Resonators are used to either generate waves
of specific frequencies or to select specific frequencies from a signal. Musical instruments use acoustic resonators that produce sound waves of specific tones. A sound wave has the same characteristics as any other type of waveform: wave-
length, frequency, and amplitude. The wavelength is the distance from one crest
to another of a wave. The frequency of sound is the rate at which the waves pass
a given point, i.e. it is the number of oscillations (cycles) that occur each second
of time. The amplitude, is the peak deviation of the function from zero. The
simplest representation of a sound wave at a fixed point of the space is given by
the sine wave, that is a sinusoid. Its most basic form as a function of time t