Here we'll address what's going on with Discord's two voice input modes, Push-to-Talk and Voice Activity. To access either of these methods, just maneuver through your user settings into the "voice" tab.
Note: If you're having trouble with Push-to-Talk while running a game in Administrator mode, check out this article.
Mode 1: Voice Activity
This is most likely the more familiar method for users. There's only one setting to mess with here, and that's input sensitivity!
This guy's the culprit.
Chances are, if you're using the desktop client, the "Automatically Determine Input Sensitivity" has impacted your audio in some way, shape, or form.
If your mic jumps from too loud to too soft, or some of your voice is getting cut off at the end of sentences, uncheck this box!
Why's that? Essentially what's happening is that Discord is trying to adjust your mic to an ideal speaking level based on the volume of what's coming into your mic. While Discord is usually pretty good at this, some of you guys might have some serious room noise, or wide variances in speaking volume.
When you do uncheck the box, you'll be given the option to adjust your input sensitivity by yourself.
The key here is to leave the sensitivity marker high enough that nothing is transmitted when you're not speaking:
Make sure the bar is only yellow when you're not speaking.
But still low enough so that it doesn't cut out your voice when you speak softly:
Remember, we want to put the sensitivity marker right between your softest speaking voice and any other noise coming through. This will take some tweaking on your part!
Important note about Voice Activity mode: due to how Voice Activity functions, there is an inherent 200ms delay, plus the distance you are from the active server.
Mode 2: Push-to-Talk
Gamer's classic. Push-to-Talk (PTT) changes things up a bit, in the sense that Discord doesn't pass any incoming audio at all unless you press and hold a dedicated "PTT key".
Only a few things we need to tweak here. Since we've got the input mode selected already, all that's standing between us and sharing our innermost thoughts with our buddies is setting a keybind. To do this, just click on the right box, and press your desired PTT key.
Flashing red border means you're good to go
Why are Mac commands so weird?
Awesome. Now we're set.
Once your desired PTT key is in the box, you're ready to begin pushing to talking.
Last point on Push-to-Talk: The PTT Release Delay slider.
This important tool affects how long PTT waits to cut off audio after you let go of your dedicated keybind. Think of PTT like a door; your keybind is what opens the door, and the Release Delay is how long it takes for that door to close. Door closed = no audio passes through.
Oh, and remember how we have that pesky 200ms delay from Voice Activity? Guess what? Push-to-Talk has 0. Zero. Zilch. Nada. Pretty sweet.
Important note #2: Push-to-Talk only works in the browser app when the window is in focus. If you want to use PTT system wide, you'll have to download the desktop client!
You've now officially passed your first class in Discord's voice input methods! Get out there and proclaim your awesomeness to your friends, with either PTT or Voice Activity.