How to Disable Sound When Clicking Indicator Buttons in MT4?

 
In my indicators, I use OBJ_BUTTON for creating buttons and I have not implemented any custom sounds for button clicks. However, one of my users mentioned that they hear a sound every time they click a button and asked, "Would you please allow users to turn off the sound of the click button?"

I would really appreciate it if someone could kindly point me to a way to disable this sound directly in MT4, or suggest any workaround if available.
Thanks in advance for your help!