A resonator is a screen that lets some frequencies of a complex tone through while inhibiting others.
There was a case of a large suspension bridge in Washington State (the Tacoma Narrows Bridge) which in 1940 was whipped so vehemently by wind gusts which matched the natural frequency of the bridge that it collapsed. You can see this in the notes below.
The point is that frequencies that match the natural frequency of a resonator are facilitated whereas those that do not match are inhibited.
Hence, the resonator acts as a screen which can eliminate some frequencies in a complex tone while facilitating others.
This is the function of the modulators, which we will discuss soon as part of the Expressive Transducer for the Aural Modality (e.g., the mechanism of speech). We will discuss how they change the pattern of overtones produced by the larynx to create the vowel sounds of speech.
NOTES: See the Tacoma Bridge Collapse
NOTES: More on the Tacoma Bridge
NOTES: One last word on the Tacoma Bridge Collapse.