Method and device for house intelligent active noise reduction

Abstract

The invention relates to a method and a device for the intelligent active noise reduction for a house. The method comprises the following steps: S01) collecting a sound signal in a preset area, and converting the sound signal into a digital sound signal; S02) carrying out FFT (fast Fourier transform) on the digital sound signal, converting the sound signal into a frequency domain from a time domain, analyzing the frequency spectrum of the whole sound signal, dealing with the sound frequency spectrum of non noise in the frequency spectrum of the whole sound signal according to a working mode set by a user, carrying out equiamplitude antiphase calculation on the rest frequency spectrums, and adding a human ear hearing characteristic adaptive algorithm to obtain a new sound frequency spectrum; S03) carrying out inverse FFT operation on the new sound frequency spectrum, and overlaying and combining to obtain a time domain signal; and S04) converting the time frequency signal obtained in S03 into an analog signal, and emitting via a sound production unit. According to the invention, the noise pollution can be effectively eliminated.

Description

technical field [0001] The invention relates to the technical field of noise elimination, in particular to an intelligent active noise reduction method and device for a house. Background technique [0002] Noise, solid waste and air pollution are listed as the three major sources of pollution in the city. The largest source of noise pollution in urban residential areas comes from the noise of cars on the road, as well as cultural, sports and entertainment, and house decoration. Especially in residential areas near the road, schools, hospitals, or office buildings, the noise pollution of the road is more serious, and these noises are characterized by low frequency, burst, and high sound intensity. [0003] At present, urban houses are generally constructed of reinforced concrete + environmentally friendly brick structures, which have a blocking effect on low- and medium-frequency audible sound waves. The noise on the road is generally transmitted to the room through windows....

AI Technical Summary

Problems solved by technology

[0006] (1) The noise reduction effect is not ideal: the commercial vacuum glass on the market can generally reduce noise by 20-30dB, but this is only for higher frequencies to achieve the above effect

However, the effect is not ideal for low and medium frequencies. For this frequency range, it can only be reduced by 5-20dB

[0007] (2) Expensive: Vacuum glass aluminum alloy windows are expensive

[0008] (3) Short life: Vacuum glass is composed of two layers of glass, and there is a vacuum between the two layers of glass. Because of the internal vacuum, it itself bears an atmospheric pressure (about ten meters of water column / square centimeter pressure). If the glass is hit by an external force After that, it is easy to break and leak, and once the vacuum is destroyed, the noise reduction effect will disappear

[0009] (4) Poor comfort: the noise reduction effect of vacuum glass can only be effective when the windows are closed. At present, most houses are not equipped with central air-conditioning equipment, and the ventilation of the house must open the windows

[0011] (1) Poor real-time performance and unsatisfactory noise reduction effect: after collecting sound waves, compare them with the data in the database, search them, and play them if they are found. It takes too much time to eliminate the noise with the sound of the scene, because the propagation speed of the sound can reach 346M / S, and the sound has already propagated a long distance from the beginning of collecting the signal to the last playing of the scene noise, so the reverse sound Hedging against the actual noise sound, if there is an angle, the effect of canceling each other will be poor, resulting in unsatisfactory noise reduction effect

[0012] (2) Accurate reading is not enough, and the use of reverse sound waves will increase noise in some cases: the human ear's auditory characteristics of sound are nonlinear, and the human ear's perception of noise depends not only on the magnitude of the sound intensity, but also on the noise. The influence of frequency, the same two noises, the frequency of the two is different, the amplitude of the noise is also different (sound intensity value), but the human ear feels the same, the human ear is very sensitive to the noise of 1000-8000HZ, the feeling is more Other noises should be strong. In the method of playing reverse scene sound, the process of sound collection is generally judged by the similarity threshold of the sound. The judgment of this similarity threshold does not take into account the auditory characteristics of the human ear. Noises of different frequencies and amplitudes generate reverse scene sounds with different thresholds. When these scene sounds are played, the new scene sounds are reverberated against the original noise sounds. Although the noise is reduced formally, the human Ears feel louder

[0013] (3) Poor adaptability, all sounds will be reduced, including the sounds we need: noise This is a broad definition, a sound may be noise in one situation, and it may not be noise in another situation, such as outdoor Some people are talking to people indoors facing the window, or people are talking outside. Sometimes this sound may be noise, and sometimes it may not be noise. Whether a sound is noise varies with different people or the same person at different times. Segment judgment is completely different, so use the method of playing reverse scene sounds. In any case, no matter whether these sounds are what you need, they are all listed as noise and eliminated.

In practice, this method cannot be used in most cases.

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