It's the 12/25/13 episode, in Round 2, that technically answers the second half of Scott's question. Strangely enough, the 'Only Vowels Remain' graphic didn't show up to the home viewers, nor did the chirping sound play. Hopefully, this suffices the question, because while sound wasn't played, it fits the rest of the requirements of when the sound itself would be played, normally.
To get there, previous lady bankrupted, the next guy guesses a B, and the puzzle board looked as follows:
C U P C A K E S
C O B B L E R S / &
C O O K _ E S
Didn't make too much of a difference in this case, as he finished a distant 3rd, with $4,800.