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As the Sound Propagates
As-the-Sound-Propagates.mp3
As-the-Sound-Propagates.mp4
As-the-Sound-Propagates-Unplugged-Underground-XXVIII.mp3
As-the-Sound-Propagates-Unplugged-Underground-XXVIII.mp4
As-the-Sound-Propagates-intro.mp3
[Intro]
As the sound propagates
(My ear navigates)
As it did…
(Become one with solid)
[Bridge]
Once wed
(We could hear here)
[Refrain]
Less lost energy
(Less energy loss)
Amplifies
(Efficiencies)
As the sound propagates
(My ear navigates)
As it did…
(Become one with solid)
[Bridge]
Now wed (together, now in bed)
We can hear here
(Travelin’ through to you)
Put your ear to my chest
(Hear my heart beat the best)
[Refrain]
Less lost energy
(Less energy loss)
Amplifies
(Efficiencies)
As the sound propagates
(My ear navigates)
As it did…
(Become one with solid)
[Outro]
Faster
(Goes the speed of sound)
It’s found
(Faster)
Ear to ground
(It’s found)
More attention n’
(Less Attenuation)
ABOUT THE SCIENCE
Putting your ear against a solid medium like a wall (even with a glass) or railroad tracks “amplifies” sound because sound travels much more efficiently through dense solids than through air, reducing the amount of energy lost as the sound propagates.
The effect is due to two main physical principles:
1. Superior Transmission of Vibrations through Solids
Sound is a vibration or a pressure wave that requires a medium to travel.
* Molecules are closer together in solids: In solids like steel or glass, molecules are tightly packed and linked by strong intermolecular forces, allowing them to pass vibrational energy to their neighbors very quickly and efficiently.
* Faster speed of sound: Sound travels significantly faster in solids (e.g., about 5,100 meters per second in steel) than in air (about 343 m/s). This rapid transmission means less energy is lost along the way compared to the sound wave dissipating in all directions through the less dense air.
* Energy Conservation (Less Attenuation): The sound wave’s energy stays contained and focused within the solid medium (like the linear path of a rail), rather than spreading out spherically in three dimensions as it does in the open air, where intensity drops quickly due to the inverse square law.
2. Overcoming “Acoustic Impedance Mismatch”
Acoustic impedance is a measure of how much a medium resists the flow of sound energy. When sound travels from one medium to another with a very different impedance (like from air into a solid wall and back to air), most of the energy is reflected away at the boundary.
* Direct Coupling: By placing your ear (which is mostly fluid and tissue, a higher-impedance medium) directly onto the glass or track, you create a direct acoustic coupling with the solid material.
* Bypassing the Air Interface: You bypass the poor air-to-solid and solid-to-air energy transfer points. The vibrations are transmitted directly into the material of your head and inner ear via bone conduction, which is more efficient than relying on the very weak vibration of the tiny amount of air next to the wall.
The Role of the Glass
The glass acts as a solid extension of the wall, providing a rigid object that can form a better seal against the ear than the curved surface of the head could form with the flat wall, making the effect more practical.
From the album “Amplification“
View all episodes
By As-the-Sound-Propagates.mp3
As-the-Sound-Propagates.mp4
As-the-Sound-Propagates-Unplugged-Underground-XXVIII.mp3
As-the-Sound-Propagates-Unplugged-Underground-XXVIII.mp4
As-the-Sound-Propagates-intro.mp3
[Intro]
As the sound propagates
(My ear navigates)
As it did…
(Become one with solid)
[Bridge]
Once wed
(We could hear here)
[Refrain]
Less lost energy
(Less energy loss)
Amplifies
(Efficiencies)
As the sound propagates
(My ear navigates)
As it did…
(Become one with solid)
[Bridge]
Now wed (together, now in bed)
We can hear here
(Travelin’ through to you)
Put your ear to my chest
(Hear my heart beat the best)
[Refrain]
Less lost energy
(Less energy loss)
Amplifies
(Efficiencies)
As the sound propagates
(My ear navigates)
As it did…
(Become one with solid)
[Outro]
Faster
(Goes the speed of sound)
It’s found
(Faster)
Ear to ground
(It’s found)
More attention n’
(Less Attenuation)
ABOUT THE SCIENCE
Putting your ear against a solid medium like a wall (even with a glass) or railroad tracks “amplifies” sound because sound travels much more efficiently through dense solids than through air, reducing the amount of energy lost as the sound propagates.
The effect is due to two main physical principles:
1. Superior Transmission of Vibrations through Solids
Sound is a vibration or a pressure wave that requires a medium to travel.
* Molecules are closer together in solids: In solids like steel or glass, molecules are tightly packed and linked by strong intermolecular forces, allowing them to pass vibrational energy to their neighbors very quickly and efficiently.
* Faster speed of sound: Sound travels significantly faster in solids (e.g., about 5,100 meters per second in steel) than in air (about 343 m/s). This rapid transmission means less energy is lost along the way compared to the sound wave dissipating in all directions through the less dense air.
* Energy Conservation (Less Attenuation): The sound wave’s energy stays contained and focused within the solid medium (like the linear path of a rail), rather than spreading out spherically in three dimensions as it does in the open air, where intensity drops quickly due to the inverse square law.
2. Overcoming “Acoustic Impedance Mismatch”
Acoustic impedance is a measure of how much a medium resists the flow of sound energy. When sound travels from one medium to another with a very different impedance (like from air into a solid wall and back to air), most of the energy is reflected away at the boundary.
* Direct Coupling: By placing your ear (which is mostly fluid and tissue, a higher-impedance medium) directly onto the glass or track, you create a direct acoustic coupling with the solid material.
* Bypassing the Air Interface: You bypass the poor air-to-solid and solid-to-air energy transfer points. The vibrations are transmitted directly into the material of your head and inner ear via bone conduction, which is more efficient than relying on the very weak vibration of the tiny amount of air next to the wall.
The Role of the Glass
The glass acts as a solid extension of the wall, providing a rigid object that can form a better seal against the ear than the curved surface of the head could form with the flat wall, making the effect more practical.
From the album “Amplification“