Navigation:  Preferences > Network page > How to (network) > How to: do not play sound when new note arrives

Right click on program icon appears in system notification area and choose "Preferences" menu item from pop-up menu or click on button on PNotes Control Panel.

When "Preferences" dialog appears, choose "Network" page.

 

To prevent playing sound when new note arrives check the appropriate check box:

 

Default value: unchecked.