On slide 1 of attached file:
-selected first line of text by triple clicking,
-double-clicked the first text effect in the effect ordering box (where you can
reorder them up or down) to open "effect options" dialogue box.
-on the "effect" tab, the defaults appear to be: no sound, don't dim, letter by
letter, and 0.0% delay between characters.
-I would like to change it to 2.5% delay between characters, but whether I type
it in or use the up/down arrow buttons, after I close the effect options
dialogue box, it appears to have forgotten my choice, and it does not play as I
hoped. When I reopen the effect options dialogue box, it defaults back to 0.0%

The most puzzling thing to me is that this effect works fine on other slides in
the same file!