Yes, monitors can play sound through HDMI. Most modern monitors are equipped with built-in speakers and HDMI ports, which allow them to receive audio signals from a wide range of devices such as computers, game consoles, and Blu-Ray players. When connecting these devices to the monitor via HDMI, the audio signal is transmitted along with the video signal, allowing sound to be played through the monitor’s speakers. However, the sound quality and loudness may vary depending on the specific models of the devices and the monitor.