Acoustics 101

The Importance of Acoustics

Sound determines the ambience of a room, setting the tone for how people will experience a space.  Although it is one of the most important factors in room functionality, acoustics is often an afterthought when it comes to the design of a space. Bad acoustics can lead to a multitude of issues, especially in settings where speech intelligibility is vital, such as lecture halls, auditoriums, offices and public spaces. The right acoustics will not only enhance your design, but when considered from the beginning, will save you time, money and resources. And with so many options available, acoustic treatments can serve as inspiration for your next project.

Let’s dive into the basics of acoustics and learn how to control it.

Understanding Acoustic Terms

NRC: Noise Reduction Coefficient (NRC) is the standard rating for how well a material absorbs sound. Ratings range from 0 to 1. An NRC of 0 provides no sound absorption, while an NCR of 1 provides 100% sound absorption.

STC: Sound Transmission Class (STC) is the standard rating of how many decibels are blocked by a product. This differs from NRC because STC focuses on limiting the transmission of sound through a wall. The higher the STC, the less the sound will transmit through a barrier, like from one classroom to another.

Decibel (dB): Decibel is the unit used to measure the intensity of sound. Sound travels in waves which in turn is then measured in Hz.

Hertz (Hz): Hertz is the unit used to measure the number of sound vibrations in one second.

Echo: Echo is the phenomena caused when a sound occurs in a space and can be clearly perceived 2 or 3 times following the initial sound. Echoes are more typical in large spaces where sound waves can travel a far distance, bounce off the surrounding hard surfaces, and in turn, is reflected to the listener. Echoes can be clearly heard above other sounds.

Reverberation: Reverberation, on the other hand, occurs when a sound is reflected back and forth after a prolonged period of time, even after the initial sound has ceased. Reverberation often occurs in smaller, more confined spaces where sound tends to overlap. This causes the reflected sound to be muffled and difficult to discern, which can become quite problematic, especially in a learning environment.