Bouncing ball algorithm

Hello,

I am building a kind of beat-repeater where a sound is repeated over time but speeding up or slowing down by a certain factor. I have now run into problems, as I would like to know the total amount of time it would take for the sound to repeat x number of times by a scaling factor, starting from a specified period between the first and second sound.

I have the feeling I should be using the expr object and have it calculate a logarithmic growth or decay where I can calculate the total amount of time, by knowing the initial period between the first and the second sound, the number of repetitions as well as the scaling factor and even though this is probably a simple equation, my math skills are not up for it.

Any help would be appreciated.

Thanks, Adam