Step 1: What you need
A hand operated pump, a sink waste trap and a rubber glove (for the diaphragm)
Step 2: Preparing parts
I cut the bowl down to size by cutting a section out and sticking the 2 end parts back together. drill a small hole in the back of this part so that it isn't fully sealed.
Step 3: The noise maker
At this stage if you blow into the side of the fitting you will make a noise :)
Step 4: Attaching to the pump
Step 5: It should now work
Step 6: Making it lower and louder
I added a second sink trap........