That's pretty much what you hear when you play the ROM file in GoldWave or Audacity, hence why you can also hear the samples (playing at too high of a sample rate here) at a certain point.
So what happened at 8:47 is that the game played back every PCM sample in the cartridge ROM at high speed. Also I think it may have attempted to play back some level data as audio, too.
Recent fun fact discovery: Those "glitched" titles that pop-up at 1:47 are actually part of the game. They're just not seen due to clever use of the skew trick.
When I was little I had a Buzz Lightyear toy that I became terrified of for a very long time after it ran low on batteries and it's voice got all deep and slow... This is a similar sort of fear.
Just imagine that your child or your son or daughter is playing toy story on the Sega genesis in the middle of the night and all the sudden this happens
I remember one time I was playing the level where you are riding on RC car (third last level) and it started playing the music from the level with the skateboard. I thought I'd just imagined it, but that seems like it may have been true
Hi GambadoGamers, if you can see this, please make more videos like this if you can, it really cheers me up. P.S. I can't stop coming back to this video. XD