the sound source. After the first stage of amplification, the audio signal is coupled through the output of the operational amplifier U1B and the capacitor C4 and output to the operational amplifier U1A for the second stage of operational amplification, and finally sent to the next stage of limiting circuit module 200 through the output terminal LIN / MIC_ADUIO of the audio input module 100.

[0045] Among them, the model of the electronic gain selection switch U2 is HCF4052. The level configuration of pins 9 and 10 in the electronic gain selection switch U2 is used to control the LIN_AP corresponding to pin 1 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2, or the MIC_AP corresponding to pin 2 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2.

[0046] In one embodiment, the limiting circuit module 200 uses a limiting chip IC1 with model number NJM2762RB2. When the previous-level audio signal suddenly increases to a certain signal amplitude value, the limiting circuit module 200 can perform appropriate amplitude limitation on it, thereby ensuring that the output audio signal is not distorted, thereby ensuring the normal operation of the audio system and improving the experience of the device.

[0047] Specifically, see Figure 3The output terminal LIN / MIC_ADUIO of the audio input module 100 is coupled to the input pin 3 of the limiter chip IC1 through the capacitor C14, the output pin 2 of the limiter chip IC1 is connected to the gain adjustment module 300 through the capacitor C13, the pin 6 of the limiter chip IC1 is connected to the resistors R13 and R14 and then to the ground, the pin 4 of the limiter chip IC1 is connected to the capacitor C15 and then to the ground, and the pin 5 of the limiter chip IC1 is connected to the capacitor C16 and then to the ground; the pin 6 of the limiter chip IC1 ensures the audio through the appropriately configured parameters of R13 and R14. The signal amplitude value, together with the appropriately configured capacitor C15 parameters, ensures that the limiting signal has a suitable suppression curve, so that a relatively large amplitude audio signal is not obviously abrupt after being sent to the limiting circuit module 200, thereby ensuring high-quality analog audio signals to subsequent modules such as the gain adjustment module 300 and the sound reinforcement module 500, thereby ensuring the experience and stability of the equipment; wherein, the processing process of the audio signal by the limiting chip IC1 of NJM2762RB2 itself does not involve the inventive point of the present invention, it is a known technology and need not be elaborated here.

[0048] In one embodiment, the specific operation of the noise detection module 400 detecting the noise value of the place where the sound reinforcement module 500 is located is as follows: three noise detection frequency points are preset to be 230 Hz, 600 Hz, and 1100 Hz, respectively, and the sampling time of the noise detection module 400 is 30S. First, the collected noise data is preprocessed, such as filtering and denoising, signal amplification, etc., to improve the quality and availability of the data, analyze the noise data, calculate the noise level of each frequency point (calculate parameters such as noise power spectral density (PSD) or noise coefficient), integrate the noise values ​​of the three frequency points together, and synthesize these values ​​by taking the average, median or other statistical methods to obtain a noise value representing the current environmental noise level.

[0049] In one embodiment, the on-site environmental noise cannot remain unchanged, and the environmental noise value needs to be detected in real time, so as to compare the detected noise value with the set reference noise value, and obtain the noise difference by subtracting the two, so as to determine whether the audio signal needs to be amplified or reduced; when the detected noise value is subtracted from the set reference noise value to be a negative number, it means that the on-site environmental noise value is too small, and the audio signal gain coefficient can be synchronously adjusted down as needed, the external sound of the speaker is reduced, and the user can still clearly hear the broadcast sound emitted by the speaker; when the detected noise value is subtracted from the set reference noise value to be a negative number, it means that the on-site environmental noise value is too large, and the audio signal gain coefficient can be synchronously adjusted up as needed, the external sound of the speaker is increased, and the user can still clearly hear the broadcast sound emitted by the speaker even in a noisy environment, so that during the use of the audio system, the output volume of the sound reinforcement module 500 is automatically adjusted according to the environmental noise, which is more intelligent and humane, effectively improving the user experience, thereby increasing the stability of the audio system and increasing the competitiveness of the product.

[0050] Specifically, see Figure 4 , based on the comparison result between the detected noise value and the preset reference noise value, the gain adjustment coefficient (CN-RN) / GR is obtained, and the audio signal AF processed by the limiting circuit module 200 is gain-adjusted by the gain adjustment coefficient, so that the audio signal AL=[1+(CN-RN) / GR]*AF sent to the sound reinforcement module 500 can be obtained, wherein CN is the noise value used by the noise detection module 400 to detect the location where the sound reinforcement module 500 is located, RN is the preset reference noise value, GR (GainRatio) is the preset gain ratio, which can be selected as 6:3, 5:3, 4:3, 3:3, 3:4, 3:5, 3:6, Min.Gain≤CN≤Max.Gain, Min.Gain≤RN≤Max.Gain, Min.Gain=-18~-3DB, Max.Gain=-15~-0DB.

[0051] See also Figure 5According to the above-mentioned audio system of the present invention that adjusts the audio signal in real time according to the environmental noise, the present invention provides a method for adjusting the audio signal in real time according to the environmental noise. The audio input module, the limiting circuit module, the gain adjustment module and the noise detection module involved in the method can be the same as the technical features described in the above-mentioned embodiment of the audio system that adjusts the audio signal in real time according to the environmental noise, and can produce the same technical effects. The method of the present invention that adjusts the audio signal in real time according to the environmental noise detects the noise value of the place where the sound reinforcement module is located through the noise detection module, and the gain adjustment module performs gain adjustment on the audio signal based on the comparison result between the detected noise value and the preset reference noise value. Then, during the use of the audio system, the output volume of the sound reinforcement module is automatically adjusted with the environmental noise, effectively improving the user experience.

[0052] Figure 5 is a flowchart of a method for adjusting an audio signal in real time according to environmental noise provided by an embodiment of the present invention. Figure 5 The method for adjusting the audio signal in real time according to the ambient noise includes steps S110 to S140, which are specifically as follows:

[0053] Step S110, receiving and preliminarily processing an external input audio signal through an audio input module;

[0054] Step S120, receiving the audio signal sent by the audio input module through the limiting circuit module and performing limiting processing;

[0055] Step S130, detecting the noise value of the place where the sound reinforcement module is located by the noise detection module;

[0056] Step S140: receiving the audio signal processed by the limiting circuit module through the gain adjustment module, and performing gain adjustment on the audio signal based on a comparison result between the detected noise value and a preset reference noise value.

[0057] In one embodiment, see Figure 6 , before step S110, further comprising

[0058] Step S110-1, identifying the input method of external audio through the audio input module; wherein the input methods include ordinary line input method and microphone input method, the audio input interface of the audio input module is a common interface for ordinary line input and microphone input, and the audio input module provides a suitable signal output for the audio system, so that no matter what input method the external audio source shares one interface, dynamic gain selection can be achieved, thereby increasing the stability of the audio system, and using hardware to achieve preliminary processing of the audio signal, which also reduces the redundancy and complexity of the software.

[0059] Specifically, see Figure 2 The audio input module includes operational amplifiers U1B, U1A, resistors R5, R8, R3, R6, R9, R10, R12, R7, R11, R4, capacitors C5, C10, C3, C12, C7, C6, C11, C4, C8, and an electronic gain selection switch U2. The positive input terminal of the operational amplifier U1B is respectively connected to one end of the resistor R3, one end of the capacitor C6, one end of the resistor R6, and one end of the capacitor C7. The negative input terminal of the operational amplifier U1B is respectively connected to one end of the resistor R9, one end of the resistor R10, one end of the resistor R12 and the other end of the capacitor C6 and one end of the capacitor C11. The other end of the capacitor C11, the resistor R10, and the resistor R12 are respectively connected to the electronic gain selection switch U2. Pin 1, pin 2, and pin 3 of the benefit selection switch U2 and the output end of the operational amplifier U1B are respectively connected to the other end of the capacitor C11 and one end of the capacitor C4, and the other end of the capacitor C4 is connected to one end of the resistor R7; the other end of the resistor R3 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is respectively connected to one end of the resistor R5, one end of the capacitor C5 and the audio input interface terminal IN1_P; the other end of the resistor R9 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is respectively connected to one end of the resistor R8, one end of the capacitor C10 and the audio input interface terminal IN1_N, and the other ends of the resistor R6, the other end of R5, the other end of R8, the other end of the capacitor C7, the other end of C5, and the other end of C10 are respectively grounded GND.

[0060] The positive input terminal of the operational amplifier U1A is grounded, the negative input terminal of the operational amplifier U1A is respectively connected to the other end of the resistor R7, one end of the capacitor C8, and one end of the resistor R11, the output terminal of the operational amplifier U1A is respectively connected to one end of the resistor R4, the other end of the capacitor C8, and the other end of the resistor R11, the other end of the resistor R4 corresponds to the output terminal LIN / MIC_ADUIO of the audio input module, that is, the other end of the resistor R4 is connected to the limiting circuit module.

[0061] The above-mentioned audio input module should provide different gain options for different external audio source inputs. The main implementation principle is: when a line input audio source is used, the audio signal is coupled through the audio input interface IN1_P, IN1_N, GND through capacitors C3 and C12, and then connected to resistors R3 and R9 and input to the positive and negative input terminals of the operational amplifier U1B respectively. At the same time, the electronic gain selection switch U2 will select the LIN_AP corresponding to pin 1 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2. The resistor R12 is used as the gain feedback resistor for the line input audio source. After the first stage amplification, the output of the operational amplifier U1B is coupled with the capacitor C4 and output to the operational amplifier U1A for the second stage operational amplification, and finally sent to the next stage limiting circuit module through the output terminal LIN / MIC_ADUIO of the audio input module.

[0062] When a microphone is used to input the sound source, the audio signal is coupled through the audio input interface IN1_P, IN1_N, GND through capacitors C3 and C12, and then connected to resistors R3 and R9 and input to the positive and negative input terminals of the operational amplifier U1B respectively. At the same time, the electronic gain selection switch U2 will select the MIC_AP corresponding to pin 2 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2. The resistor R10 is used as the gain feedback resistor when the microphone is inputting the sound source. After the first stage of amplification, the output of the operational amplifier U1B is coupled with the capacitor C4 and output to the operational amplifier U1A for the second stage of operational amplification, and finally sent to the next stage of limiting circuit module through the output terminal LIN / MIC_ADUIO of the audio input module.

[0063] Among them, the model of the electronic gain selection switch U2 is HCF4052. The level configuration of pins 9 and 10 in the electronic gain selection switch U2 is used to control the LIN_AP corresponding to pin 1 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2, or the MIC_AP corresponding to pin 2 of the electronic gain selection switch U2 and the COM_AP network corresponding to pin 3 of the electronic gain selection switch U2.

[0064] In one embodiment, the method of step S130 specifically comprises the following operations:

[0065] The three preset noise detection frequencies are 230Hz, 600Hz, and 1100Hz;

[0066] The sampling time is preset to 30 seconds to collect environmental noise data, and the collected noise data is preprocessed, such as filtering and denoising, signal amplification, etc., to improve the quality and availability of noise data;

[0067] Analyze the noise data and obtain the noise level at each frequency point by calculating the noise power spectral density (PSD);

[0068] The noise levels of the three noise detection frequency points are integrated, and the noise value of the current environment is obtained by taking the average or median.

[0069] In one embodiment, the method of step S140 is specifically performed as follows:

[0070] Obtaining a gain adjustment coefficient (CN-RN) / GR based on a comparison result between the detected noise value and a preset reference noise value;

[0071] By performing gain adjustment on the audio signal AF processed by the limiting circuit module through the gain adjustment coefficient, the audio signal AL=[1+(CN-RN) / GR]*AF sent to the sound reinforcement module can be obtained, wherein CN is the noise value of the place where the sound reinforcement module is located detected by the noise detection module, RN is the preset reference noise value, GR (Gain Ratio) is the preset gain ratio, which can be selected as 6:3, 5:3, 4:3, 3:3, 3:4, 3:5, 3:6, Min.Gain≤CN≤Max.Gain, Min.Gain≤RN≤Max.Gain, Min.Gain=-18~-3DB, Max.Gain=-15~-0DB.

[0072] In summary, the present invention provides an audio system and method for adjusting an audio signal in real time according to ambient noise. The noise detection module detects the noise value of the place where the sound reinforcement module is located, and the gain adjustment module performs gain adjustment on the audio signal based on the comparison result between the detected noise value and the preset reference noise value. Therefore, during the use of the audio system, the output volume of the sound reinforcement module is automatically adjusted according to the ambient noise, thereby effectively improving the user experience.

[0073] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0074] In the several embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of each unit is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0075] The steps in the method of the embodiment of the present invention can be adjusted in order, merged and deleted according to actual needs. The units in the device of the embodiment of the present invention can be merged, divided and deleted according to actual needs. In addition, the functional units in the various embodiments of the present invention can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for a computer device (which can be a personal computer, a terminal, or a network device, etc.) to perform all or part of the steps of the method described in the various embodiments of the present invention.

[0076] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. An audio system for adjusting audio input in real time according to ambient noise, characterized in that: It includes an audio input module, a limiting circuit module, a gain adjustment module and a noise detection module. The audio input module is used to perform preliminary processing on the audio signal. The limiting circuit module is electrically connected to the audio input module and is used to perform appropriate amplitude limitation on the audio signal processed by the audio input module. The noise detection module is connected to the gain adjustment module. The gain adjustment module is connected to the limiting circuit module. The noise detection module is used to detect the external environmental noise value. The gain adjustment module is used to perform gain adjustment on the audio signal processed by the limiting circuit module based on the comparison result between the detected noise value and the preset reference noise value. The gain adjustment module is used to connect to the sound reinforcement module.

2. The audio system for adjusting audio input in real time according to ambient noise according to claim 1, characterized in that: The audio input module is also used to identify the input mode of external audio.

3. The audio system for adjusting audio input in real time according to ambient noise according to claim 2, characterized in that: The audio input interface of the audio input module is a common interface for line input and microphone input.

4. The audio system for adjusting audio input in real time according to environmental noise according to claim 3, characterized in that: The audio input module includes operational amplifiers U1B, U1A, resistors R5, R8, R3, R6, R9, R10, R12, R7, R11, R4, capacitors C5, C10, C3, C12, C7, C6, C11, C4, C8, and an electronic gain selection switch U2. The positive input end of the operational amplifier U1B is respectively connected to one end of the resistor R3, one end of the capacitor C6, one end of the resistor R6, and one end of the capacitor C7. The negative input end of the operational amplifier U1B is respectively connected to one end of the resistor R9, one end of the resistor R10, one end of the resistor R12 and the other end of the capacitor C6 and one end of the capacitor C11. The other end of the capacitor C11, the resistor R10, and the resistor R12 are respectively connected to the electronic gain selection switch U2. Pin 1, pin 2, and pin 3 of the gain selection switch U2 and the output end of the operational amplifier U1B are respectively connected to the other end of the capacitor C11 and one end of the capacitor C4, and the other end of the capacitor C4 is connected to one end of the resistor R7; the other end of the resistor R3 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is respectively connected to one end of the resistor R5, one end of the capacitor C5, and the audio input interface terminal IN1_P; the other end of the resistor R9 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is respectively connected to one end of the resistor R8, one end of the capacitor C10, and the audio input interface terminal IN1_N, and the other ends of the resistor R6, the other end of R5, the other end of R8, the other end of the capacitor C7, the other end of C5, and the other end of C10 are respectively grounded GND; The positive input terminal of the operational amplifier U1A is grounded, the negative input terminal of the operational amplifier U1A is respectively connected to the other end of the resistor R7, one end of the capacitor C8, and one end of the resistor R11, the output terminal of the operational amplifier U1A is respectively connected to one end of the resistor R4, the other end of the capacitor C8, and the other end of the resistor R11, and the other end of the resistor R4 corresponds to the output terminal LIN / MIC_ADUIO of the audio input module.

5. The audio system for adjusting audio input in real time according to environmental noise according to claim 1, characterized in that: The limiting circuit module is a limiting chip IC1, the output end LIN / MIC_ADUIO of the audio input module is coupled into the input pin 3 of the limiting chip IC1 through the capacitor C14, the output pin 2 of the limiting chip IC1 is connected to the gain adjustment module through the capacitor C13, the pin 6 of the limiting chip IC1 is connected to the resistors R13 and R14 and then to the ground, the pin 4 of the limiting chip IC1 is connected to the capacitor C15 and then to the ground, and the pin 5 of the limiting chip IC1 is connected to the capacitor C16 and then to the ground.

6. A method for adjusting audio input in real time according to ambient noise, characterized in that: include Step S110, receiving and preliminarily processing an external input audio signal through an audio input module; Step S120, receiving the audio signal sent by the audio input module through the limiting circuit module and performing limiting processing; Step S130, detecting the noise value of the place where the sound reinforcement module is located by the noise detection module; Step S140: receiving the audio signal processed by the limiting circuit module through the gain adjustment module, and performing gain adjustment on the audio signal based on a comparison result between the detected noise value and a preset reference noise value.

7. The method for adjusting audio input in real time according to environmental noise according to claim 6, characterized in that: Also includes Step S110 - 1 , identifying the input mode of external audio through the audio input module; wherein the input mode includes a common line input mode and a microphone input mode.

8. The method for adjusting audio input in real time according to environmental noise according to claim 6, characterized in that: The audio input module includes operational amplifiers U1B, U1A, resistors R5, R8, R3, R6, R9, R10, R12, R7, R11, R4, capacitors C5, C10, C3, C12, C7, C6, C11, C4, C8, and an electronic gain selection switch U2. The positive input end of the operational amplifier U1B is respectively connected to one end of the resistor R3, one end of the capacitor C6, one end of the resistor R6, and one end of the capacitor C7. The negative input end of the operational amplifier U1B is respectively connected to one end of the resistor R9, one end of the resistor R10, one end of the resistor R12 and the other end of the capacitor C6 and one end of the capacitor C11. The other end of the capacitor C11, the resistor R10, and the resistor R12 are respectively connected to the electronic gain selection switch U2. Pin 1, pin 2, and pin 3 of the gain selection switch U2 and the output end of the operational amplifier U1B are respectively connected to the other end of the capacitor C11 and one end of the capacitor C4, and the other end of the capacitor C4 is connected to one end of the resistor R7; the other end of the resistor R3 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is respectively connected to one end of the resistor R5, one end of the capacitor C5, and the audio input interface terminal IN1_P; the other end of the resistor R9 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is respectively connected to one end of the resistor R8, one end of the capacitor C10, and the audio input interface terminal IN1_N, and the other ends of the resistor R6, the other end of R5, the other end of R8, the other end of the capacitor C7, the other end of C5, and the other end of C10 are respectively grounded GND; The positive input terminal of the operational amplifier U1A is grounded, the negative input terminal of the operational amplifier U1A is respectively connected to the other end of the resistor R7, one end of the capacitor C8, and one end of the resistor R11, the output terminal of the operational amplifier U1A is respectively connected to one end of the resistor R4, the other end of the capacitor C8, and the other end of the resistor R11, and the other end of the resistor R4 corresponds to the output terminal LIN / MIC_ADUIO of the audio input module.

9. The method for adjusting audio input in real time according to environmental noise according to claim 6, characterized in that: The method of step S130 is specifically performed as follows: Preset three noise detection frequencies; Collect environmental noise data and pre-process the collected noise data; Analyze the noise data and obtain the noise level at each frequency point by calculating the noise power spectrum density; The noise levels of the three noise detection frequency points are integrated, and the noise value of the current environment is obtained by taking the average or median.

10. The method for adjusting audio input in real time according to environmental noise according to claim 6, characterized in that: The method of step S140 is specifically performed as follows: Obtaining a gain adjustment coefficient (CN-RN) / GR based on a comparison result between the detected noise value and a preset reference noise value; By performing gain adjustment on the audio signal AF processed by the limiting circuit module through the gain adjustment coefficient, the audio signal AL=[1+(CN-RN) / GR]*AF sent to the sound reinforcement module can be obtained, wherein CN is the noise value of the place where the sound reinforcement module is located detected by the noise detection module, RN is the preset reference noise value, and GR is the preset gain ratio.

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