Sound Wave Basics: An Introduction to Types and Measurement

Sound is a form of energy we experience through our ears. It travels as vibrations through a medium, be it air, water, or solids. Without a medium, sound waves simply can’t propagate. In dry air, sound travels at approximately 332 meters per second, while in water, it speeds up to around 1450 meters per second. Human speech and musical instruments typically produce sound waves ranging from 30 Hz to 12 KHz. Sound can be stored and reproduced later using various technologies.

Types of Sound Waves

There are three primary types of sound waves, categorized by their frequency:

• Infrasonic Waves: These are sound waves with frequencies below 20 Hz. Humans can’t typically hear them.
• Ultrasonic Waves: These waves have frequencies above 20 KHz, beyond the range of human hearing. They have many applications, including communication, measuring sea depth, and even improving agriculture.
• Audible Waves: These are the sound waves we can hear, ranging from 20 Hz to 20 KHz. This range can vary from person to person, especially with age.

Hi-Fi and Hi-Qu Sound

Let’s delve into the world of high-quality audio:

• Hi-Fi Sound: “Hi-Fi” stands for High Fidelity. It refers to sound reproduced by a loudspeaker or headphones that accurately contains all the fundamental and harmonic frequencies present in the original input signal. Essentially, it’s a faithful reproduction of the sound.
• Hi-Qu Sound: “Hi-Qu” means High Quality. This describes sound from a loudspeaker or headphones that is free from distortion. It’s a clean, pure sound.

Measuring Sound: Decibels

The intensity of a sound wave relative to another is measured using a logarithmic unit called the decibel (dB). The formula is:

dB = 10 * Log (P2/P1)

Where:

• P1 = intensity of one sound
• P2 = intensity of another sound

Converting Sound to Electrical Signals

Microphones convert sound waves into electrical signals, which can then be digitized. For more details, refer to resources about microphone basics.