06-07-2021, 02:23 AM
Noise reduction is the complex and important matter.
I was trying to find an App to simply measure efficiency of noise reduction approaches.
A lot confusing info can be found on the web in the regard.
The main problem is the difference in reaction of different media to either absorb or reflect the sound
at different frequencies. Lightweight porous materials might be good absorbers at high frequencies, but hardly
make any barrier for lower frequencies.
The idea of an experiment is simple.
1. Two phones are placed one by another. The first generate the sinusoidal signal at different frequencies,
while the second one is recording the signal strength. The sender set its loudspeaker at 100% max level
for a given frequency. The receiver is recording signal at each frequency. Both are communicating per wifi or
bluetooth.
2. Then they go apart. For example at 2 sides of a door or a window or a wall. The same procedure
is repeated. Then by calculation the absorption spectra is plotted at the receiver phone.
N.B. One can reverse the roles and check if the sound goes as well in both direction or not.
3. The real experiment begins when the door is made fully closed or slightly open. The edge of the door is
sealed or remains as is. The same can be repeated with a window or a wall and various soundproofing materials.
The sender and/or receiver phone can be placed in the air or tightly connected to the barrier material.
The results won't be 100% precise, but would give an idea what material works best and how the procedure may influence
the results. It can also teach users, that protecting from lower frequencies is much harder, than higher ones.
Your phyphox App need just a small upgrade to add that feature.
Thx
P.S. If one knows where such an App is already available, pls let me know.
I was trying to find an App to simply measure efficiency of noise reduction approaches.
A lot confusing info can be found on the web in the regard.
The main problem is the difference in reaction of different media to either absorb or reflect the sound
at different frequencies. Lightweight porous materials might be good absorbers at high frequencies, but hardly
make any barrier for lower frequencies.
The idea of an experiment is simple.
1. Two phones are placed one by another. The first generate the sinusoidal signal at different frequencies,
while the second one is recording the signal strength. The sender set its loudspeaker at 100% max level
for a given frequency. The receiver is recording signal at each frequency. Both are communicating per wifi or
bluetooth.
2. Then they go apart. For example at 2 sides of a door or a window or a wall. The same procedure
is repeated. Then by calculation the absorption spectra is plotted at the receiver phone.
N.B. One can reverse the roles and check if the sound goes as well in both direction or not.
3. The real experiment begins when the door is made fully closed or slightly open. The edge of the door is
sealed or remains as is. The same can be repeated with a window or a wall and various soundproofing materials.
The sender and/or receiver phone can be placed in the air or tightly connected to the barrier material.
The results won't be 100% precise, but would give an idea what material works best and how the procedure may influence
the results. It can also teach users, that protecting from lower frequencies is much harder, than higher ones.
Your phyphox App need just a small upgrade to add that feature.
Thx
P.S. If one knows where such an App is already available, pls let me know.