When you see the word 'PLOOP!' written with the instruction that it is a sound effect, what noise do you hear?  In this layout drawing (graphite on 12 field animation paper) by Chuck Jones from his 1959 short animated cartoon, "Baton Bunny" and debuting in theaters nationwide on January 10th we find Bugs Bunny struggling with loose cufflinks, a pesky fly and a score (score!) that demands the utmost from its conductor.  Our intrepid rabbit is, of course, up to the task.  

Jones' sound effect note would have been heeded by his long-time sound editor (and film editor) Tregoweth "Treg" Brown (1899-1984) and we're sure he knew exactly what was called for in this scene as Jones and his crew by this time were of a mind, so attuned to each other that the slightest gesture or the least of clues would automatically be interpreted properly.