In ENT, tuning forks are used to clinically test hearing and identify the type of hearing loss.
The parts of a tuning fork are:
- Base plate or footplate
- Prongs that vibrate producing sound
If you look at the shaft or the footplate closely, you will find it carries a number - this is the frequency at which the tuning fork vibrates and is denoted in Hertz (Hz). The commonly used tuning forks to test hearing are 256 Hz, 512 Hz and 1024 Hz. These frequencies correspond to the speech frequencies.
Tuning forks of lower frequencies (like 128 Hz) produce vibrations that are felt more than they are heard, while those of higher frequencies produce more overtones.
Prerequisites for an ideal tuning fork:
- It should be made of a good alloy
- Its build should be sturdy
- It should vibrate at the specific frequency
- It should maintain its vibrations for one full minute
- It should not produce overtones