Case Study: The Chapman Graduate School of Business

Nicole Figueroa/ Kamilah Bermudez/Elizabeth BerrymanAcoustics Assignment #5

Sections:

Acoustic wall panel: Used as sound absorbent treatment to control reverberation, echo, and flutter

Cushioned Auditorium Seating: Open-weave fabric, backed with sound absorbent material. (Binggeli, Pp. 388)

Acoustic ceiling tiles: Designed to improve sound quality

and block noise transmission.(Binggeli, Pp. 392- 393)

Windows:

Acoustic blanket

Gypsum board

Tempered glass

Tempered Glass:Tempered glass acts as a sound barrier by constructing two or more layer with an air cavity in-between them. (Binggeli, Pp. 407) Delivers better sound attenuation than non treated glass.

Doors:

Application of continuous bead for acoustical caulk

Metal acoustical door

Metal acoustical door

Application of continuous bead for acoustical caulk

Acoustical caulking: A sealant used to reduce sound transmissions between adjacent spaces.

Metal acoustical door:Provides sound transmission loss due to metallic properties.

Ceiling:

Sound Masking:Studies have shown that people are sensitive to background noise. Since the Chapman Building lacks acoustic design in some office spaces, they decided to use a technique known as sound masking. This is when two distinctive sounds can be heard simultaneously; they tend to obscure one another. (Binggeli, Pp. 384)

Acoustic ceiling tiles: Designed to improve sound quality and block noise transmission.

Acoustic ceiling tiles:Suspended ceilings often have these in combination with a modular grid system to cover plenum.

Curved Acoustical Canopies: Hung toward sound source.

HVAC System:Using high quality equipment helps eliminate mechanical system noise.

Auditorium Acoustic Ceilings

Classroom Acoustic Ceilings

Ceiling:

Cubicle area: Too noisy; acoustic tile ineffective; required white noise equipment

Cause: Elevator opening onto cubicle office space used by massesCause: Cubicle walls made of hard surface material

Open stair area issues: Too noisy; sound can echo from second to third floor.

Ineffective Ceiling:

Furniture:

Specular Reflection: Sound bouncing/reflecting off hard polished surfaces (Binggeli, Pp. 385). In this space carpet was used to help reduce this effect.

Resilient tiles :Have foam backing, which allows them to attenuate high frequencies (Binggeli, Pp. 399).

Furniture:

As stated in Building Systems for Interior Design, fully upholstered seating minimizes the difference in sound between the times when the room in full of people and when it is almost empty.

Furniture:

Upholstery:In the Binggeli book, he stated that “Deep, porous upholstery absorbs most sounds from mid-range frequencies upward” (Pp. 399)

Partitions:

Acoustic blanket

Gypsum board

Aluminum foilrigid insulation

Used in the Chapman Building offices. Have metal backings and fiberglass substrates, which allow the panels to have a higher sound absorption standard. (Binggeli, Pp. 397)

Partitions:

Sound Transmission:Whenever spaces share an opening, sound travels through the opening into adjacent spaces as sound finds the path of least resistance (Physics, Prof. Smith). By using airtight sealants such as rubber for example, we eliminate sound transmission between rooms.

Figure 1: Shows acoustical door jamb or panel seal. (Binggeli, Pp. 409)

Office:

Treated Cement : Was used in the main staircase of the office interior. Because it is a reflective surface, it has poor acoustical qualities.

This Zen garden was strategically placed in an open area of the office to assist with sound masking. It has sand and pebbles to help absorb sound as well as running water to mask other noises.

The vertical space was designed to allow some of the remaining noise to travel upward and out of the main office space.

Banquet room:

“Reverberation is the persistence of a sound after the source of the sound has ceased”(Binggeli, Pp. 380). Binggeli also states that “the reverberation time for a room should be appropriate to the use of the space”. For example, in music halls a longer reverberation time is practical because it allows the sounds of the instruments to linger, creating rich harmonious sounds. In lecture halls, shorter reverberation times would be ideal because it allows for speech clarity. (Binggeli, Pp. 380). Angled ceilings affect sound reverberation as well because in spaces with horizontal ceilings, sound reverberates uniformly up and down. This causes difficulty for listeners trying to hear from a distance. As opposed to angled ceilings, allow sound reverberation in all directions facilitating the hearing capacity for listeners.

Carpet:The only floor finish that absorbs sound (Binggeli, Pp. 398).

Mechanical room:

Massive materials:Although painting these materials diminishes their acoustical quality, they generally reflect sound and resist mechanical vibrations (Binggeli, Pp. 387).

Outdoor:

Planting grass and trees in large quantities provides a good amount of sound absorption.

In the Chapman Building, there are no doors on the exterior of building except the ones leading towards the courtyard. This is most likely because the pathways throughout the building are high- traffic areas, meaning there will be lots of noise. Since one of the functions of the building is to serve as classrooms, this technique blocks out most of the unwanted noise. Providing a waterway, is also an effective way of absorbing unwanted noise.