Noise in a restaurants is like using salt where too much is unhealthy and it ruins your meal

Dining out isn’t just about the food. People are looking for a dining experience that is memorable and enjoyable. It’s an experience for all the senses. If you’ve ever left a restaurant feeling irritated or exhausted, you know how your hearing plays a big role in the experience. Most restaurants have a serious noise problem that is affecting customers and staff and therefore the business.

Article illustration, blog post

How does noise affect our health? 

For most of us being exposed to noise is just an annoyance that will pass when we leave the noisy space. But did you know that being exposed to unwanted noise can lead to hearing loss [1] tinnitus [2], hyperacusis [3] and cardiovascular disease [4]? And not to forget stress, anxiety, insomnia, high blood pressure and increased heart rate! [5]

Let’s take a real scenario: if we’re conversating and you are listening to me at a 1-meter distance it will mean around 60 dB, it’s a safe and healthy noise level. But if you would be at the same distance and I’m playing the trumpet with around 115 dB, it will most likely damage your hearing. 

You should know that hearing damage is not only about how loud a noise is. It highly depends on how long you are exposed to a constant noise level. For example, being one hour in a noisy environment of 94 dB can cause hearing loss. In some cases, hearing loss can be temporary. However, it can become permanent when vital parts of the ear are exposed to excessive noise and have made damages that can’t be repaired. For all these reasons it’s important to be aware of the noise impact and take safety measures for a proper sound reduction. 

Restaurant noise, can it be discrimination? 

Several studies have been made [6,7,8,9] and unfortunately, an average noise level of 94 dB is not an exception in restaurants. It influences the customers and their experience but the people working in restaurants are exposes to these noise levels too. For a long time, the top 1 complaint from visitors of restaurants, cafes and bars were about the service. But within few years, the number one complaint has become noise [10]. Most of us are just irritated about the noise. The ones with hearing impairments dare to go even a step further. They are not talking about irritation but discrimination [11]

Article illustration, Rockfon, blog post, insight, graph, noise, hearing damage

How loud and how long before getting hearing damage

Huh? Can you repeat that? 

According to research [12], half of the visitors of a noisy restaurant remain seated despite the high level of noise but will never come back. I am sure we’ve experienced getting the wrong order just because of bad speech intelligibility in a noisy environment, right? 

People would visit a restaurant more often if the indoor acoustic environment would be improved. And it seems that an acoustic improvement is urgent as 8 out of 10 people have problems holding a conversation in a dining area [12]. Especially when the Lombard effect occurs. And that is something you really want to avoid.

Are you familiar with the “Lombard effect”? I am sure, you have experienced it when visiting a busy restaurant or bar. It happens as we naturally talk louder when the noise levels around us rise, and that creates a vicious cycle of noise pollution. The result is a cacophony of deafening conversations. 

 

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Kill the noise, not the vibe 

How can the sound of a restaurant make dining out more enjoyable? 
It has an easy answer: By controlling the noise levels. But the implementation can be quite a challenge. It’s all about the right balance between speech intelligibility and speech privacy. And that’s where it becomes tricky. You don’t want to have a restaurant that is too quiet.
This can be quite unpleasant for the guests as they can hear everything you say but you also can hear everything they say. Using music as a masking tool can be very helpful. But don’t forget to keep background music in the background. 

When it comes to the built environment there are a lot of guidelines or standards to control the indoor acoustic environment. So, what about restaurants?  

There are some national standards about acoustics but it’s just a handful and they differ from country to country. The most used parameter for measuring acoustic comfort is the reverberation time. It’s the time needed for the sound to “fade away” or decay in a closed space. Requirements for reverberation times go from 0,30 to 1,20 seconds. 

Table 1: Comparison of different standards for reverberation time (RT)

Country

Reverberation Time 

Comments

Source

Norway

class A: 0,33 sec. 

class B: 0,41 sec. 

class C: 0,51 sec. 

class D: 0,69 sec

Depends on the ceiling height [A]. Example is with ceiling height of 2,60m 

NS 8175: 2012 

Sweden

class A: 0,50 sec. 

class B: 0,60 sec. 

class C: 0,60 sec. 

class D: 0,80 sec

 

SS 25268: 2007 

Finland

≤ 1,20 sec. 

STI ≥ 0,60 

Ääniympäristö Ympäristöministeriön 
ohje rakennuksen ääniympäristöstä, 2018
 

Spain

≤ 0,90 sec. 

Empty room 

“Guía de aplicación del DB HR. Protección acústica frente al 
ruido”. CTE Ministerio de vivienda. 
Ministerio de Ciencia e Innovación. (versión borrador 6, 23/03/2011).
 

Australia

0,60 - 1,00 sec. 

        ≤ 0,80 sec. 

        ≤ 1,00 sec. 

See note [B] 

See note [B] 

Hotels (bars and lounges) 

Industrial Buildings (lunchrooms) 

Office Buildings (cafeterias) 

Health Buildings (dining areas) 

Restaurants, cafeterias, coffee shops and food courts 

AS/NZS 2107:2016 

Acoustics - Recommended design sound levels and reverberation times for building interiors 

[A] class A: RT= 0,13 x h, class B: RT= 0,16 x h, class C: RT= 0,20 x h, class D: RT= 0,27 x h 

[B] Reverberation time should be minimized for noise control 

 

Talking to a chef or a restaurant owner about the reverberation time, he or she has no clue what you are talking about. What works best is letting them experience it and hear the difference. 

Keep the noise levels to a minimum for a better customer experience  

Everything you see in a restaurant will influence how a restaurant is perceived. It also covers how it sounds. It starts with the foundation, the room itself. The shape and dimensions influence the indoor acoustic environment. Soundwaves will reflect on hard smooth surfaces, so avoid parallel walls as they can create irritating horizontal reflection. And the bigger the volume of the space, the more reverberant it will sound.  

For designing restaurant and bar areas, the most popular trend is “Less is More”.  
Originally, it’s a phrase said by the architect Ludwig Mies van der Rohe in 1947 and presents the minimalist interior design representing a sense of order and essential quality where it increases engagement in the dining experience. But with the heavy use of hard smooth surfaces like glass, wood, concrete and plasterboard also rises the sound levels. These materials reflect the sound rather than letting it die away. The result is a cacophony of sound. 

 

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Another feature of the restaurants is to let the customers get the full experience and see the kitchen area. The open kitchen aspect welcomes a significant amount of noise and disturbances into the dining area. It’s the point of the central activity, where all the magic happens. But with a mixture of loud unpleasant sounds, it can also create an evil noise demon. 

Tablecloths help reduce the sound of silverware and glassware clattering on tables, but it will not have a huge influence on lowering the reverberation time. The ceiling and walls may be the biggest culprits of amplifying sound in your restaurant, but there are ways to get them to stop noise from spreading. Adding an appropriate number of soft materials to the dining area will reduce the reverberation time dramatically and help to accommodate the guests and less harmful for the restaurant employees. You can make your ceiling “soft” by installing sound-absorbing ceiling tiles and that has an impact on acoustic comfort. They will absorb the sound instead of letting it bounce around.  

Yak, that sounds bitter! 

What many people don’t know is that noise also affects your taste. Researchers from Unilever and the University of Manchester found evidence when eating in the presence of loud compared to quiet background noise the taste of the food changes. The food’s saltiness, sweetness and even “liking” diminished when the food was eaten under noise conditions of 75 -85 dB [13]. The background noise influences our perception of food and guests may not experience the food that the chef had in mind.  

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Controlling acoustics is making money! 

Customer loyalty and satisfaction are crucial to the long-term success of any business, but it’s the cruel truth for restaurants, cafés and bars as guests are not only paying for the product being served but also for the experience starting when they enter through the door. The noise levels have a huge influence on overall satisfaction [14]. Research shows that if the background noise increases, the willingness to spend time and money in a restaurant also decreases [15] 

It’s no surprise that restaurants have grown louder over the past few decades, and people really are annoyed by the noise while dining. This is not to say that all restaurants are the same, or should be silent, but an acoustically well-designed restaurant can elevate the space and make it sound more beautiful and create a welcoming and lively atmosphere. 

Are you designing or revamping a restaurant? Watch this video about the influence of acoustics and hear first-hand from the owner of a MICHELIN Guide Restaurant in Holland, about the difference the new acoustic atmosphere has on his customers and staff. The restaurant turned from an unpleasant experience to an outstanding experience for the customers to enjoy great food and comfortable soundscapes while the employees had a safe and comfortable workspace. 

The owner of Restaurant Calva says: 

"We're really able to connect with our customers, so you feel like you can spoil them."

Sources: 

[1] Mayes Jan L. (2019), Urban noise levels are high enough to damage auditory sensorineural health 

[2] WebMD (2019) Medical Reference, reviewed by Minesh Khatri, MD on Nov. 12, 2019 https://www.webmd.com/a-to-z-guides/understanding-tinnitus-basics 

[3] Sharon Goodson, ASHA (2015), MA, CF-A, Palo Alto Medical Foundation and Raymond H. Hull, PhD, Professor of  Communicative Disorders and Sciences, Audiology, Wichita State University https://www.asha.org/uploadedFiles/AIS-Hyperacusis.pdf 

[4] Münzel T. et al. (2018) Environmental Noise and the Cardiovascular System, Journal of the American College of Cardiology, Volume 71, Issue 6, 13 February 2018 

[5] Joy Victory (2019), Healthy Hearing, Oct. 21, 2019, https://www.healthyhearing.com/help/hearing-loss/noise-induced-hearing-loss 

[6] Oticon Study (June 2018) “Huh? What are the noisiest restaurants in top food cities in America?”  

[7] Rusnock C & McCauley Bush P (2012) Case Study, Journal of Occupational and Environmental Hygiene, 9:6, D108-D113 

[8] To W & Chung A (2015) “Restaurant noise: Levels and temporal characteristics” 

[9] Lau S et al. (2017), A comparative study of restaurant sonic environments in Singapore, Macao SAR, and Hong Kong SAR   

[10] Top complaints of diners Zagat Survey 2018, https://zagat.googleblog.com/ 

[11] https://www.washingtonpost.com/lifestyle/food/for-those-with-hearing-impairments-restaurant-noise-isnt-just-an-irritation-its-discrimination/2019/06/14/0223d722-8def-11e9-adf3-f70f78c156e8_story.html 

[12] Action on hearing loss, Speak easy: Hearing the views of your customers, Luke Dixon 2015 

[13] Woods AT et al. (2010), Unilever R&D Vlaardingen, The Netherlands, School of Psychological Sciences, University of Manchester, UK, “Effect of background noise on food perception” 

[14] Raab C et al, (2013). Restaurant Customers’ Perceptions of Noise and their Satisfaction and Loyalty Behaviors, International Journal of Hospitality and Tourism Administration, 14:4, 398–414. 

[15] Bottalico P (2018), Lombard effect, ambient noise, and willingness to spend time and money in a restaurant, The Journal of the Acoustical Society of America 144, EL209