Is This A Correct Explanation

[Phebe]

Hi all,

Someone gave me this explanation as to how a cup phone works, and I wanted to reuse it, but I need to know if it's right because the stuff I found on google don't quite match it.

 

“The matchstick inside the speaker’s cup picks up the sound frequency and passes it to the other matchstick through the vibrations on the chord which links them, causing the reproduction of the sound in the listener’s cup, as vibrations of the same frequency pick up each other.”

 

He says it's sympathetic vibration, but when I look that up it sounds slightly different. Are they fundamentally the same thing, can I use that definition for how the cup phone works?

Thanks.

[Turtle]

Hi all,

Someone gave me this explanation as to how a cup phone works, and I wanted to reuse it, but I need to know if it's right because the stuff I found on google don't quite match it.

 

“The matchstick inside the speaker’s cup picks up the sound frequency and passes it to the other matchstick through the vibrations on the chord which links them, causing the reproduction of the sound in the listener’s cup, as vibrations of the same frequency pick up each other.”

 

He says it's sympathetic vibration, but when I look that up it sounds slightly different. Are they fundamentally the same thing, can I use that definition for how the cup phone works?

Thanks.

 

i'm not familiar with a cup-phone design using matchsticks. do you have a link to your source or a diagram?

 

anyway, sympathetic vibration is accurate though it often is mentioned in regard to restricted frequencies & their harmonics as in tuning forks or stringed instruments in auditory frequencies and in tuning radio signals in electronics. for the cup phone you want the restriction to be broad enough to encompass the frequencies of speech and it is the materials & their connections that determine this range.

 

here's a description that looks fitting to your purpose.

 

How Does a Paper Cup Phone Work

...

Speaking into the cup transmits the sound of the speaker's voice into the bottom of the cup. The bottom of the cup acts as a diaphragm and vibrates with the sound of the speaker's voice. As the bottom of the cup vibrates, it transmits the vibrations into the taut string. The sound travels along the string as a longitudinal wave and ultimately vibrates the bottom of the receiving cup. The cup transmits the sound into the air around the listener's ear, allowing her to hear the speaker. Because the sound travels through solid mediums--the cup and the string--it travels more effectively than through air, allowing the users to communicate across large distances with volumes that would be inaudible if spoken through air. ...

[Phebe]

Thank you Turtle, I don't have a diagram for it, but I saw one, it was basically the same setup except two matchstick anchored the string to the inside of the cups. The string would be tied to the sticks and they themselves lie flat across the bottom of the cups.

 

i'm not familiar with a cup-phone design using matchsticks. do you have a link to your source or a diagram?

 

anyway, sympathetic vibration is accurate though it often is mentioned in regard to restricted frequencies & their harmonics as in tuning forks or stringed instruments in auditory frequencies and in tuning radio signals in electronics. for the cup phone you want the restriction to be broad enough to encompass the frequencies of speech and it is the materials & their connections that determine this range.

 

here's a description that looks fitting to your purpose.

 

How Does a Paper Cup Phone Work

[Turtle]

Thank you Turtle, I don't have a diagram for it, but I saw one, it was basically the same setup except two matchstick anchored the string to the inside of the cups. The string would be tied to the sticks and they themselves lie flat across the bottom of the cups.

 

roger; i understand. :thumbs_up if a substitution is allowed, i'd use straight match-sized pieces of solid metal wire (pieces of clothes hanger) as it is denser than wood and will transfer the vibrations more effectively to the diaphragms. likewise, the stiffer/denser your string, the more effective the transmission. transmission of sound through physically connected dissimilar solids is what is happening, sympathetic vibration is how it is happening. :)

[Phebe]

roger; i understand. :thumbs_up if a substitution is allowed, i'd use straight match-sized pieces of solid metal wire (pieces of clothes hanger) as it is denser than wood and will transfer the vibrations more effectively to the diaphragms. likewise, the stiffer/denser your string, the more effective the transmission. transmission of sound through physically connected dissimilar solids is what is happening, sympathetic vibration is how it is happening. :)

 

I can dig that :D Thank you so much Turtle.