By Peter Janis
In a 2015 dining trends survey by Zagat, the number two complaint by patrons, after service issues, is excessive ambient noise. We have all had to speak louder to be heard by dining companions sitting right next to us. Bottom line is this problem must be fixed or it will affect your bottom line. If acoustics are poor, it will only serve to leave a bad taste in the mouth of your patrons, no matter how great the menu.
When you combine the sound generated by a music system, patrons trying to converse, staff communicating, and even ambient kitchen noise, it builds up and reaches a point where the energy in the room is no longer able to be absorbed or dissipated; moreover, design trends have evolved towards very open spaces (high ceilings) with hard, reflective surfaces (wood, metal, stone, tile, glass). This wide variety of sound in restaurants bouncing off these reflective surfaces increases the baseline volume, causing people to talk louder. The increased noise (noise floor) causes the music to be turned up and this cycle continues, resulting in a loud, unintelligible mass of noise.
There are presumptions out there that attempt to find justification for higher noise levels. Some think that the energy in the room makes it more exciting, which in turn will perhaps increase alcohol sales, or that the noise may cause tables to turn more quickly. Although these may hold some degree of truth with a segment of a younger crowd, the real question here is who is your clientele? Who are you trying to attract? More importantly perhaps, based on the Zagat survey response, who are you inadvertently turning off?
In order to resolve the excess noise, owners should incorporate acoustically absorbent materials into the restaurant, either as part of the initial design or as an aftermarket addition. In the design phase, acoustic panels can be strategically placed within the ceiling structure or on walls and incorporated into the design of the space. Similarly, post construction, ceilings and walls offer opportunities to help tailor the acoustics of the space.
Some owners hesitate to address the acoustics or noise problem in their restaurants believing the cost to be prohibitive. While a concert hall or top-end recording studio might see material costs reach $50,000 to $100,000, the same is simply not true for most restaurants. In fact, most restaurants can be acoustically “repaired” for between $2,500 and $10,000, depending on the size.
Acoustic panels are essentially porous devices that are either hung on the walls or from the ceiling. Sound waves enter the panels, causing the minute fibres to vibrate. This thermo-dynamic process essentially converts sound into heat. Since most restaurants are in commercial areas, attention must be paid to fire safety. Panels that are safe for use in commercial applications will have been tested by an independent lab to ensure they pass ASTM-E83 (United States), Can/UL S108 (Canada), or EIN-36535 (Europe) standards.
Selection & Placement
When using a high-density glass wool panel, for instance, the most common choice is to install between 20 to 25 per cent wall coverage. Alternatively, you can hang panels from the ceiling. This works equally well. Placement is not critical. It is more about controlling and reducing the excessive energy build-up in a room by hanging panels wherever convenient.
The thickness and density of the panel will dictate the absorption range. The thicker the panel, the lower the frequencies you will absorb. The most common thickness is 2 in. (5 cm). This will easily absorb energy down into the lower registers of the voice and help reduce low frequency rumble from the music system. If under budgetary or space constraints, you can get away with a 1-in. (2.5-cm) thick panel, which will help with most frequencies in the speech range. On the other hand, if live performances are held in the restaurant, you may want to consider adding a mix of 3-in. (7.5-cm) thick panels to help control the deeper bass.
A common concern is how the panels will integrate with the existing esthetics of the room. Most panel manufacturers offer basic neutral stock colours but panels can also be covered on site using any decorative fabric so long as it’s breathable. More recently, a paintable panel has come to market that enables the user to spray the panel on site using standard latex paint. Available with straight or beveled edges, shipped in a white finish, paintable panels can also be used as an artist would use a canvas.
If you are handy with a screw gun, you can easily fix the acoustics in a restaurant in a matter of hours. Once done, you can be sure that customers will return… so long as the food and service are up to their expectations!
Peter Janis is president of Primacoustic, a division of Radial Engineering Ltd. Primacoustic is a market leader in high performance acoustic products, offering a wide array of acoustic solutions that span all market segments.