Zooming amplitude

Amplitude can be zoomed via the mouse wheel (Shift+wheel), channel rulers, menus, or keyboard shortcuts. Amplitude zoom normally affects all channels at once, but it's also possible to zoom each channel independently, by unchecking the Vertically sync channels option.

Zoom via mouse wheel
Position the mouse cursor over the point of interest, and while holding down the Shift key, spin the wheel up to zoom in (increase amplitude magnification), or down to zoom out (decrease amplitude magnification). By default the zoom centers on the mouse cursor's vertical position, but it can be configured to center on the origin instead, in which case the origin remains stationary and the mouse cursor position is ignored.
Zoom via channel ruler click
Left-click on a channel ruler to zoom in, or right-click on a channel ruler to zoom out. The mouse cursor's vertical position on the channel ruler specifies the point to zoom into or out of. The amount of zoom is determined by the vertical zoom step size.
Zoom area via channel ruler drag
Position the mouse cursor over a channel ruler, at one horizontal border of the area of interest. Now press the left mouse button, and while holding it down, drag the cursor to the area's other horizontal border. Release the left mouse button to zoom into the specified area. To zoom out of the specified area, hold down the Shift key while releasing the left mouse button. Selecting a smaller area causes a bigger jump in magnification. The drag direction can be top-to-bottom or bottom-to-top. During dragging, the cursor changes to a magnifying glass, and horizontal dotted lines indicate the specified area. To cancel a drag, press Esc.
Zoom via menus and keyboard
To reset amplitude zoom so that all the audio fits vertically in the window, select View/Fit Vertically, or press Shift+0. This also resets the channel heights.