When you are recording audios, it is unavoidable that you can get some unwanted noise. It doesn’t mean you can’t minimize it or even remove it though. In fact, there are a lot of tools and applications that exists which can help you remove those unwanted noise. You just need to choose ones that are suitable for your recorded file.
Noise can be found everywhere and can be obtained in any different sources. They can be classified into two types—random noise and the constant noise. Random noises are those that came from the sounds of a person, nature, etc. while constant noise are those that came from microphones, transformers, air conditioners, etc. These are the noise that any audio editor would face and fortunately for them, there are a lot of techniques and tools that are easy to use in eliminating these two types of noise. Truthfully though, it does not purely mean that you can remove all the noise in your audio recording but rather you can polish them in an acceptable manner.
The noise gate
Noise gate is one of the common ways in eliminating unwanted noise that is perceptible if ever the signal of the audio is at minimal degree. As its name suggests, it is a tool that obstructs noise and this is done when the gate open as soon as the signal above the threshold increases and when the signal decreases below the threshold, the gate will then closes. This will then minimize the unwanted noise in your audio and will allow the chosen parts to appear.
Though it would only work efficiently when the level of the noise is at minimal level and if the preferred audio covered the unwanted noise as the gate opens. The noise can only be covered by your preferred audio only if the chosen sounds are much higher than the unwanted noise. If the preferred audio is low while the noise is high, then it is likely that the noise will still be perceptible.
It is commonly used when recording musical instruments such as drums and guitars as it can help minimize and remove the unwanted noise (hum, hiss, etc.) that is being produced when these instruments stop playing.
It works just as same as what the noise gate does. It minimizes the unwanted noise to appear in your audio. The difference though is that it can increase the level of the sounds that are already in high levels and decreases the sounds that are already at low levels. This is commendable when recording vocals as it can add a fine distinction to the musician’s performance. Expanders can minimize the unwanted noise without negatively affecting the quality of your audio produce a rather more natural sound.
It is used in controlling dynamics. Compressors can make the audio at both high pitch and low pitch at a reasonably levels making it volume-wise. This is done through decreasing the signals above the threshold and increasing the low signals. Its explanation though may seem easy but it is different when you are using it as it needs a little practice and a good listening skills. Compression is commonly used in either recording or in band performances.
This is a software audio editor application that has a lot of features including a noise background reduction. The method of noise reduction is through the use of Fourier analysis . It locates the unwanted background noise in the quiet parts in which you have selected which is then referred to as the frequency spectrum of the sound. As you minimize the unwanted noise from the audio, the Fourier analysis will then locate the frequency spectrum in each parts of the audio. Pure tones that are not at high levels than their regular levels are minimized. In simple terms, the notes of the guitars or a human voice are maintained in its levels while the unwanted background noise is minimized. This kind of technique is referred to as spectral noise gating .
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Audacity though cannot control a wide range of dynamics as compressors can. It can also does not sustain instrument Virtual Studio Technology (VST) plug-ins.