Eli5: Why can different singers sing the same song with the same notes but still sounds different?


I understand notes as the wavelength one tone hits. Then if very skilled singers would sing the same song and hit every note right. Why does it still sounds like different people? Our ears just hear the soundwaves right?

In: 1

Sound waves aren’t individual notes, they are a combination of different notes known as [timbre](https://en.wikipedia.org/wiki/Timbre). Different singers as well as different instruments have different timbres.

By that same logic every instrument of every type should sound the same, and you shouldn’t be able to tell a singer from a piano.

Notes only have pitch and duration, pitch is how high or low the sound is, and as long as the sound is hitting that pitch then it’s doing the right note.

But we don’t produce perfect square sound waves, every sound has to ramp up to the desired pitch, stay there and then come down. The irregularities (small ups and downs) on the sound as it does that are called timbre and are what allows us to distinguish different sounds, even if they have the same pitch.

You obviously know every person is different, so it follows that their throats will be different and so will their timbre.

Voices have different timbres or tone colors, because the vocal chords that produce the sounds are different sizes and shapes in different people , and also because we can use different vocal techniques to vary our timbre to some extent. Humans have evolved to perceive timbre very well—we recognize voices we know, even over the phone or in a recording. This is probably because recognizing the source of an unseen sound is sometimes helpful for survival

Same reason a guitar and a banjo sound different – the space in which the sound is developed is different and the hole it comes out of is different. Plus, singers also change the shape of their instrument and their hole as they sing.

Well, it’s really not too different from the same singer singing a single note and changing what vowel they are singing.

When we think of the note that someone is singing or an instrument is playing, we’re really talking about the*fundamental* note. When something produces a note, it actually produces a series of notes, getting higher and higher. But, because these notes are really closely related (something called the *harmonic series*) they blend together. Instead of hearing them as a bunch of notes, we hear them as a single note with a particular tone, colour, or *timbre*. Changing the relative loudness of all these *overtones* changes the timbre. This is what lets us hear the difference between different singers, as well as between different instruments. It’s also what’s responsible for vowels.

Try this: download a spectrum analyser app (frequensee used to be a good free one. Don’t know if it still is). Then sing the letter “Aaaaaah”. You’ll see a big spike at the pitch you’re singing, and then a bunch of other spikes at higher frequencies. If you change the note you’re singing, you’ll see all the spikes moving one way or the other together. Now try again, but this time sing “Aaaaaaaaaaeeeeeee,” changing sound part way through. You’ll see that the big spike stays the same, but all the other spikes get bigger or smaller.

Each person has a slightly different way of blending those overtones together, so the extra spikes would be slightly different. That’s why it sounds different to us even though the fundamental note is the same.