Nintendo continues to tease the Switch 2’s C button with a new video highlighting a Mii-like sound effect ...

Press and hold the Ctrl key while you select the transition slides you want to add the sound. On the Transition tab in the Timing group, click the Sound button and select a sound from the list.

With just a few dollars in parts and whatever old speaker or other enclosure you have lying around, you can make a sound effects button box.