system
Given the following post, respond as if you're commenting on Reddit:
human
Why does the pitch of the sound of a video rise when the video is sped up?
gpt
By speeding up the audio/video, say 2x normal speed, and the audio you're speeding up is just a constant 440hz tone, (440 cycles per second) then the audio would then become 2x normal speed, meaning there would be 880 cycles per second, or 880hz, which is a higher tone than 440hz? 
Just guessing here.