Voice Chat

Killer Queen Black supports in-game voice chat natively. You do not need the Nintendo Mobile App to use voice chat, and it is not supported or possible to do so.

Alternately, if you are the Killer Queen Black Discord server, and are teaming up, you can use a voice channel instead.

Voice Chat Options
To access voice chat options, from the main screen go to options -> voicechat

Note that teams tend disable push to talk, leaving the channel open at all times.
 * Connect to voice chat: Enable or disable voice chat completely
 * Push to talk: Enabling this requires you to press a button (usually R2 on gamepad) to speak. Push to talk is enabled by default (at least on Nintendo Switch).
 * Show in-game speaker overlay: An indicator on left side of screen showing who is talking/can hear voice chat.
 * Chat volume: How loud voice chat will be

Muting Players
To mute one or more members of your team, press start/+ (Switch) or escape (PC) to pull up a player listing where this is possible.

Wired Headsets
The simplest approach is to simply plug in an earbud & mic with a 3 ring trrs connector into the headphot jack of your Switch. This works even in docked mode, if you have a long enough cable!

Bluetooth Headsets
Certain bluetooth headsets now work with the Nintendo Switch. Here is a full list of known Switch-compatible bluetooth headsets.

Testing Mic Levels Before Entering Play
Unfortunately this is not possible to do currently within Killer Queen Black on the Nintendo Switch.

(source @Viotech3#8512 on Discord)