What is the difference between frequency, resonant frequency, natural frequency, and fundamental frequency?
Fundamental frequency is the correct name given to the repetition frequency of a complex periodic waveform, i.e. how many cycles of the waveform occur in one second. Resonant frequency, or natural frequency, is the name given to the frequency which is ‘most preferred’ by a simple resonator, i.e. the frequency which it most likes to vibrate at, or equivalently, the stimulating frequency which gives the biggest response. Otherwise, we should only use the term ‘frequency’ to describe simple periodic waveforms: i.e. sinewaves. This is why we can say that the fundamental frequency of a vowel is X Hz, but not that the frequency of a vowel is X Hz, because vowels are not simple periodic waveforms.
