Acoustic Basics: Sound Waves Explained

Sound waves begin with a vibrating source, such as a guitar string.These vibrations create compressions and rarefactions in the surrounding air molecules.Sound waves can travel through various media, including air, water, and solid materials.Unlike light waves, sound waves cannot travel through a vacuum, as they require a medium to propagate.Sound waves propagate outward in all directions from their source, similar to ripples in a pond.Sound waves have three main properties that shape what we hear: frequency, amplitude, and wavelength.Let's start with frequency, measured in Hertz. A low frequency of 440 Hertz creates a lower pitch, like this A note.When we double the frequency to 880 Hertz, we get a higher pitch - exactly one octave higher.Next is amplitude, which determines how loud a sound is. This soft sound has a small amplitude.When we increase the amplitude, the sound becomes louder, while keeping the same pitch.Finally, let's examine wavelength - the distance between wave peaks. Here's one complete wavelength.Wavelength and frequency are inversely related. As frequency increases, wavelength decreases, and vice versa.When sound waves reach our ears, they travel through the ear canal to the eardrum.The waves cause the eardrum to vibrate back and forth.These vibrations are amplified by three tiny bones in the middle ear: the malleus, incus, and stapes.The vibrations then reach the cochlea, a spiral-shaped organ filled with thousands of tiny hair cells.Humans can typically hear frequencies between 20 Hertz and 20,000 Hertz.Different animals have evolved to hear different frequency ranges. For example, dogs can hear up to 67,000 Hertz, while bats can detect frequencies above 100,000 Hertz.Let's review what we've learned about how we perceive sound.Thanks for learning about sound perception with Spark.E!