December 2012: Deck the Walls with Acoustic Panels

Have you ever been in a restaurant and not been able to hear the person sitting right next to you? If so, you may have experienced the acoustical phenomenon known as the “Café Effect”. Unbeknownst to most, the acoustics of any great restaurant or hospitality space are second in importance only to the food coming out of the kitchen. Read on to learn more about the Café Effect and how to tame this acoustic provocation.

The Café Effect is the phenomenon in which a speaker must talk over crowd noise in a reverberant space in order to be heard. As more people amplify their voice, the sound energy rises while the signal to noise ratio decreases, and the speaker must again raise his or her voice. If the reverberation time is not engineered correctly within the frequency range of human speech, this cycle will repeat itself until communication is almost impossible.

The key to taming the Café Effect is balancing the room acoustically. Sound absorbing materials such as acoustic panels and baffles can be installed to reduce reverberation time. The trick is to add enough absorption to contain the Café Effect but not so much as to keep the room from sounding lively. A lively restaurant will not only provide patrons with an enjoyable social atmosphere but will also provide sound masking that will keep a table’s conversation private.

Parc Restaurant Picture
Parc Restaurant with recommended panels around ceiling diffusers and bar area

Parc Restaurant in Rittenhouse Square in Philadelphia is one example that Metropolitan Acoustics has helped with the Café Effect. The bistro-style establishment had issues with a “tinny” sound and harsh high frequency content when the restaurant was full of customers. Along with the restaurant’s relatively low ceiling, all surfaces were finished with hard reflective materials. We recommended panels on the ceiling that fit within the aesthetic design of the space. This took the edge off of the sound but still kept the restaurant sounding lively.

Oyster House in Center City Philadelphia is another example of a restaurant that utilized Metropolitan Acoustics’ expertise in controlling their noise concerns. Acoustic ceiling panels were installed in areas that allowed for bar, dining room, and ductwork sound absorption. This provided attenuation in areas that were prone to high sound levels.

Oyster House
Oyster House with panels above bar and ductwork

The Café Effect is not only important in hospitality spaces; it is a valid concern in any gathering space where group communication is a must. James Whitlock of Marshall Day Acoustics and George Dodd from the Acoustics Research Centre stated in a 2006 paper that controlling the Café Effect is a major step toward proper classroom acoustics. Their paper concludes that children have a detrimental response to the Café Effect in terms of speech intelligibility and response to background sound.

As Parc Restaurant and Oyster House have benefited, incorporating the correct amount and type of sound absorbing material at the proper locations will help any space tame the Café Effect leaving behind only enjoyable conversation and empty plates.

January 2013: An Apple a Day
November 2012: Playing Smart