The spectrogram is a graphical representation of a sound wave, a visual approach to seeing sound. Play the video, and as the cursor moves across time from left to right, frequencies that make the sound wave can be seen, with the low frequencies on the bottom and the high frequencies higher up. As the sound gets louder, the pixels get brighter; inversely the darker pixels represent the quieter sound – or where the pixels are black no sound at all. Notice the coyote’s first call at around six seconds, the lowest frequency is called the fundamental frequency – about 1000 hertz for this coyote’s first note. The frequencies directly above that first note are called harmonic frequencies. They are multiples of the fundamental frequency and create the unique sound of the coyote’s voice, which we also call timbre. The sounds combine in a unique way to make the coyote sound like a coyote.
Fred Bell 