Ana Mernik Assignment 5: Acoustics Research

In architecture, acoustical engineering is the basis of interior space acoustics: the science of controlling a room's surface based on sound absorbing and reflecting properties.Things like sound pressure (the deviation from the average pressure caused by a sound wave), and audible frequency, and things more relevant to auditorium and concert hall buildings like...

reverberation time (the interval between the initial arrival of a sound wave and the last audible sound),
acoustic transmission (procedures that can transfer sound between parts of buildings), and
acoustic impedance (pressure made from vibrations)

...can be calculated and applied to create comfortable, productive, and sound intelligible places.
For example, in spaces where reverberation is too high, it becomes difficult to understand what people are saying.

The general ABC's of improving acoustics: absorbing, blocking, covering.
Specifically for concert hall acoustics, volume, equalization, and reverberation are most important.

Volume: sound-pressure-level volume measured in units of decibels

Equalization: the volume of all frequencies in relation to each other; important in concert halls because it determines whether all the frequencies reach all members of the audience with that same volume relationship or if the concert hall distorts the relationships, and with it, sound; 40-12,000 Hz being the range of most sounds







Reverberation: reflected sound bouncing off surfaces until it stops; one second reverberation means that sound would lose 75% of its loudness within the first 1/10th of a second
The three are manipulated through materiality and geometry.

As far as materials go, acoustical panels work best when they have no finish material to interfere with acoustics. Fabrics, on the other hand, absorb sound and work well in recording studios. A substitute for fabric is perforated metal.



Ennead Architects designed the Bing Concert Hall on the Stanford campus in California. The main focus of the multi-functional complex is the concert hall, enclosed with a 12-inch thick concrete to isolate the interior. The geometry of the hall is an oval shape that provides optimal acoustics from every seat. The furthers seat is only 75 feet away from the center performance stage. Seating is enclosed in beech wood with specific densities and textures to strategically reflect sound. The big sculpted sails act as acoustic reflectors that are angled to also reflect, or absorb, sound.

 Diagrams of sound studies below.