Audio Bit Depth Sample Size and Sampling Rate

1. Sound moves through what medium?

Sound travels in mechanical waves. A mechanical wave is a disturbance that moves and transports energy from one place to another through a medium that can be solid liquid or gas. In sound, the disturbance is a vibrating object. And the medium can be any series of interconnected and interactive particles. This means that sound can travel through gases, liquids and solids.

Let's take a look at an example. Imagine a church bell. When a bell rings, it vibrates, which means the bell itself flexes inward and outward very rapidly. As the bell moves outward, it pushes against particles of air. Those air particles then push against other adjacent air particles, and so on. As the bell flexes inward, it pulls against the adjacent air particles, and they, in turn, pull against other air particles. This push and pull pattern is a sound wave. The vibrating bell is the original disturbance, and the air particles are the medium.

2. What unit is used to measure sample size?

Essentially this is the number of digits in the digital representation of each sample. Think of the sample rate as the horizontal precision of the digital waveform, and the sample format as the vertical precision which is measured usinh Hz


3.  What unit is used to measure sampling rate?
The rate at which the samples are captured or played back, measured in Hertz (Hz), or samples per second. 


4.  Compare the quality of AM, FM and Digital radio.
AM radio ranges from 535 to 1705kHz
FM radio band goes from 88 to 108 MHz
Digital radio has frequencies below 30MHz