You can stop the beeps by turning off the Panel Piezo Beeps and Trouble Beeps in the Siren Options menu.
Here are the steps:
1. Select the ''gear'' or ''settings'' icon on the bottom right side of the screen.
2.Using the down arrow on the lower right hand side of the screen scroll down 3 times and on the bottom of the page you will see the option ''Programming'', press the enter icon located to the right of it.
3. The new screen will ask you for your installer code, on this panel that is 4,3,2,1 by default, then press the ''ok'' button to confirm the code.
4. That will open up the programming menu, you will want to select ''Siren options'' which is on the lower left side on this page.
5. On the new page make sure that "trouble beeps" are unchecked.
6. Press the ''Close'' button on the top right side of the page twice and that will take you back out of programming.
Congratulations, you have successfully turn off the trouble beeps on your Simon XTi alarm system!