The inner workings of Change tempo in Audacity

Hi, I hope this is the correct forum for my questions. If not I assume the mods will move it to the correct place. I’m part of a research project where we have been gauging the reactions of people when subjected to very fast and very slow musical tempi. In the course of this we’ve used Audacity to manipulate the tempo of music files without distorting the pitch (Effects->Change tempo). Now we have come to the part where publication is an option and thus it is necessary to supply some detailed description of how the process is done. And this is where I hope you fine folks on the forum can help me. More specifically I would like to know what Audacity does to the sound file when I press “Ok” on the “Change tempo”-window.

Reviewers have been particualrily keen to know the following details.

it is important to describe clearly how the music examples were manipulated acoustically to change objective tempo. Particularly, I would like to know how well the proportion of time intervals between the onsets of sounds was preserved. I also would like to know whether the rise time, intensity, and spectrum of each percussive sound were preserved reasonably.

I’m hoping that someone here who has a better understanding of the code behind this fine program can help me. I’m looking for detailed descriptions of how the “effect” works.

See here:

Thank you, I tried the Search-function but I must’ve used the wrong keywords. Thanks for the link.