All of the buttons on this toolbar perform actions - and with a couple of
exceptions, they're all just shortcuts of existing menu items to save you
Holding the mouse over a tool will show a "tooltip" in case you forget
which one is which.
|Trim away the audio outside the selection|
|Silence the selected audio|
|Fit selection in window - zooms until the selection just fits inside the window.|
|Fit project in window - zooms until all of the audio just fits inside the window.|