Choose Logic Pro X > Preferences > Audio > General and deselect software monitoring.
How do I mute audio in Logic?
To mute the movie's sound, click-hold on the Movie window, then choose Video/Movie Settings and select Mute from the Video pane's Sound Output menu.
What is software monitoring logic?
Software Monitoring lets you listen to record-enabled channel strips, including the insert effects. ... The potential downside to Software Monitoring can be increased latency due to effects processing. You can turn on Software Monitoring from the Logic Pro Audio Preferences.