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.