DiscRotate is a MenuItem that will control the speed of your optical drives. It is written in Cocoa for Mac OS X Leopard and later. It can help you make optical drive operation much quieter. Upon launching, a drive icon will appear in your menu bar at the top. It will list all installed optical drives and let you choose how much throttling applies to each of them. The green bar shows the current setting, and can be clicked to change the throttling speed. 100% means the minimum drive speed. When using heavily scratched CD/DVDs it is recommended to lower the setting to about 85%. Clicking the CD icon in the list will pause throttling for that particular optical drive.
ApplPi is a stochastic noise machine that creates a soothing background noise for those who can't work in complete silence or need to mask distracting noise. It creates sound similar to any noise machine, but it's more musical and harmonic. Additionally, you can control the frequency (note) of the sound and choose from built-in presets of noise/sound.