changing span value when checkbox is checked and unchecked

I'm wanting to have a span value change when a checkbox is checked, then changed back to the orig value when unchecked.

<input class="form-check-input" type="checkbox" name="ship" value="Expedited" id="exp1">

So, the orig value is 'Standard', I want to change this to 'Expedited' when checked, then 'Standard' if unchecked. How do I go about doing this?