4 ms·
What is it about that sound (https://upload.wikimedia.org/wikipedia/commons/1/1d/Emergency_Alert_System_Attention_Signal_20s.ogg https://upload.wikimedia.org/wi
by supermatt 4y ago
What is it about that sound (https://upload.wikimedia.org/wikipedia/commons/1/1d/Emergency_Alert_System_Attention_Signal_20s.ogg https://upload.wikimedia.org/wikipedia/commons/1/1d/Emergenc...) that causes it to make my ear drums to vibrate?
Is there some "formulae" for mixing frequencies that perform similar effects? I recall reading something a few years ago (it was likely posted here) about discordant tones.
- 3pac 4y agoIt's called a beat. The very greatest musicians have struggled with it. Try going to a piano, and playing two notes, black or white, that are immediately next to each other at the same time (a half-step interval). Further listening: Modest Mussorgsky's The Hut of the Baba Yaga, and Miles Davis' Someday My Prince Will Come.
- an_aparallel 4y agoi'm not able to explain this as well as a physics major: these are called "tartini beats"/"combination tones" etc: https://en.wikipedia.org/wiki/Combination_tone https://en.wikipedia.org/wiki/Combination_tone They are actually always occurring (if the notes as sufficiently dissonant) - so the calculations are nothing more than subtraction ie. 440 - 215 = 5hz some combination tones are louder than others usually as there is less phase cancellations occurring.
- jacquesm 4y ago440 - 215 = 5? I think you got the principle right but used the wrong A for your example (you used A4, probably meant to use A3)? 440 and 215 would interact as 440 and 430 (an octave above the 215) so you'd get a difference of 10 Hz, not 5. (And the sums as well, of course.)
- an_aparallel 4y agoi did something wrong...and i didnt even get my equals sign right :) Thanks for the correction!