If there is a crackle on your audio, if it cuts in and out while you are speaking, or if it makes you sound like a robot then:
This may be a physical problem. If something is rubbing the microphone or something connected to it (such as its cable), physically prevent that.
This could be a bandwidth problem. You may be able to resolve this by reducing things which are using up bandwidth:
- Pause downloads
- Ask other members of the household not to stream video
- Disable your video in Discord
This might be an issue with Discord detecting your voice. Go into the configuration and set it to Push to Talk.