I need to find the frequency of a particular sound wave, what is the easiest way to go About this?

Question

Please note that this isn’t a school book physics problem where wavelength is readily available or anything, I’m trying to find the frequency of an actual sound wave produced when you circle your finger around the edge of a wine glass. Thanks!

Answer 1

My educated guess is 1 KHz

Answer 2

Download DA tuner lite, run it in a quiet environment and it will display the note of the vibrating glass. My small crystal glass vibrates at C7 - 18 hz . My cat loves this sound and leaps up to be near it

Answer 3

Take it to a piano and search for the nearest key. If you need a closer # go to a piano tuner or Music store. they have a frequency counter.

Answer 4

If you can borrow an audio spectrum analyser, it's easy. Even a Tektronix 492 will do it.

Answer 5

A guitar tuner type app is probably the simplest and easiest.



You can get them that display whatever note / frequency they "hear".



A few examples here:

https://www.theguitarjournal.com/the-9-best-guitar-tuner-apps/

Answer 6

You could always use a spectrometer, even an app for a smart phone.

Keep in mind, there are many variables that determine this frequency, glass diameter, thickness, and content of liquid in the glass, etc.

Answer 7

There are frequency meters available as cell phone apps. I'm using "Advanced Spectrum Analyzer Pro", but there are many others.

Answer 8

What equipment do you have? I have access to musical instruments.

So that I can play different notes until I find the one that matches the sound that I hear.

Then it is easy to calculate the frequency of the wave.



If you take middle C as 256 Hz or the A above middle C as 440 Hz then count the number of semitones to the frequency you are testing.

f = 2 ^ (n/12) * 440 ( for the semitones above A = 440 Hz)



Just note that unless your ear is good you can often be out by an octave ( or multiple octaves ). So using a keyboard with a pure tone ( flute ) makes it easier.



Unless you are unusual it is more likely that you can find a keyboard than a spectrum analyzer.

Answer 9

Record it, then play it back on an oscilloscope. Or a spectrum analyzer.



If you have a audio variable frequency generator, you can hook that to a speaker and adjust for a beat note. You can probably find this type of generator online somewhere and play it back through your computer.

Answer 10

If you model the wine glass as a cylinder that is closed on one end and open on the other, the length of the wine glass is a quarter wavelength for the fundamental frequency:

http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/clocol.html



Wavelength = Speed of Sound / Frequency, and speed of sound is approximately 340 m/s in typical room environments.



Helmholtz resonators are also pretty interesting: https://en.wikipedia.org/wiki/Helmholtz_resonance