Acoustics Management

Katie Barrett

Introduction The Acoustics Project is trying to reduce the amount of

sound pollution in the Murray Library on campus. The top

floor of the library was redesigned two years ago to a

more open study area with a cafe right in the middle.

With this redesign, a lot more sound was introduced into

the space. This sound travels from the cafe counter and

tables around it to the circulation desk and stacks. We

are working to mitigate the amount of sound pollution

that was a consequence of the redesign without blocking

the open floor concept.

Clients Our client is the Murray Library, located on the Messiah

College Campus. We are working to serve both the staff

of the library and the students who study there.

Further Information Further information on this project can be found at https://www.dropbox.com/home/

Infrastructure/Projects/Acoustics%20Project.

Results We have spent this year gaining a base of knowledge about acoustical design and

testing. Before this project, Messiah College Engineering had not done any project

involving acoustical testing. Our first phase involved a lot of research on what val-

ues and data we would test at once we started and how we would quantify sound

reduction.

After research, we started testing. For these tests, we talked to the library about

which areas they determined noisy and which areas were receiving a lot of sound.

The library deemed the stacks where students study and the desk of a librarian, Jo-

anna, as areas that received a lot of noise. We completed a lot of testing in the first

semester, but unfortunately with faulty data loggers. We completed our retesting in

January 2015. Our testing focused on determining the transmission of the library

space: if a sound was produced in one area, how much of it carried over into anoth-

er area.

The recommended decibel level for a library is between 30 dBa and 40 dBa. Ambi-

ent testing in the library found the average decibel level at Joanna’s desk to be 50

dBa and the stacks to be around 40 dBa. For comparison purposes, a decibel in-

crease of 10 dBa makes a noise sound twice as loud to the human ear.

Acknowledgements John Harro

Duane Troyer

Thien Nguyen

Dan Vivolo

Faculty Advisor: Dr. Brian Swartz

Professional Advisor: Mr. Bill Frantz,

Armstrong Industries

Mr. Todd Kister, Acoustical Testing Intertek

Mr. Eric Miller, Acoustical Testing Intertek

Results Since then, we have researched many different options for sound reduction, including sound

masking, sound blocking, sound paneling, transparent absorptive window covers, and local

sound absorption. After meeting with the library and researching plausibility, we determined

that our best option was sound paneling or plexiglass sound blocking.

Proposal Since we determined the most effec-

tive results, we have found multiple

companies that offer sound panels

that can also be artistic. This satis-

fies the aesthetic priority of the li-

brary. The pictures to the left are

tiles from Kirei Echopanel and Beax.

Location Decibel Output

Original Decibel Level at Receiver

Decibel Level at Receiver

After Noise

Transmission Producer Receiver

Cafe Joanna’s Desk 80 45 50 5

Lobby Joanna’s Desk 80 46 50 4

Circulation Desk

Joanna’s Desk 80 47.5 52 4.5

Cafe Back Wall of Stacks Area

80 36 37 1

Lobby Back Wall of Stacks Area

80 36 37.5 1.5

Cafe Stacks Front

Tables 80 37 37.5 0.5

Lobby Stacks Front

Tables 80 37 38.5 1.5

Transmission of Different Areas of the Library Paneling Locations Blocking Locations