A more thorough explanation:

Definition: A machine that analyzes sound, like a person's voice, by breaking it down into different parts based on frequency, time, and intensity. It creates a visual representation of these parts in the form of horizontal and vertical lines, called a voiceprint.

Example: A spectrograph is often used in criminal investigations to analyze recordings of a suspect's voice. By comparing the voiceprint of the suspect to the voiceprint of a recorded voice at the crime scene, investigators can determine if the suspect was present.

Explanation: The example illustrates how a spectrograph can be used to analyze a person's voice and create a unique voiceprint. By comparing voiceprints, investigators can determine if a suspect's voice matches a recorded voice at a crime scene, which can be used as evidence in a criminal trial.