Hearing the correct pronunciation wouldn't have changed anything. I have spent hours teaching pronunciation to Japanese students, only to hear them completely revert back to "Katakana English" the very next day. It never fails.
Since were are on the topic of katakana English, I'd like everyone to take a look at a katakana English YouTube video that has over 50 million views! Many people call it the Makudonarudo (McDonald's) video.
Yes! Unfortunately, I have had many classes where the students speak just like this... ("People! People! People!")
Here is another good one. Take a look at this video from 0:59. I have forced my students many times into the exact situation as, "What are you sinking about?" (It is very painful to teach Japanese students to pronounce "think".) Too funny.