1. Absorption Comparison
What’s That Sound?: A Comparison of Sound Absorption of Different Commercial Flooring
Introduction
Results
Noise levels in city restaurants are regularly measures at 90 decibels and sometimes higher, which means for us customers hearing loss is an officially an occupational hazard. The health of people is being affected in trumornous ways. Business owners tend to find sound a healthy factor in the progress of their business but now more than ever sound production in restaurants is becoming more of a hazard rather than an asset. The reason being that business owners don't take into consideration sound absorbance when finding the right commercial flooring.
The absorption coefficient is the measurement used for the sound waves that determines how far into a material light of a particular wavelength can penetrate before it is absorbed. With that said a low absorption coefficient means sound is transmitted back at high levels while a high coefficient allows for sound to diminish. Carpet at 125 Hz frequency had a measurement of .02 and at 2000 hz has a measurement of .6. Wood at 125 Hz frequency had a measurement of .15 and at 2000 Hz has a measurment .06. Vinyl at 125 Hz frequency had a measurement of .013 and at 2000 Hz has a measurment .04. Wood at 125 Hz frequency had a measurement of .02 and at 2000 Hz has a measurment .02.
Problem
Of the variables that are to be tested, carpet will be the one to have the greater absorption due to its characteristics of not being solidified by its padding, softness, and flexibility.
Hypothesis
Which material has the most substantial absorption when exposed to various sound variations?
Materials
Variables
Control variables- The decibels and sound source
Independent variables- the different flooring materials
Dependent variables- frequency and absorption coefficient
Trial 1
Model of the two microphone method.
Absorption Comparison
Carpet
Rubber Flooring
Vinyl Flooring
Wood flooring
Tape
2 microphones
Rigid Plunger
Speaker (50 to 100 watts)
Back Plate
Brass Tube 4"(diameter) x 3' (length)
At 125 Hz Carpet ≥ Rubber > Wood > Vinyl
At 250 Hz Wood > Carpet > Rubber > Vinyl
At 500 Hz Carpet > Wood > Rubber > Vinyl
At 1000 Hz Carpet > Wood > Vinyl ≥ Rubber
At 2000 Hz Carpet > Wood > Vinyl > Rubber
Trial 3
Trial 2
Conclusion
After running various tests on a constant environment, my hypothesis of the carpet being the most adequate compared to the other materials, was proven correct. Although carpet and rubber exhibited about the same measurements at the lowest level tested, carpet conveyed the most substantial growth as the level of frequency was increased. Both vinyl and rubber did not meet the levels of absorption as efficiently as carpet. I deciphered the different materials used in commercial flooring with the accomplished goal of drawing the conclusion that carpet is the best material when looking for the greatest sound absorption.
Procedures
Table of Coefficients of Absorption for trial 2.
Table of Coefficients of Absorption for trial 3.
Table of Coefficients of Absorption for trial 1.
Trial 2
Trial 3
Cut the tube in two pieces, 2’ and 1’ respectively. (The 2’ will be used as the long tube and the 1’ will be for mounting of samples.)
Create two holes ½ an inch apart on the longer tube for the mounting of the microphones.
Mount the microphones and make sure they are flush with the inside wall of the tube and isolated from the tube (to minimize sensitivity to vibration)
In the 1’ tube, put the backplate on the rear to secure the plunger.
Adjust the material adequately to fit in the tube firmly and securely, but make sure you are able to take it out easily without disrupting the system.
Record the sound for about seconds with the desired sounds.
Using WavePad, analyze the frequencies and record for further comparison.
Repeat steps 5-7 with every material
Trial 1
Applications
Table of percentage of absorption coefficients for trial 3.
Table of percentage of absorption coefficients for trial 1.
Table of percentage of absorption coefficients for trial 2.
Finding the best commercial flooring type for your business is crucial. Whether it be carpet or wood flooring. Different factors need to be considered including sound absoprtion and customer population. By seeing the sound absorption of different materials business owners can make the best decision for their businesses. Creating better healthier enviroments for us customers.
Bibiography
Absorption Coefficient. (n.d.). Retrieved January 7, 2016, from
Communications System. (n.d.). Retrieved January 7, 2016, from
(n.d.). Retrieved January 7, 2016, from Platt: Why Restaurants Are Louder Than Ever. (2013, July 13). Retrieved January 6, 2016, from Tips for Choosing the Best Commercial Flooring Type for Your Business - Flooring Solutions Inc. (2013, June 20). Retrieved January 6, 2016, from commercial-flooring-type-for-your-business/
Seybert, A. (n.d.). Notes on Absorption and Impedance Measurements. Retrieved from
Measurement of the sound absorption coefficient of materials with a new sound intensity technique. (n.d.). Retrieved from
Bar graph depicting different absorption Coefficients at different frequencies for trial 3.
Bar graph depicting different absorption Coefficients at different frequencies for trial 1.
Bar graph depicting different absorption Coefficients at different frequencies for trial 2.
Line graph depicting different absorption Coefficients at different frequencies for trial 1.
Line graph depicting different absorption Coefficients at different frequencies for trial 2.
Line graph depicting different absorption Coefficients at different frequencies for trial 3.
Researcher cutting vinyl flooring
Researcher getting measurements
Researcher cutting tube into 2’ and 1’.
Researcher drilling ½ inch apart holes in the longer tube.
Images gathered from Resonance - Google Search. (n.d.). Retrieved January 22, 2016, from
Images gathered from Measurement of the sound absorption coefficient of materials with a new sound intensity technique. (n.d.). Retrieved from
All Photos taken by researcher
Images gathered from Seybert, A. (n.d.). Notes on Absorption and Impedance Measurements. Retrieved from
Tables & Graphs were created by Microsoft Word Excel.