When we hear, our ear canals take in vibrations from the surrounding environment and translate them into nerve impulses that travel to our brain, where they are pro­cessed as audible sounds. Sounds are created when an object that vibrates, like a guitar string being plucked, causes pressure pulses of air molecules that vibrate, called sound waves. The ear detects and analyzes many physical properties of the waves to differentiate between subjective features of a sound, such as its volume and pitch. The perceived frequency of sound waves, or pitch, is the number of wave­lengths passing a xed place in one unit of time. The unit of measurement for fre­quency is hertz, which stands for cycles per second. While the human ear is most acute and capable of picking up sounds in the 1000–4000Hz range, the full spec­trum of audible sounds spans roughly 20–20,000Hz, at least for typically develop­ing juvenile ears. While other mammals can hear them, sound waves with an even higher frequency are called ultrasonic. The sense of the strength of sound, or the pressure that sound waves impose on the tympanic membrane, is what we mean when we talk about loudness. A sound’s force, intensity, and, by extension, volume are all proportional to its amplitude or strength. One way to convey the relative amplitude of a sound on a logarithmic scale is via its measurement in decibels (dB), commonly used to report sound intensity. Decibels are a measure of good intensity relative to one another and a reference sound audible to the average person at a fre­quency within the audible range. A human ear can detect sounds at around 130dB, the threshold at which they start to feel discomfort, and at 0 dB, the threshold at which they are nearly inaudible [10].