I received a question about the noise made when the weights at the end of each prong of a weighted tuning fork touch. If the weights are touching when you tap then you are tapping too hard.
I usually recommend tapping the weight of the fork against the heal of you palm, pinkie side (see this video). I prefer this because it is quiet. If you are working with others then you want to maintain a quiet environment and aluminum against a hard surface will disturb that quiet environment. I also understand that tapping against your palm may be uncomfortable for some. In that case I recommend using an activator (hockey puck). If you can, put it in your pants pocket and tap the fork against that to muffle the sound.
Tap Lightly First
Most people start by tapping very hard thinking that this is what it takes to get a good tone. A weighted tuning fork will ring between 8-15 seconds depending on the frequency. Whether you are using your palm or puck, tap lightly first. If the tone stops after a few seconds then try again tapping a little harder. Keep doing this till you understand how hard to tap the fork. Work your way up to a strong tone.
Please Do Not Use a Mallet
There are several manufacturers offering mallets with their forks. Please do not use these. Doing so puts you in the habit of using one fork at a time. The power of sound healing with tuning forks is using several forks at once to create harmonics (this is mainly for unweighted forks). Also, the mallets you'll see online are too light weight to create a solid tone.
If you see a manufacturer providing an Allen wrench with their weighted forks to tighten the weights, avoid them. The weight of a tuning fork should never come loose.