ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: melodrama on December 02, 2007, 02:42:14 pm

Title: random question
Post by: melodrama on December 02, 2007, 02:42:14 pm

just a random thought - why does someone's voice sound like a chipmunk (high frequency) when the play speed is increased, and really low when it's slowed down?

Title: Re: random question
Post by: Collin Li on December 02, 2007, 03:27:41 pm

The sound file encodes data that is supposed to model the actual sound waveform.

When you accelerate the sound file, you have to compress that waveform so that it plays in less time. This decreases the wavelength of the sounds you hear, and hence the frequency goes up. The converse is when the sound file is slowed down: dilation of the waveform, and increase in wavelength, hence a low frequency.

Title: Re: random question
Post by: melodrama on December 02, 2007, 07:31:53 pm

LOL thanks coblin. counted on either you or ahmad in answering that. hahaha.