I just can’t wrap my head around it. Is it just crazy brain things, a difference in number of waves, or some other thing? How is it possible that a speaker can replicate all sounds?
In: 24
In short, overtones. It’s not just one sound at one pitch, but a blend of many higher pitches.
A pure tone is a sine wave. That’s generated with an electronic device. It’s the top wave in this [graph](https://en.wikipedia.org/wiki/Square_wave#/media/File:Waveforms.svg). You can create waves of different shapes by adding a bunch of different sine waves on top of each other.
On that graph, the y-axis is pressure and the x is distance (or time since the waves travel). By taking a bunch of different sine waves with a wavelength of 1/2, 1/3, 1/4, (and so on) of the first, they can be added together to get a wave that’s shaped differently but has the same frequency. Here’s a [gif](https://en.wikipedia.org/wiki/Square_wave#/media/File:Fourier_series_for_square_wave.gif) of a square wave being made by adding together a bunch of sine waves.
By precisely choosing the amplitudes and phases of each wave, waves of any shape can be generated. Waves with different shapes at the same frequency will sound different even though the pitch is sounds the same.
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