Why does a tuning fork's fundamental frequency differ from its stamped frequency?

[Gareth]

I'm writing up project on tuning forks and came across website:

http://www.wrps.net/~dave_bergerson/labs/WaveSoundLight/Tones.doc

which suggests that a tuning fork has a fundamental frequency that is different from the frequency stamped on the fork, due to some corrections due to its overtone frequencies. I'm not sure of the origin of this discrepency, is it due to sound interfearing or the way the brain interprets the noise? Has anyone got any equations to qualitativly predict what is going on?

Thanks in advance for your suggestions

 

[chroot]

which suggests that a tuning fork has a fundamental frequency that is different from the frequency stamped on the fork, due to some corrections due to its overtone frequencies.

I don't believe the document says that at all. What it says is that any tuning fork will vibrate at its fundamental frequency (the one stamped on it), and also at multiples of that frequency. These multiples are called harmonics.

Generally, the fundamental-mode vibration is the largest amplitude, and thus the most easily heard. If you strike a tuning fork and then touch it in the right place to dampen the fundamental vibration while permitting one or more harmonic vibrations, you can then hear the harmonics.

- Warren