The amount of sound in the course varies with product. Typequick Professional has a lot of sound clips in the introduction lessons, but limited sound in the remaining Basic Keyboard lessons, and none in the Advanced courses.
Sound could be turned off in the Settings section of the program (accessed from the main menu screen immediately after logging on).
Sound could also be disabled by the computer or by a server (if accessing is done through Citrix or Microsoft Terminal Services).
Check that you are able to get sounds through your Internet browser and Adobe Flashplayer by trying to play a Flash-based movie clip from a site like YouTube.