Put simply, sound is vibration. As such, sound can pass through many different substances - in fact, it requires the presence of a medium. Sound cannot travel in a vacuum.

Pod Complex

The frequency of a wave refers to how often the particles of the medium vibrate when a wave passes through the medium. The frequency of a wave is measured as the number of complete back-and-forth vibrations of a particle of the medium per unit of time.

The Physics Classroom

Pitch is a description of the frequency of the sound. Different pitches correspond to different frequencies. High pitch means high frequency, and low pitch means low frequency.

Pitch can also be described as the quality of a sound that allows you to label it as “higher” or “lower” to your ear. Someone with perfect pitch has an ear so attuned that they can identify a note exactly by hearing it. Especially talented individuals can even play an entire piece of music after hearing it once.

Sciencing

A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism.