I can not find anything that calls itself a KDE Menu Tool anywhere.
The KDE menu tool is available in several locations.
If you right click on the task bar on the far left hand side just over the menu start button the options that are offered are Menu Edit and Panel Settings. The option you want is the KMENU edit functions. It is almost like the menu and task bar settings for a windows box.
In the menu selections under service and configuration is the GDMSETUP and logon screen menu item. The GDM is the logon display that appears
every time you logon to a linux box. The display can be via KDM or GDM
but the settings are controlled by the GDMSETUP function.
The GDMSETUP sets how and what is displayed as you logon.
The other way to get to the GDMSETUP is while in a terminal logged as ROOT type gdmsetup.
The terminal window will display the logon options and the last tab on the right had side has
a setting for accessibility and sound. The sound is the one that your having the problem with.