how can lots of different sounds like a band be recorded onto a single sound wave? Or is it actually lots of different sound waves and then “generalized” into one wave?

Question

I understand how a single sound wave works, but I’m picturing the track on a vinyl record. How is a needle riding a single soundwave playing back all of those uniquely different sounds?

In: 4

Answer 1

Sound waves simply describe the motion of air molecules at acoustic frequencies. Lower frequencies make the molecules wiggle slower. Higher frequencies make them wiggle faster.

Hold a laser pointer in your hand. As you draw the dot from left to right across the wall in front of you, large slow arm movements yield a nice sine wave with maybe two or three peaks before you run out of wall. Now, imagine the laser pointer is taped to one of those old electric razors that buzzed like crazy and made your hands tingle if you held it too long.

Repeating the same manoeuvre, sweep the draw the dot across the wall, lifting waving your arm up and down while holding the “lazor.” The dot follows a similar path as before, with the exception that the razor’s higher frequency vibration is recorded as well. The dot merely represents how a the motion of single object may be seamlessly influenced by multiple sources, which superimpose their influences simultaneously and harmoniously onto the same object.

So it is with air molecules and whatever adds energy to their motion.