An audio noise reduction system and an audio for noise reduction processing in an enclosed space

Abstract

The present invention relates to the technical field of noise-reducing audio systems, and discloses an audio noise reduction system for noise reduction processing in an enclosed space, including a signal processing module, a feedback adjustment module, an audio decoding module, a data storage module, and an audio control module; the signal processing module collects the spectral feature anomaly coefficient, reverberation time, and direct sound to reverberant sound energy ratio between the sound waves collected by the noise detection sensor and the audio feedback by the audio decoding module. The present invention applies different active noise reduction effects by determining whether the audio is in an enclosed space. When the audio is in an enclosed environment, it will apply a reverse sound wave of the environmental noise and the audio reverberation of the speaker to suppress the noise, while when the audio is in an open environment, it will only apply a reverse sound wave of the environmental noise to suppress the noise. This method can effectively reduce the reverberation when the audio is played indoors, and also avoid the problem of dull playback sound caused by adding an additional reverse sound wave of the audio reverberation when playing outdoors.

Description

Technical Field

[0001] The present invention relates to the technical field of noise reduction audio, and in particular to an audio noise reduction system and an audio for noise reduction processing in a closed space. Background Art

[0002] An audio refers to other sounds except human language and music, including sounds of the natural environment, animal sounds, sounds of tools, various sounds made by human actions, etc. An audio mainly includes power amplifiers, peripheral devices (including limiters, effectors, equalizers, VCDs, DVDs, etc.), speakers (loudspeakers, horns), mixing consoles, microphones, display devices, etc. Among them, a speaker is a sound output device, such as a horn or a subwoofer.

[0003] A prior patent discloses an audio system capable of eliminating environmental noise and a noise reduction method for a speaker system (publication number CN107948871A). The audio system includes: an audio receiver, an audio processor, at least two speakers, and further includes a noise reduction module. The noise reduction module includes a sound collection module, a noise judgment module, and a noise reduction circuit. The sound collection module is used to collect the sound signal of the environment and output it to the noise judgment module. The noise judgment module judges the sound signal collected in the sound collection module to determine whether it is noise.

[0004] Since there will be a relatively obvious echo when an audio is played in a closed space, when using active noise reduction in a closed space, the echo needs to be considered as an object of noise reduction, while in an open environment, only external noise needs to be considered as an object of noise reduction. However, in the technology disclosed in the above prior patent, only the judgment of noise is solved, that is, it is determined whether it is noise and suppressed. But if it is the echo of the played audio, and since the echo of the audio has a very high similarity to the audio, it is often difficult to judge it as noise and thus cannot be suppressed. At this time, there will be an obvious echo when playing in a closed space. Summary of the Invention

[0005] The main technical problem to be solved by the present invention is to provide an audio noise reduction system and an audio for noise reduction processing in a closed space, which solves the problems in the above background art.

[0006] To solve the above technical problem, according to one aspect of the present invention, more specifically, an audio noise reduction system for noise reduction processing in a closed space is provided, which is characterized by including: a signal processing module, a feedback adjustment module, an audio decoding module, a data storage module, an audio control module, a noise detection sensor, and a speaker. The noise detection sensor specifically includes a main noise sensor and a secondary noise sensor;

[0007] The signal processing module determines whether the sound system is in an enclosed space based on the spectral feature anomaly coefficient, reverberation time, and direct-to-reverberant sound energy ratio between the sound wave collected by the noise detection sensor and the audio fed back by the audio decoding module;

[0008] The feedback adjustment module is used to actively apply a reverse sound wave signal of environmental noise or speaker audio reverberation to the audio decoding module according to whether the sound system is placed in an enclosed space;

[0009] The audio decoding module is used to parse the audio file stored in the data storage module to control the speaker playback, and also apply a reverse sound wave of environmental noise or speaker audio reverberation according to the feedback of the feedback adjustment module to suppress noise.

[0010] Furthermore, the audio control module is used to adjust the gain, balance, and volume of the audio signal.

[0011] Furthermore, the data storage module is used to store audio files.

[0012] Furthermore, if the signal processing module determines whether the sound system is in an enclosed space based on the spectral feature anomaly coefficient, reverberation time, and direct-to-reverberant sound energy ratio between the sound wave collected by the noise detection sensor and the audio emitted by the speaker, then there is:

[0013] ;

[0014] In the formula, represents the probability coefficient that the sound system is in an enclosed space, represents the spectral feature anomaly coefficient between the sound wave collected by the noise detection sensor and the audio emitted by the speaker, represents the time required for the sound emitted by the speaker to decay from the initial peak to the background noise level, represents the direct-to-reverberant sound energy ratio.

[0015] Furthermore, the signal processing module determines the spectral feature anomaly coefficient between the sound wave collected by the noise detection sensor and the audio fed back by the speaker according to the high-frequency attenuation of the audio emitted by the speaker collected for the second time and the proportion of intermittent or continuous low-frequency noise, and there is:

[0016] ;

[0017] In the formula, represents the spectral feature anomaly coefficient between the sound wave collected by the noise detection sensor and the audio emitted by the speaker, represents the high-frequency attenuation of the audio emitted by the speaker collected for the second time, represents the proportion of intermittent or continuous low-frequency noise.

[0018] Furthermore, when it is the case, it means that the sound speaker is in a closed space, and at this time, noise can be suppressed by the reverse sound waves of the ambient noise and the audio reverberation of the speaker;

[0019] When it is the case, it means that the sound speaker is not in a closed space, and at this time, noise can be suppressed only by the reverse sound waves of the ambient noise.

[0020] Furthermore, the main noise sensor is used to collect the ambient noise outside the sound speaker.

[0021] Furthermore, the secondary noise sensor is used to collect the vibration of the sound speaker housing and the sound emitted by the speaker.

[0022] A sound speaker for noise reduction processing in a closed space includes a hardware board for carrying a sound speaker noise reduction system.

[0023] Beneficial effects:

[0024] 1. According to the present invention, the signal processing module can simply and efficiently determine whether the sound speaker is in a closed space based on the spectral feature anomaly coefficient, reverberation time, and the ratio of direct sound energy to reverberant sound energy between the sound waves collected by the noise detection sensor and the audio emitted by the speaker.

[0025] 2. According to the present invention, different active noise reduction effects are applied by determining whether the sound speaker is in a closed space. When the sound speaker is in a closed environment, reverse sound waves of the ambient noise and the audio reverberation of the speaker are applied to suppress noise, while when the sound speaker is in an open environment, only reverse sound waves of the ambient noise are applied to suppress noise. This method can effectively reduce the reverberation when the sound speaker is played indoors and avoid the problem of dull playback sound caused by adding additional reverse sound waves of audio reverberation when played outdoors. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic internal structure diagram of the sound speaker in the present invention;

[0027] Figure 2 is a schematic diagram of the sound speaker noise reduction system in the present invention;

[0028] Figure 3 is a schematic diagram of the sound speaker in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the technical solutions of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Embodiment 1

[0031] As Figure 1, 3 As shown, according to one aspect of the present invention, there is provided a sound system for noise reduction treatment in an enclosed space, including a hardware board for carrying the sound system noise reduction system. The noise detection sensor specifically includes a main noise sensor and a secondary noise sensor. The main noise sensor is used to collect the ambient noise outside the sound system. The secondary noise sensor is used to collect the vibration of the sound system housing and the sound emitted by the speaker.

[0032] Embodiment 2

[0033] As Figure 1 , 2 shown, a sound system noise reduction system for noise reduction treatment in an enclosed space includes a signal processing module, a feedback adjustment module, an audio decoding module, a data storage module, and an audio control module; the signal processing module determines whether the sound system is in an enclosed space according to the spectral feature anomaly coefficient, reverberation time, and direct-to-reverberant sound energy ratio between the sound wave collected by the noise detection sensor and the audio feedback by the audio decoding module; the feedback adjustment module is used to actively apply a reverse sound wave signal of ambient noise or speaker audio reverberation to the audio decoding module according to whether the sound system is placed in an enclosed space; the audio decoding module is used to parse the audio file stored in the data storage module to control the speaker playback, and also apply a reverse sound wave of ambient noise or speaker audio reverberation according to the feedback of the feedback adjustment module to suppress noise. The audio control module is used to adjust the gain, balance, and volume of the audio signal. The data storage module is used to store audio files. By judging whether the sound system is in an enclosed space, different active noise reduction effects are applied. When the sound system is in an enclosed environment, a reverse sound wave of ambient noise and speaker audio reverberation is applied to suppress noise, while when the sound system is in an open environment, only a reverse sound wave of ambient noise is applied to suppress noise. This method can effectively reduce the reverberation of the sound system when playing indoors and avoid the problem of dull playback sound caused by adding a reverse sound wave of audio reverberation when playing outdoors.

[0034] Embodiment 3

[0035] As Figure 2 shown, the signal processing module determines whether the sound system is in an enclosed space according to the spectral feature anomaly coefficient, reverberation time, and direct-to-reverberant sound energy ratio between the sound wave collected by the noise detection sensor and the audio emitted by the speaker. Then there is:

[0036] ;

[0037] In the formula, represents the probability coefficient that the sound system is in an enclosed space, represents the spectral feature anomaly coefficient between the sound wave collected by the noise detection sensor and the audio emitted by the speaker, Indicates the time required for the sound emitted by the speaker to decay from the initial peak to the background noise level. Indicates the ratio of the direct sound energy to the reverberant sound energy.

[0038] The signal processing module determines the spectral feature anomaly coefficient between the sound wave collected by the noise detection sensor and the audio feedback from the speaker according to the high-frequency attenuation of the audio emitted by the speaker during the second acquisition and the proportion of intermittent or continuous low-frequency noise, as follows:

[0039] ;

[0040] In the formula, Indicates the spectral feature anomaly coefficient between the sound wave collected by the noise detection sensor and the audio emitted by the speaker. Indicates the high-frequency attenuation of the audio emitted by the speaker during the second acquisition. Indicates the proportion of intermittent or continuous low-frequency noise.

[0041] Among them, the probability coefficient of any sound system in a closed space is calculated. Among them, the high-frequency attenuation of the audio emitted by the speaker during the second acquisition takes (unit: dB, high-frequency attenuation = , where is the intensity of the audio emitted by the speaker, is the intensity of the reverberant audio).

[0042] The proportion of intermittent or continuous low-frequency noise takes (c = duration of collecting 20 - 200Hz noise ÷ total duration of the collected noise). Then there is:

[0043] ;

[0044] From the above calculation, it can be known that during the calculation of the probability coefficient of this sound system in a closed space, the spectral feature anomaly coefficient between the sound wave collected by the noise detection sensor and the audio emitted by the speaker is , where the larger the value of m, the greater the probability that the sound system is in a closed space.

[0045] Moreover, during the calculation of the probability coefficient of the sound system in a closed space, the time required for the sound emitted by the speaker to decay from the initial peak to the background noise level takes (unit: s, record the time required for the sound emitted by the speaker at 60dB to the time when the sound received by the noise detection sensor decreases to the background noise level). The ratio of the direct sound energy to the reverberant sound energy takes (energy ratio = (direct sound energy ÷ reverberant sound energy)), then there is:

[0046] ;

[0047] As can be known from the above calculations, the probability coefficient of this audio in a closed space is , then when the audio is in a closed space, at this time, noise can be suppressed by the reverse sound waves of environmental noise and the audio echo of the speaker. And by comparing multiple groups of data, there are:

[0048] Table 1 Parameters of Partial Implementation Data and the Space State of the Audio

[0049]

[0050] As can be known from the data in Table 1 above, when the sample data tends to infinity, the probability coefficient g will be used as the dividing line to determine whether the audio is in a closed space. That is, when , it means that the audio is in a closed space, and at this time, noise can be suppressed by the reverse sound waves of environmental noise and the audio echo of the speaker; when , it means that the audio is not in a closed space, and at this time, noise can be suppressed only by the reverse sound waves of environmental noise.

[0051] The above-described embodiments merely represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. An acoustic noise reduction system for noise reduction in a closed space, characterized in that: include: A signal processing module, a feedback adjustment module, an audio decoding module, a data storage module, an audio control module, a noise detection sensor and a speaker, wherein the noise detection sensor specifically includes a main noise sensor and an auxiliary noise sensor; The signal processing module determines whether the sound is in a closed space based on the spectral characteristic anomaly coefficient, reverberation time, and the ratio of direct sound to reverberation sound energy between the sound waves collected by the noise detection sensor and the audio emitted by the speaker. The calculation formula is: ； In the formula, The probability coefficient indicating that the sound source is in a closed space; It represents the frequency spectrum characteristic anomaly coefficient between the sound waves collected by the noise detection sensor and the audio emitted by the speaker. It indicates the time required for the audio emitted by the speaker to decay from the initial peak to the background noise level, in seconds; It represents the ratio of direct sound to reverberant sound energy. The specific calculation formula of the spectrum characteristic abnormality coefficient is: ； In the formula, Indicates the high-frequency attenuation of the audio emitted by the speaker. Indicates the proportion of intermittent or continuous low-frequency noise; The feedback adjustment module is used to actively apply a reverse sound wave signal of ambient noise or speaker audio reverberation to the audio decoding module according to whether the speaker is placed in a closed space; The audio decoding module is used to parse the audio file stored in the data storage module to control the speaker playback, and also apply the reverse sound wave of the ambient noise or the speaker audio reverberation to suppress the noise according to the feedback of the feedback adjustment module; The audio control module is used to adjust the gain, balance and volume of the audio signal.

2. The acoustic noise reduction system for closed space noise reduction according to claim 1, characterized in that: The data storage module is used to store audio files.

3. The acoustic noise reduction system for closed space noise reduction according to claim 1, characterized in that: when When , it means that the speaker is in a closed space, and the noise can be suppressed by the reverse sound waves of the ambient noise and the speaker audio reverberation; when , it means that the speaker is not in a closed space, and the noise can be suppressed only by the reverse sound waves of the ambient noise.

4. The acoustic noise reduction system for closed space noise reduction according to claim 1, characterized in that: The main noise sensor is used to collect environmental noise outside the speaker.

5. The acoustic noise reduction system for closed space noise reduction according to claim 1, characterized in that: The auxiliary noise sensor is used to collect the vibration of the sound housing and the audio frequency emitted by the speaker.

6. A sound system for noise reduction in a closed space, characterized in that: The audio noise reduction system applied to any one of claims 1 to 5, wherein the audio used for noise reduction processing in a closed space includes a hardware board for carrying the audio noise reduction system.

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