Here's how to turn a simple pitch change into a multi-layered effect. The basic idea can be modified to create a range of different voice effects.
This quick tip is taken from the larger project video, Basic Sweep. The full video can be found at:
Step 1: Vocal Track
We need to start with a clean voice track. If you're not happy with any element of your vocals, now is the time to change it.
Make sure that your track has uniform volume and is free of noise before going ahead with the effect.
Step 2: Duplicate Your Voice Track
Keeping a clean copy of your vocal track is a good habit to get into. You may want to layer other effects later on, and need a fresh copy to modify.
Click the panel to the left of your track to highlight the entire track, then hit Ctrl + C to copy.
Click the empty space beneath your track, and hit Ctrl + V to paste.
Mute your original track by selecting the Mute button from the left panel. This will keep it out of the way, so you can listen to your project without it interfering with the playback.
Step 3: Basic Pitch Effect
Click the panel to the left to highlight the new vocal layer, and go to Effect in the menu bar. Select Change Pitch.
Play with the setting until you're happy with the result. The default value is 0, which will make no change. Moving the slider to the left will give you a negative value and make the pitch deeper, and moving it to the right will produce a positive value and a higher pitch.
I find that it's best to apply the effect and listen to the entire track before making a decision. Hit Ctrl + Z to undo the change if you're not happy with it, and return to the Change Pitch effect to try again.
In this example I use -9.
Step 4: Adding Emphasis 1 - Isolating Audio
In this project, I wanted to create a strong emphasis on certain words. We need to isolate those parts before we apply any additional effects.
Copy your vocal track and paste it below.
On the new copy, highlight the parts that you will need to remove. Zoom in by using the Zoom tool, or by hitting Ctrl and scrolling forward on your mouse's scroll wheel. The selection needs to be exact.
Use the Silence Audio tool to silence the selected audio, leaving only those parts you wish to emphasise.
Step 5: Adding Emphasis 2 - Layering Pitch Effects
Select your entire emphasis track, and apply a Change Pitch effect. In my example, I duplicated my original settings, and left it at -9.
Playing back your entire project, you will notice that this creates a dual-voice effect.
Copy this layer and paste it below, then repeat the process of applying a Pitch effect to the new layer.
It's easy to over-do this, so play with the effect until you're happy with the result. You might like to add higher-pitched voice layers as well, for a really dissonant finished effect.
Step 6: Adding Emphasis 3 - Reverb
Select the deepest of your emphasis tracks, and go to Effect on the menu bar. Select Reverb.
It's safe to stick with all of the default settings, and only change the Room Size.
This effect is really easy to over-do. As you can hear in the example, choosing a Room Size value that is too high will make your project sound like you're in a cave. For this project, I chose 10%.
As always, apply your effect and then play back your project to find the values that give you the result you need.
You can also layer this effect in the same way that you layered your Pitch effects. The result can become distorted, but sometimes distortion is exactly what you want. This is a demonic voice, after all.
Step 7: Mix-down and Final Edit
Once you're happy with the end result, mix it down to a single audio file.
In the menu bar, go to File and Export Audio.
I recommend choosing WAV as the file type, as it is lossless. That is to say, it is not compressed, and will not compromise the quality of your project. MP3 is fine for your final result, but at this stage we are still editing.
You can also save your project in its current, mult-layered state for further editing by hitting File, Export Audio. This will create a file in Audacity's AUP format.
Step 8: The Final Edit
Open your mixed-down project in a new window. You shouldn't need to use Normalise or Compressor tools, because most of the effects we've used have been applied evenly to the entire project. The only exception is the areas we've emphasised.
As you can see from the picture and video, the emphasised areas are clipping badly. This is to say, they are reaching a volume that causes distortion.
To fix this, select the entire project. Go to Effect on the menu bar, and select Limiter.
In the Limiter dialog, choose Hard Limit as the Type.
Most of the settings can be left as default. The most important setting is Limit to (dB).
The maximum volume the project can be is 0dB. Setting the Limit to -1dB means that any parts of the selected audio that exceed that -1dB will be reduced, without affecting the rest of the audio. Limiter is a good tool for when you want to preserve the volume of your overall project, but have a few areas that are too loud.
Use the Limiter to bring the blow-out areas down to match the loudest parts of the original audio.
Save your project a final time, and you are done!