The kill ring keeps more than the latest passage. At the intended destination, M-y after a non-yank command opens a chooser for earlier entries. Use completion or prompt history to inspect candidates, then RET to insert the chosen text. C-g cancels before insertion. These entries may contain private text; use a harmless example when practising or sharing your screen or audio.
Immediately after C-y, the same M-y instead replaces that insertion with an earlier entry. Further consecutive M-y commands cycle through earlier entries, and Emacsvox speaks each inserted candidate. Once you issue a separate reading or movement command, do not assume M-y will still replace the last paste: outside the yank sequence it opens the chooser for another insertion.
To verify a candidate while cycling, listen to the automatic yank feedback. When you decide to keep it, inspect its surroundings normally. If you have already broken the sequence and want a different passage, undo the unwanted insertion, check the destination, and choose again. Repeated C-y inserts more copies; it is not an accept or preview command.
More detail: Yanking earlier kills in the GNU Emacs Manual. Kill-ring history is useful recovery information, not a permanent backup of your work.