He can at least hear her cackling, but did he hear everything else like she fantasized? His reaction doesn't feel quite right if he did hear everything, although it may be about right if he had to listen for several hours.
"I assure you dear reader, the 30 page chapter about a minor character that probably will never show up again furiously masturbating to the thought of the MC railing her was 100% necessary for the plot." - Author