Level: Beginner / Intermediate.
May take some patience at first but is an overall simple process.
Hey guys, this is a tutorial that I also made for my digital video II class. If you ever wondered how to remove that “hissing” noise from your video’s audio, then check this out!
In case you don’t want to sit through 9 minutes of me explaining how this process works, I will try to lay it out in steps below. I also used Adobe Premiere Pro CC and Audition CC in this tutorial, however I am pretty sure Audacity has a feature similar to this.
Step 1: Preparation
Ok, so the most important part this is how you set up your video. In order for this method to work, you need to give the camera some time to capture the sound of the room and any hissing that may be caused from your audio settings. Try to lower your gain on your camera or mic and have your subject speak louder to minimize the amount of hiss you get.
Step 2: Import to Premiere/Audition
Once you’re done shooting video, import your clips into Premiere Pro. Right-click the video that you want to remove noise from and scroll down to where it says “Edit in Adobe Audition.” If you don’t have Audition on your machine, then the option will be grayed out. Anyways, Audition should now be open and you should be looking at the sound wave of your video.
Step 3: Isolate and Capture the Noise
What you want to do is find a portion of the audio near the beginning that only has the “noise” you want to get rid of. Remember how I said to let the camera roll a bit before you actually start shooting? Yea, this is why. It makes capturing the noise print much easier and cleaner. It should have a very small amplitude/wave height compared to the rest of the audio. Click and drag to highlight a section of the audio that only has this noise. Once you have a good chunk of noise selected, press Shift + P to capture the noise print. Additionally, you can go to Effects -> Noise Reduction/Restoration -> Capture Noise Print.
Step 4: Remove the Noise
First, before we go any further, make sure you no longer have the “noise” section of your audio selected. When dealing with effects, whatever you do will only be applied to what you have selected. Either highlight the whole clip or have nothing selected, as this defaults the effects to be applied to the whole track. Anyways, go back up to Effects in the menu bar, and go back to the Noise Reduction/Restoration tab. In here you will see another option called “Noise Reduction (process).” You can also just hit Shift + command + P. This is going to bring up a window that looks something like this:
For the purpose of this tutorial, you only need to worry about the “Noise Reduction” and “Reduce by” options near the middle. Typically, 70% noise reduction and reduce by ~40 dB works pretty well. There is no set ratio that works all the time, but this setting will get you started. Be careful to how much noise you are taking out because you may make the rest of your audio sound funky. This is a destructive process, which means that we are taking out frequencies that we sampled earlier from the noise portion of the audio, so be careful with how much you reduce the noise by.
Step 5: Finish
Ok, so hopefully you have come up with a setting that works well and your audio sounds a bit cleaner. All you need to do now is save your work in Audition and go back to Premiere Pro. You’ll notice the audio track is now green instead of blue. Everything we did in Audition automatically affects Premiere as well. However, maybe you couldn’t get a good sample or you couldn’t take out too much noise without messing up your speaker’s audio (this is usually trickier with people who have higher voices, like girls). You can add some instrumental track on top of the audio and lower the volume so it doesn’t distract from the main content of the video. The noise will be there, but less noticeable. Additionally, if audio quality is a huge part to your project, you may want to invest in some mic’s.
I hope this tutorial was helpful for you.