To analyze sound, a subset of artificial intelligence known as a neural network needs a visual representation of a sound wave called a spectrogram. The graphic above is a spectrogram of two elephants communicating through low-frequency rumbles. The white line is the upper boundary of infrasound, about 20 hertz, below which humans can’t hear.

To analyze sound, a subset of artificial intelligence known as a neural network needs a visual representation of a sound wave called a spectrogram. The graphic above is a spectrogram of two elephants communicating through low-frequency rumbles. The white line is the upper boundary of infrasound, about 20 hertz, below which humans can’t hear.