I was wondering if anyone has used different sounds when training multiple dogs?

I came across this Clicker+, with 4 possible sounds. I only need 2, as I have Lacey training and will start Marlin soon.

Do you think it important to use different sounds for 2 dogs?

Here it is at Clean Run:
http://www.cleanrun.com/index.cfm?fu...5&ParentCat=57

And here is where you can hear the 4 sounds it makes:
http://www.clickertraining.com/node/360