Are you talking about the native Windows 10 sound / volume bar
OR
Something proprietary that was installed from the factory by Toshiba
IF the former
Do you have the speaker icon in the notification area, bottom right of screen on taskbar near the clock
IF not.... right click any blank area of the taskbar and choose "Taskbar settings"
Scroll down to the section labeled "Notification area"
Use the two links there
"Select which icons appear on the taskbar"
AND OR
"Turn system icons on or off"
See if one of those help with your problem.