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Sound
Hraness wrote this summary from a saved copy of the source. Quotations are taken word for word from the source.
gist
Bartosz Ciechanowski's interactive essay explains what sound is by building it up from the collisions of individual air molecules. Moving plates, sine-wave tones, masses on springs, and pulsing spheres show how vibrations become pressure waves that spread, reflect as echo and reverb, and reach our ears as everything from noise to music. The playable demos are not captured here.
ideas
- Sound is air collisions. Air pressure comes from countless fast molecules hitting surfaces; sound is a small, traveling change in the number and intensity of those collisions.
- Motion makes the disturbance. A sudden jump of a plate makes a pop whose loudness grows with the jump; steady vibration makes a sustained tone.
- Tones have three knobs. Amplitude, frequency, and phase map onto a rotating circle, and human hearing covers only a band of frequencies at uneven loudness.
- Springs explain vibration. Masses on springs oscillate at natural frequencies set by mass and stiffness, a model for how objects ring.
- Waves spread and bounce. Pulsing spheres radiate pressure waves; walls reflect them as echoes, which merge with the original under about 50 ms, and rooms sustain them as reverb.
quotes
“Invisible and relentless, sound is seemingly just there, traveling through our surroundings to carry beautiful music or annoying noises.”
“when it’s smaller than around 50 ms, our auditory system doesn’t discern these two separate sounds.”
“I find it fascinating that the most irritating noises and the most inspiring music are driven by the same phenomena”