Lesson 2: Wavelength & Pitch

Key Idea

Another critical property of a wave is its length. The wavelength is the physical distance between two identical points on repeating waves (usually measured from peak to peak). This distance determines the frequency of vibration, which humans perceive as pitch (how "high" or "low" a sound is).

Key Idea

There is an inverse relationship between wavelength and pitch.

• Short Wavelength: When waves are squeezed close together, they hit the receiver frequently. This creates a high pitch.
• Long Wavelength: When waves are spread out with a long distance between peaks, they arrive less frequently. This creates a low pitch.

By altering the wavelength, a source can produce the entire range of musical notes.

Key Idea

Simple sounds have constant pitch and volume, but complex communications involve changes. When a sound varies its pitch and volume over time, it creates a unique pattern.

In nature, animals use these distinct patterns (like a signature whistle) to identify individuals. This specific sequence of frequency modulation acts like an acoustic "fingerprint" or name.