The common audio processing of human voice generally includes the following aspects

(it is important to pay attention to the order):

　　1.EQ：

EQ is equilibrium. Due to the differences in the pickup curve of the microphone and the voice characteristics of the singer, it is generally handled appropriately according to the practical effect of the recorded voice. For example, some singers sound too sharp, some sound very stuffy, some have a heavy nasal sound, and some have a heavy lip and tooth sound. These are the auditory differences caused by the imbalance of the strength of each frequency band. It can equalize (increase or decrease) the sound signal of each frequency band through EQ, which can play an improved effect.

2. Motivator:

The stimulator, also known as harmonic generator, can add some random harmonics in some frequency bands of sound. Appropriate encouragement will bring beautification to the sound. The difference between the stimulator and EQ is that EQ only adjusts the signal strength of some frequency bands, while the stimulator adds new acoustic components in some frequency bands. However, inappropriate encouragement has a damaging effect on the sound, which will make the sound very "dirty", so many people often do not do encouragement.

3. Constrictor (pressure limiter):

The compressor can actively adjust the dynamic scale of sound level. Generally speaking, it is to actively process all sound signals on the time track as follows: when the sound is small, increase the volume according to the pre-adjusted parameters; when the sound is large beyond a certain limit, start to tighten and reduce the volume according to the proportion of the pre-set parameters, The result is to change the dynamic scale of the whole sound track (the difference between high volume and low volume). Usually, the effect of the pressure limiter is to reduce the dynamic scale. After the pressure limit, the sound sounds fuller and more powerful. It doesn't bother where the sound is small, and it doesn't shock where the sound is large.

4. Reverberators:

The reverberator can beautify the sound, make the sound sound have a sense of space, and the sound is round and transparent.

The following methods are commonly used for noise removal:

1. Noise door:

Set the threshold value of a level, filter out all the signal levels below this threshold, and pass through all the signal levels above the threshold value (here, the signal level refers to the level of the sum of signal and noise levels). This kind of sound data with high signal-to-noise ratio does not need to be denoised. Rvox in wave plug-in is the effector of such a noise gate. How many parameters are appropriate? It is generally about - 50 ~ - 40dB, but the actual background noise is not certain, so you need to try it yourself. The correct position is that you can't hear the set noise, but the small sound made by human voice can't be filtered out.

2. Sampling denoising method:

This is a useful way for professional audio processing software to remove the continuous and stable set noise. The principle of noise removal is to sample the waveform samples of noise, and then analyze the waveform and sampled noise samples of the whole section of data to actively remove noise. The advantage of this noise removal is that it can completely remove the noise, but the disadvantage is that it can damage the original human voice quality. The lower the signal-to-noise ratio, the greater the damage. After this noise removal, the sound has a strong metallic smell. The key to this problem is to control the voice as high as possible in the early stage.

3. Other noise removal methods:

Analyze the frequency band of the noise place with the spectrum, and attenuate the frequency band signal level of the bottom noise place through the adjustment of Eq. However, the signals of the original vocal band are also attenuated, which will pose a new problem, so they are also used less.

EQ treatment:

The spectrum distribution of human voice source is quite special. As far as its pronunciation method is concerned, it has three parts: first, the music caused by vocal cord sensation. The pronunciation of this part is sensitive, and the spectrum changes greatly with different pitches and pronunciation methods; The second is the low-frequency Kai tone generated by nasal consensus. Frequency equalization can roughly separate these three parts of the spectrum. The frequency band used for nasal tone conditioning is below 500Hz, the midpoint frequency of equalization is generally 80-150hz, and the equalization bandwidth is 4 octaves.

For example, 100Hz can be set as the midpoint of frequency equalization, the equalization curve should transition steeply from 100-400hz, and the conditioning scale of equalization gain can be + 10dB ~ - 6dB. We should be reminded that the monitoring speaker during the adjustment of this project shall not use the box with weak low-frequency pronunciation, so as to prevent the nasal sound from being exacerbated unintentionally. The frequency spectrum of human voice and dental sound is more than 4kHz. Since this frequency band includes part of the music frequency spectrum, it is recommended that the frequency band for conditioning tooth sound should be 6 ~ 16KHz, the equalization bandwidth should be 3 octaves, the equalization midpoint frequency is generally 1 / 2 octaves, and the equalization midpoint frequency is 6800hz. The equalization gain is low and can be adjusted down to - 10dB.

From the above analysis, it can be seen that during the frequency equalization of human voice, the broadband equalization with steep curve shall be used as much as possible to improve the frequency band in order to highlight a certain sound feeling. This is to make the spectrum distribution of nasal, musical and dental sounds uniform and coherent, so as to make their pronunciation natural and smooth.

The improvement of 1 / 2 octave narrow-band equalization is easy to make the human sound source strange. Although this equalization method can greatly change the sound color of the sound source, if it is not for special effects, the equalization of singing pronunciation should be based on the natural sound feeling. In order to carry out specific effect processing on the basis of not damaging the natural sense of human voice, the equalization processing of 1 / 5 octave frequency range can be used. Specifically, there are the following scenes.

(1) due to narrow sound sense and lack of thickness, the attenuation treatment of 1 / 5 octave can be applied at 800Hz, and the maximum attenuation value can reach - 8dB.

(2) the sound feeling is very bright, but it is weak and lacks penetration. The attenuation treatment of 1 / 5 octave can be applied at 6800hz, and the maximum attenuation value is - 3dB.

(3) the sound sense of rolling tongue and toothed sound is sharp, and the "Shh" sound lacks clarity. It can be attenuated by 1 / 5 octave at 6800hz, and the maximum attenuation value can reach - 6dB.

For the equalization of sound source, it is better to use the equalizer that can display the equalization curve. For example, the equalizer of all digital mixer has the function of displaying the equalization curve. In this way, the shape of the equalization curve can be seen during the equalization process, which brings convenience for future readjustment.

Generally, the equalization gain adjustment button on the equalizer of digital mixer is indicated by "g", the equalization frequency adjustment button is indicated by "F", and the equalization bandwidth adjustment button is identified by "F" or "Q".

Article source: Jiangmen recording production http://www.sjttv.com