Asus BE24EQSK 23.8" 16:9 IPS Business Monitor with Webcam - Manual (Page 26)

2-12 Chapter 2: Setup
If the Only HDMI or DP cable are connected from monitor to the computer, check
ASUS BE/C6 Monitor Set Default , the monitor speaker will be used as the default
setting.
Sound setting set the ASUS BE/C6 as default.