Before you learn about audio hardware, recording, editing and mixing and all that technical jargon, you must first have an understanding of the fundamentals of audio. Once you understand these basic concepts, we will be able to explain how they relate to what you are doing, and apply them through your real world experience!

Every sound consists of rapid variations in air pressure (or any other medium that conducts sound). Anything that makes sound; guitar strings, drum heads, vocal chords, etc. does so by vibrating back and forth. Vibrating surfaces push air molecules back and forth, creating positive and negative changes in air pressure. These changes in air pressure are called sound waves. These waves travel through space via the compression and rarefaction of air molecules and upon reaching our ears the waves are introduced to our aural receptors as vibrations. The brain then interprets these signals as sound.

There are 3 basic aspects to the wave that we can see from the diagram :

Frequency - Pitch is determined by the frequency of the sound, or the number of cycles per second measured in Hertz (Hz). One cycle is made up of both the positive and negative part of the wave. The more frequent the cycles/faster the vibration, the higher the pitch; the less frequent the cycles/slower the vibration, the lower the pitch. In general, we can hear a frequency range from 20 to 20,000 Hz.

Amplitude - Volume is determined by the height of the wave, or amplitude typically measured by ratios in decibels (dB). The higher the amplitude, the louder the sound; the lower the amplitude, the quieter the sound. There are different types of decibels, each with its ratio based on a different reference. In most sequencing software, the unity gain is 0.0 dB, or the point at which the original signal is neither amplified or attenuated.

Timbre - The shape of the wave determines the Timbre or quality of the sound. This is what makes a flute sound different than a trombone even if they are playing with the same amplitude and frequency.

Microphones and instrument pickups typically act as the ears of our audio recording system, converting sound waves into an electrical signal. This electrical signal can then be amplified, recorded and even modified using various audio equipment. Speakers act as the sound source of our recording system, converting an electrical signal into sound waves.