Sound can be played by Genero applications through the playSound front-call. Like images, the key point is to get the sound file from the back-end to the front-end. Your sound file will typically be bundled in with the rest of your application files on the back-end server but needs to be on the front-end server in order for the end user to hear the sound.
To learn more about the playing of sound in a Genero application, read
https://4js.com/ask-reuben/ig-131/