Hello. I can assist you with your question.
What model computer do you have?
Are the speakers built in? If not, do you know the model number of the speakers?
There are a number of troubleshooting measures you can take. It sounds like you are having a problem with a settiing the audio setup vs bacground noise from something else, since muting it solves the problem.
First right click on the speaker icon in the bottom right system tray and then select open volume mixer. See if muting any individual sound channel gets rid of the click. If that doesn't work, then please go to the following page, perform the steps there, and then let me know how you made out. Feel free to ask any questions along the way as well.