Room Acoustics, Speech Intelligibility and Sound R

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Loud Restaurants Reduce Customer Comfort (and Spending)

Noise doesn’t just make a space feel busy — it changes behaviour.

Research from Cornell University’s School of Hotel Administration found that:

Higher noise levels increase stress

Guests spend less time seated

Customers are less likely to linger or order additional drinks and desserts

Another study published in Environment and Behavior showed that excessive reverberation reduces perceived comfort and enjoyment — even when food quality remains high.

👉 Great food can’t fully compensate for a stressful sound environment.

Conversation Is a Core Part of the Dining Experience

People don’t just come to restaurants to eat — they come to talk.

Poor acoustics reduce speech intelligibility, meaning guests must:

Lean in

Repeat themselves

Speak louder than normal

This is particularly damaging for:

Group dining

Older customers

Business lunches

Family restaurants

Good acoustic treatment improves clarity without making the space feel “dead”. The result? Relaxed conversations, longer stays, and happier guests.

Better Acoustics Improve Staff Performance Too

It’s not only customers who suffer in noisy restaurants.

According to studies in Applied Ergonomics:

High noise levels increase staff fatigue

Verbal errors increase in loud environments

Stress levels rise over long shifts

For staff, poor acoustics mean:

Missed orders

More mistakes

Higher burnout

Reducing reverberation and background noise creates a better working environment — which directly improves service quality.

Acoustic Design Supports Your Brand and Atmosphere

Sound is part of your brand identity, whether you plan for it or not.

Fine dining should feel intimate and calm

Cafés should feel lively but comfortable

Bars should feel energetic without being overwhelming

Acoustic design lets you control the vibe rather than letting noise take over.

Well-designed restaurants don’t just look good — they sound right.

Modern Acoustic Treatment Looks Good (and Sells Better)

One common concern is that acoustic panels will ruin the look of the space. In reality, modern solutions can be:

Integrated into ceilings and walls

Designed as decorative features

Custom colours, textures, and shapes

From timber slats to fabric panels and ceiling baffles, acoustic treatment can enhance design, not fight it.

Acoustic Upgrades Deliver Long-Term ROI

Unlike promotions or refurbishments that date quickly, acoustic improvements work every day:

Improved customer satisfaction

Longer dwell times

Better online reviews

Higher repeat visitation

Multiple hospitality consultants report that modest acoustic upgrades often deliver some of the highest returns on investment of any interior improvement.

And once installed? They keep working — quietly.

Final Word: People Don’t Notice Good Acoustics — Until They’re Missing

Customers may not compliment your acoustics, but they will remember how your restaurant made them feel.

Calm. Comfortable. Able to talk without shouting.

If you want guests to stay longer, enjoy themselves more, and come back again, good acoustics are not optional — they’re essential.

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Restaurant Acoustics: How to Reduce Noise & Improve Guest Experience

Why Restaurant Acoustics Matter

When diners choose a restaurant, they think about food, service, and ambiance. But one hidden factor can make or break their experience: restaurant acoustics.

Too much echo, loud chatter, or blaring music can leave guests frustrated. In fact, many restaurant reviews now mention noise levels—and noisy spaces often get lower ratings.

Good acoustics create comfort, encourage conversation, and keep customers coming back.

Common Restaurant Noise Problems

Most restaurants struggle with noise because of design choices:

Hard Surfaces: Glass, concrete, and tile reflect sound.

Open Floor Plans: Large dining areas amplify chatter.

Background Music: Poorly balanced sound competes with voices.

Kitchen Spillover: Noise from open kitchens can overwhelm guests.

The result? Guests leave earlier, spend less, and may not return.

How to Improve Restaurant Acoustics

The good news: reducing restaurant noise doesn’t mean losing style. Here are proven solutions:

Acoustic Panels & Ceiling Baffles Designed to absorb sound, these panels reduce echo while blending into décor.

Soft Furnishings Upholstered seating, curtains, and rugs naturally absorb sound waves.

Balanced Sound Systems Use sound-masking or distributed audio to keep music enjoyable, not disruptive.

Design with Acoustics in Mind The best time to plan acoustics is during construction or renovation—but it’s never too late to improve.

The Business Impact of Good Acoustics

Better Reviews: Guests often mention noise in feedback.

Higher Revenue: Comfortable diners stay longer and order more.

Lower Staff Stress: Clearer communication improves efficiency.

Investing in restaurant noise reduction pays for itself through happier guests and repeat business.

Final Thoughts

Great dining is about more than food—it’s about atmosphere. If your restaurant struggles with noise, investing in restaurant acoustics will transform the guest experience, improve reviews, and strengthen your brand.

👉 Ready to improve your restaurant acoustics? Contact us for a consultation and discover how simple sound solutions can boost your business.

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Creative visual and acoustic design of restaurants

Hospitality acoustics

  Can visual design freedom be increased with broader acoustic material choices?

 ·         Excessive noise in restaurants is a widely acknowledged problem,

·         Reducing noise often compromises the visual aesthetic e.g. glue-fix polyester panels,

·         Visual design, and acoustic performance can and should be harmoniously optimised,

·         Creative options are readily available, so why not use them? 

Noise impacts reduce the time spent in a restaurant, the amount purchased, the likelihood of return custom or referrals.

 ·         Noise has an effect on the perception of food and drink1.

·         The journal Nature, recently published - “the more noise in an establishment, the more dissatisfied your customers will be, and the less time and money they spend there”.

Design of restaurant acoustics is specific to enhancing the customer experience and must be crafted to achieve the desired atmosphere whilst meeting practical and cost limits.

 ·         Restaurant noise is a balance between the occupancy (including the occupancy density and seating area per customer) and a good acoustic environment2. 

Example of one approach to optimisation;

 Acoustic design is not guesswork. Done properly, it reduces the risk of;

 ·         Underperformance due to insufficient or inappropriate materials and/or placement,

·         Overspending – typically uninformed approach of guessing,

·         Compromising the ambience

  1.     Spence, C. Noise and its impact on the perception of food and drink. Flavour 3, 9 (2014). https://doi.org/10.1186/2044-7248-3-9

2.        To, Wai Ming; Chung, Andy W. L.1. Noise in restaurants: Levels and mathematical model. Noise and Health 16(73):p 368-373, Nov–Dec 2014. | DOI: 10.4103/1463-1741.14441

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Restaurant Noise Reduction

This is a snapshot of one of the calculators we use - for restaurants. If you are a restaurant with noise problems, we can provide a lot more than simple area or reverberation time calculations.

Using this tool, we can help decide how much to reduce the noise based on average occupancy and human loudness perception. Some may want it fairly quiet but others will want a bit more ambience. This will optimise the spend on acoustic treatment and prevent what we commonly see, which is too much absorption causing a lifeless restaurant.

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soundproof meeting room fail

Just went to a meeting a newly fitted out plush office, only to see this. It is a purpose designed meeting and videoconferencing room. You can hear almost everything that goes on outside, and inside is boomy to the point of distraction (only 25mm thick absorbers). The speakers are a hindrance rather than a help. I wonder if they know how much productivity is being lost and why they don't ask whoever designed to fix it - in my mind they asked for a meeting V/C room and didn't get one. I can't even imagine what consideration was given to anyone with anything with less than perfect hearing!

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Rubber waffle pads under A/C compressors - total waste and environmental nightmare

Why are we still doing this? This has been going on for as long as I can remember, and with absolutely NO value in terms of stopping vibration. Almost every piece of waffle pad is crushed beyond belief, and so will never work as hoped. Even if it wasn’t crushed, getting the correct deflection to make some reasonable isolation would be extremely difficult.

Almost all isolators need to be correctly loaded and deflected to work as designed. If they are compressed too much or not enough, they will not work as isolators, and in some cases will make the transmission of vibration worse (when the resonant frequency of the improperly loaded isolator matches the vibration of the load.

The example above shows resonance at 10Hz. Attenuation starts at about 20Hz and increases as frequency goes up. At 50Hz where motors run, significant attenuation is delivered.

A correctly loaded isolator must be deflected the correct amount, often about 10% of original height. It is important that the shape does not unduly change and that the isolator material does not harden over time - which rubber does. Sylomer from Getzner is a good example of a suitable vibration isolator as it can be loaded/deflected properly, it maintains it’s shape and doesn’t harden significantly over time.

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Complete studio service with design, manufacture, build and test has benefits

When building a studio, the benefits of a team with lots of experience is obvious. They know about what you want to do in there and the practicalities of layout, connectivity, gear etc.

However, there is a big benefit to having the design, manufacture, supply and build (and sometimes test) all done by the one team. It means you get plans that specify components that are readily available and can be bought or made. We see too many reports that say things like ‘use a suitable attenuator here’ or similar statements. All of the items like isolators, plasterboard etc, are known to work together and have methods for installation and finishing. Provision for fresh air, wiring, access, etc, are all taken care of as they have been done so many times before. The up front cost is easily saved by avoiding missed items, things that aren’t easy to source or implement or actual failure of the outcome.

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Making a big school sound really good without too much fuss.

Installing some sort of acoustic panels to large areas that have minimal fixing is difficult and expensive. These typical school halls usually have steel roof beams that are quite far apart, making it very hard to fix anything to them. You can’t fix to the underside of the tin roof or the thermal insulation either.

UltraQuiet SPAN is designed to solve this problem.

Very high acoustic performance – suitable for music, drama etc

Impact resistant, ideal for sport halls

Available in 8 colours or custom printing

Low maintenance

Moisture & chlorine resistant Ideal for pools and high – humidity areas

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What is the right absorption for small meeting rooms and teleconferencing?

Answer: The smallest amount that makes the room echo not a problem. (Also, the lowest cost, easiest to install and most practical).

The common misconception;

If we have two types of absorbers, each with a different NRC (Noise Reduction Coefficient), then we need more of the one with the lower NRC to achieve the same total absorption.

Example;

Absorber 1 – NRC 0.6

Absorber 2 – NRC 0.9

You might think that since absorber 2 is has an NRC 1.5 times that of absorber 1, you would need 1.5 times as many square metres of absorber 1 to get the same effect – but this is wrong.

e.g.

3 square metres of Absorber 1 (NRC 0.6) = 1.8 metric Sabins of absorption

2 square metres of Absorber 2 (NRC 0.9) = 1.8 metric Sabins of absorption

However, this is misleading because NRC is an average figure that does not give enough information. NRC is a gross oversimplification that hides the relationship between absorption and frequency.

The graph below shows 3 very different absorbers, all with the same NRC (NRC is simply the average of absorption coefficients from 250 to 2000 Hz).

The common problem;

The previously described misconception is used (generally because it is presumed cheaper) and lots of wall and ceiling space is covered in thin absorbers. This may result in a reasonable effect as a single figure, and meet WH&S requirements for total noise dose, it will not be suitable for speech or teleconferencing.

This is what happens;

A standard office or meeting room which is too reverberant (plain room) is not overly improved with 15 square metres of 12mm polyester panel. High frequencies are absorbed too much leaving the room feeling dead. Low frequencies are not absorbed making the room sound boomy. Both of which make speech unclear, especially if on the phone or in a telemeeting. This is because the polyester panel has much more high frequency absorption than low or mid frequency absorption*.

By contrast, the use of a much smaller amount of thicker absorption results in a room highly suited to speech and phone or teleconferencing. This is because thicker absorbers also cover the low and mid frequency range*.

* the absorption coefficinets used for the absorbers and all room materials are included at the end of this article.

Not only does the application of a smaller amount of thicker absorption result in a better sounding room, it is a lower cost installation. Quite clearly, 4.5 square metres of thicker material is only 30% of the 15 square metres of thinner material, and has a lower material and installation cost.

It is also much more realistic to be able to apply this amount of absorption in a normal office as much space is often occupied by windows, whiteboards, A/V equipment etc.

As well, you could keep applying more thinner material and NEVER get a decent sounding room. In fact it would get worse because the high frequency would be even more over absorbed and the low frequency would remain unchanged.

The Australian Standard AS/NZS 2017:2000 recommends the following reverberation times for this type of room;

OFFICE BUILDINGS

Board and Conference Rooms - 0.6 to 0.8s

Executive office - 0.4 to 0.6s

Video/audio conference rooms - 0.2 to 0.4s

Benefits of using the right type of absorption;

* Lower cost

* Less wall and ceiling space used

* Easier installation

* Much better sound for speech and teleconferencing

* More likely to get approved because of all of the above

DATA FOR THE ROOM

Room volume: 22 m3

Temperature: 23 deg.C

Rel. humidity: 40 %

Total surface area: 48 m2

Surface area X: 18 m2

Surface area Y: 15 m2

Surface area Z: 15 m2

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Practical Test & Measurement: Objective Listening Effort Evaluation

This article by Hans W. Gierlich and Jan Reimes - two top experts in communication technologies from HEAD acoustics GmbH - details the expanded effort for understanding speech under noisy conditions, and addresses a new approach recently introduced by HEAD acoustics, resulting in a new model that can be used to test active noise cancellation (ANC) performance in complex scenarios where the system needs to distinguish between speech signals as part of the background noise and speech signals directed toward the users of these devices. This article was originally published in audioXpress, April 2020.

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Influencers: David Lynch’s Cinematic Disruption Starts with Sound

The "Eraserhead" and "Blue Velvet" director, who received an honorary Oscar this year, is one of IndieWire's craftspeople shaping the art of cinema today.

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Music and the brain

Music deeply affects us emotionally, and individually—and now we know that our relationship with music provides a unique opportunity to gain further insight into the workings of the brain itself. We discuss the latest in music research with one of the editors of The Oxford Handbook of Music and the Brain. Hear about why we may prefer particular types of music, how being a musician can change the brain over time, and what happens to our musicality as we age.

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Optimal use of absorption in a room

It seems to be common to cover walls, or large parts of them, in relatively thin absorption (9 to 15mm thick). This may be because it is heavily advertised, seems to be lower cost or because it means less paintwork needs to be done. More than likely though, it is done out of ignorance. The thought that more is better is a fallacy for two reasons;

It is not a linear addition. If reducing the reverberation time on the room to half it’s current level requires 5 square metres (for example), the next 5 square metres also halves modified level i.e. the first five square metres goes from 100% to 50% and the second five square metres goes from 50% to 25%. So there is an optimal amount that yields the best reduction in reverberation time square metre (or dollar).

Thinner materials absorb more high frequency than low frequency. Over use of thin materials results in rooms that feel and sound muffled and dead. The single figure RT60 may be low but the speech transmission index will still be poor. Ultimately over use of thin materials has not solved the acoustical problem and cost a lot.

The graph below shows the change in reverberation time from an empty room to that with 5, 10 and 15 square metres of absorption. Clearly, the first 5 square metres has the greatest effect. The room is 4 x 3 x 2.4m

The far smarter option is to use a lesser amount of thicker absorber. Most commonly 50mm thick absorbers are used because they absorb from high frequency down to the low end of the spectrum of speech. This creates a balanced reverberation time that sounds natural. The cost is similar to overusing thin materials because a lot less area is used even though the 50mm thick absorber is generally more expensive than the thin one.

As shown below, classroom hard has no absorption. Classroom thin is covered in thin absorption. Classroom thick is covered in thick absorption. Classroom nice is a moderate amount of thick absorption. Although the instance of covered in thick absorption may seem attractive in terms of speech transmission index, it would feel uncomfortably dead.

The reverberation times for the instances above are shown below. Again, classroom nice is obviously the room of choice as it would feel comfortable to be in.

In summary, it is far better value to use a lesser amount of thicker absorption. It will result in better speech transmission and a more comfortable feeling. The cost should be similar. If the room is used for any type of performance, music or A/V like teleconferencing or videoconferencing, this becomes even more important.

This may look simple but it produced this feedback;

I thought I would give you some feedback on our recent purchase of your acoustic tiles. We installed them a few weeks ago now and everyone is honestly shocked at how well they work. The room has gone from an echo filled, noisy box to a nice and (almost eerily) quiet conference room. Everyone's voice boxes and ears are thankful.

Thanks for your advice and service.

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Frequency’s Approach to Regenerating Lost Cochlear Hair Cells

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Poorly Designed Acoustics in Schools Affect Learning Efficiency and Well-being

Acoustic discomfort can harm the process of knowledge acquisition, interfering with attention and worsening student-teacher communication.

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New ‘Self-Cleaning’ Concrete Is Also Strong, Heat-Insulating and Soundproof

Building materials that clean themselves could save immense time and labor in homes and businesses, as well as reduce disease risk in settings such as hospitals. Now, researchers reporting in ACS Applied Materials & Interfaces have made a new type of concrete that is strong, heat-insulating and

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Doctors Now Prescribing Music Therapy for Heart Ailments, Brain Dysfunction, Learning Disabilities, Depression, PTSD, Alzheimers, Childhood Development and More - Didge Project

Music has proven time and again to be an important component of human culture and is now being seen as music therapy in many medical environments.