Acoustic Comfort: a pending subject for Sustainability?

In a previous article in this blog, where I talked about Mobility & Transportation, we were able to address the use of new technologies to combat the Covid-19 pandemic, control the return to the new normal and also to promote common efforts for Sustainable Development at a global level. Particularly applying the measurement of seismic noise in order to assess the impact of human activity over the planet. Remember, "There is no 'Plan B' because we do not have a 'Planet B'" (quoting the famous phrase of the former United Nations Secretary-General, Ban KI-Moon) so it is vital to protect it, as well as its inhabitants.

In this fourth article from my blog on Sustainability Awareness, we will address a topic that is not very widespread among public opinion: acoustics and Acoustic Comfort as part of Sustainable Development.

We will talk about society’s perception, the clarification of sound & noise concepts, possible negative effects, difference between acoustic insulation & conditioning, the famous reverberation (or reverb), the problem of noise, we will take a look at innovation and new technologies… And we will address the apparent increase in social sensitivity to noise after the outbreak of the Covid-19 pandemic. All this followed by a brief presentation of the International Year of Sound 2020-2021 to finish with a new interview with three guests.

[Bustling night at Times Square before Covid-19, New York City (USA). Photographer: Joe Yates]

Until not many years ago, society rarely worried about noise or at least it was not perceived as a great nuisance, therefore it was not perceived as a health problem. Today the picture is very different and, fortunately, the majority of citizens are increasingly aware that acoustics in our environment is important for our well-being. Any contemporary society makes constant and intensive use of its buildings, placing anyone inside them during most of their daily activities.

This statement is undeniable in any corner of Europe and practically on the planet. So why has it taken so long to realize acoustics as an important factor in our society? It may be due to the saturation of noise, caused by very different and numerous sources, increasing due to the mass of the population or motor vehicles in cities. It may have been due to the most aggressive industrial production in our history. It may be because building users have been complaining for more than a century about noise from their neighbours. It may be because until recently we did not enjoy a good education and collective conscience that have opened our eyes (or ears, rather) and we have thought about it. Or it may be due to recent technological advancements that allow acoustics to be recorded, measured, quantified and interpreted as never before possible...

All these conditioning factors currently have a place, being the reasons that have pushed society to rethink its degree of concern and involvement... Probably accentuated after the Covid-19 pandemic, which seems to be increasing the sensitivity of the population to noise.

Before carrying on with this article, let’s glance at some of the diverse acoustics applications.

Acoustics applications

• Environment: study of outdoor sound, ambient noise and its effects on people and nature.
• Architecture & Construction: sound quality and control, insulation and conditioning.
• Industrial & Machinery: workers’ protection, systems performance and noise reduction.
• Underwater: submerged objects detection and oceans care.
• Biology: animal sound production and hearing.
• Physiology & Psychology: hearing, the brain and human perception.
• Music & Electronics: instruments, tuning and sounds processing.

Sound, noise and its negative effects

Often in popular words, sound and noise are used synonymously. However they are not the same… Sound is defined by physics as a phenomenon of propagation of mechanical waves, which may or may not be audible.

Noise is simply undesirable sound. It can cause discomfort and even serious health problems. Let's see some of its negative effects if the noise exposure is very strong and/or prolonged.

Negative health effects

• Hearing loss or even deafness.
• Difficult concentration, can cause headaches and attenuate the other senses.
• Insomnia and sleep disturbances that can lead to short-term memory loss, lack of body energy and feeding disorders.

• Increased stress and anxiety.
• Increased irritability and aggressiveness.
• Increased arterial hypertension and vascular risk.

Don't let noise silence you. Stand up for acoustic comfort!

Insulation, Conditioning and Reverb

In the world of architecture, construction and engineering there is often talk of acoustic "insulation" and "conditioning" to improve performance of sound or protection against noise (airborne, impact or reflection). Again there is a tendency to misinterpret its definition and purposes, although we are going to clarify them right now!

• Acoustic insulation is the set of materials, techniques and technologies developed to damp or attenuate the transmission of sound between spaces. In other words, acoustic insulation helps protecting us from sound and noise coming from outside or from other rooms. For example: isolate different apartments within a building block.
• Acoustic conditioning is the set of materials, techniques and technologies developed to control and improve the conditions for the propagation of sound waves inside a room or chamber, in order to obtain an appropriate acoustic environment related to the activity carried out in it. In other words, acoustic conditioning improves the quality of sound inside a room or room. For example: reducing reverberation in a meeting room or in a school classroom; or also regulate the reverb to be ideal for a music concert.

It is important to clarify that reverberation is what many people, in popular words, understand as “echo”. In physical terms, the phenomenon is very similar although they are differentiated by the distance and the time it takes for the sound to repeat. Let's say that the correct thing is to refer to the “echo” for long distances or large spaces (such as the sound reflected in the mountains or in a valley), while we will refer to “reverberation” in short distances or small spaces (for example, any room) or chamber.

Taking a more everyday example, reverberation generates the typical noise that we experience in a very noisy cafeteria or in the schoolyard, with hundreds of children playing and screaming.

There are more parameters (descriptors) that affect sound quality and noise transmission such as “speech clarity” or “intelligibility”, “hearing threshold” and “pain threshold”... We will address these details in future articles in greater depth.

 [Video: Reverberant vs. Anechoic chamber, by Juan Negreira – one of our interviewed guests in this article]

Noise: The Phantom Menace

As we have previously defined, noise is undesirable sound and can cause discomfort or serious health problems. It is a "phantom menace" as it is pervasive but no one can see it with their own eyes, nor can they touch it, nor can they smell it. Human beings often find it difficult to understand what they cannot perceive with various senses. Sound and noise are abstract concepts that we can exclusively perceive with one sense: hearing. And sometimes we cannot even perceive it since the human ear does not capture all the frequencies... But noise is there, hidden, and it affects us more than we think.

Without a doubt, the problem of noise is a great threat to the health and well-being of both people and the environment. The effects on health depend on the sensitivity, perception and tolerance of each person as well as the circumstances of each case, which makes it difficult to make a common scale or set minimum requirements for acoustic quality.

Innovation & new technologies

Currently, new technologies have guaranteed great advancements in the field of acoustics, especially for environmental acoustics and in building construction, in addition to having existing sound level meters (to carry out measurements, generate urban noise maps or evaluate the acoustic quality of buildings). Due to the digital age we can now “see the sound” (literally) thanks to acoustic cameras that dump the received data into an image or video with a colour scale (similar to thermal vision, for example). We can also locate noise sources using a probe that dumps the data into a coloured map as well. Very useful for engineering, for quality control, detection of design and production errors, or performance improvements.

[Video: Example of the features and operation of an acoustic camera (Norsonic), showed by Sound of Numbers & Acousticware]

Powerful acoustics software has been developed to design, analyse, evaluate, or classify entire buildings in record time and with near-foolproof precision, room by room and in full. Some tools already include three-dimensional models or simulations of acoustic behaviour, in addition to generating scientific data in tables and graphs (necessary to verify the results and to justify them before the increasingly demanding regulations). Drones can be used to acquire environmental data from the air, or reach points inaccessible or dangerous to a person...

[Video: SONarchitect workflow. Software for calculation of acoustic insulation according to ISO 12354. Developed by Sound of Numbers]

Important advancements have also been made in the design, production, installation and recycling of construction materials with high acoustic capacities, whether intended for acoustic insulation or acoustic conditioning. Below I name several examples in this list:

• New acoustic insulation with better features, recyclable or made from recycled materials, with greater resistance to fire and moisture.
• Thermo-acoustic materials, which improve both thermal and acoustic performance.
• Absorbent, diffuser or reflective panels with multiple product design options, for ceilings and walls alike.
• False ceilings that considerably reduce reverberation problems, even adjusting it according to the room usage.
• Shock absorbers for decreasing impact noise.
• Multilayer materials and accessories for construction systems that passively improve their performance as well as being lighter and smaller.
• New windows with frames and insulating glass that break acoustic bridges (filtrations).
• Furniture with acoustic capabilities.

[Example: Saint-Gobain Ecophon solutions for acoustic conditioning. Suspended sound-absorbing panels at KING offices in Barcelona. Photographer: álvaro San Román Gómez]

[Example: Saint-Gobain Ecophon acoustic solutions for Penza Concert Hall (Russia). Photographer: Olga Melekestseva]

All this has a counterpart: acoustics materials and services from specialized companies still seem expensive. They really are not if they are conceived for what they are: a good investment; relating the skill and precision of the work with the excellent results obtained. Although in the eyes of many professionals in the sector or investors, the acoustic projects are often restricted by the budget, fearing that it will be an extra cost for a new design or construction.

We must recognize the great work that acoustic professionals carry out, and the great technical and scientific training that it requires. Although we say that this high cost leaves out of play the majority of citizens who do not own a business where they can invest, patrimony assets or manage an institution. Let us hope that, in the progress towards greater acoustic comfort included in sustainable development, there will be a general increase in demand in order to make acoustic services cheaper, making them accessible and more affordable to a greater range of the population. 

Acoustic pollution: greater sensitivity to noise after Covid-19

The pause that the world is going through due to the consequences of the pandemic proposes us to rethink our relationship with the environment, whether urban or in nature. The progressive recovery processes of each country towards the new normal means the return of noise pollution.

The population's sensitivity to noise seems to be increasing after the calm that reigned during the quarantines or lockdowns, with some people suddenly becoming aware of the difference and even turning intolerant or allergic to noise. The world will never be the same, or at least our perception of it. Will society now become truly aware of the needs for a proper acoustic comfort?

[Night traffic of vehicles and pedestrians at Times Square, New York City (USA). Photographer: Joe Yates]

The most common sources of noise in urban areas are road traffic from motor vehicles (especially the noisiest motorcycles or old cars), beeps and sirens, rail and air traffic... Even large crowds of people in the streets, outdoor music events or large stadiums.

This situation should invite us to comprehensively rethink acoustic comfort as part of the Sustainable Development Goals (SDGs), with an eye put on the 2030 Agenda. Making improvements both in buildings & their activities and in urban mobility, we will be able to reduce noise pollution considerably to healthy levels.

[Sustainable Development Goals - SDG Knowledge Hub, a project by the International Institute for Sustainable Development (IISD)]

International Year of Sound 2020-2021

The International Year of Sound is a global initiative to highlight the importance of sound in all aspects of life on earth and will lead towards an understanding of sound-related issues at the national and international level. Due to the coronavirus pandemic the events calendar has been extended until next year, 2020-2021. 

The International Commission for Acoustics (ICA) is mobilizing its Member Societies and International Affiliates to promote best practices in sound during the year of 2020 to create an International Year of Sound (IYS 2020). This has been inspired by the efforts of La Semaine du Son (The Week of Sound), to achieve the approval by the UNESCO Executive Board for resolution 39C/49 “The Importance of Sound in Today’s World: Promoting Best Practices” to be included in the agenda for the 39th General Conference of UNESCO in 2017. The recommendation in that document (section 10) was then adopted as General Assembly Resolution 39C/59. The International Year of Sound 2020 follows naturally as an important contribution to that resolution.

[Video: Excellent introduction video for the International Year of Sound Campaign, 2020-2021, by UNTREF – National University 3 de Febrero (Argentina). *Recommendation: enable automatic subtitles translation]

Some details about the International Year of Sound (IYS 2020), the background, the structuring, the opportunities for sponsorship, can be found in the May 2019 Newsletter from the ICA President.

Interview: let’s talk with professionals

Some articles on this blog include brief interviews with international professionals and scholars. This time we have three guests dedicated to the acoustics sector. Let me introduce them before we start with the questions.

• Juan Negreira (from Spain). PhD in Engineering Acoustics at the University of Lund (Sweden) | National Concept Developer at Saint-Gobain Ecophon Spain.
• Rikard ?qvist (from Sweden). PhD in Engineering Acoustics at Lule? University of Technology (Sweden) | Partner at Acouwood AB, Adjunct associate professor at Ume? University | Blogger, Vlogger and Youtuber.
• Germán Sanguineti (from Argentina). Master in architectural and environmental acoustics | Acoustic consultant, noise and vibration control at Control de Ruido company.

1. First of all, thank you for your interest and for participating in this interview. Please describe us your current main functions or services as an acoustics professional.

-- Juan’s answer: “My main tasks as National Concept Developer at Ecophon deal with transmitting and raising awareness about the importance of acoustics, as well as developing conceptual solutions for the different actors involved in the construction process (architects, owners, municipalities, students and teachers, etc.). Moreover, I work in close collaboration with product development and research projects so that acoustic comfort can ultimately be met in the different building environments.

Moreover, I am visiting lecturer at Lund University (Sweden) and Adjunct professor at University La Salle (Barcelona), where I teach courses related with acoustics and vibrations.”

-- Rikard’s answer: “Our mission at Acouwood is to integrate acoustic perception and function in the sustainable buildings of the future. We focus on wooden buildings and provide acoustic consultation throughout the building process; From the early planning stage until detailed design in the construction phase and everything in between. We primarily work in close cooperation with Architects and Structural engineers, but acoustics tend to interact with just about every technical discipline involved in the building process. An acoustician gets a great overview, which I find very rewarding. I am also an adjunct associate professor at Ume? University (20%). I love education and have always kept one leg in the private sector and one leg in academia. I find the “field experience” gained when working with Acouwood invaluable as a Teacher.”

-- Germán’s answer: “I am thankful. My name is Germán Sanguineti, founder of the company Control de Ruido. It is dedicated to offering solutions and services to mitigate machine noise in work environments, noise pollution and to improve the acoustics of closed spaces. We provide specific acoustic engineering consulting services for the needs of the client and the project, in order to guarantee specialized support and guidance to make the best decisions.”

2. What contributions can your work field offer to our common effort towards Sustainability?

-- Juan’s answer: “At Ecophon, we have a fundamental respect for people and care strongly about all their environments. That’s why we continuously strive to improve production techniques, materials used, and everything else that adds to our environmental footprint. We do cradle-to-grave Life Cycle Assessment (LCA) studies of our products according to the international ISO 14025 and EN 15804 series of standards. These LCA studies form the understructure for establishing internationally standardised Environmental Product Declarations (EPD) for the different Ecophon products and system. Armed with that knowledge, we push ourselves to improve every phase, from sourcing raw materials (our products are made of more than 75% recyclable glass) and production to transportation and waste management.

Regarding the acoustic side, improved acoustics will definitely impact people’s wellbeing and thus a more sustainable society (optimisation of different resources). There are scientific studies showing that good room acoustics can speed up patient’s recovery and reduce errors in operation rooms of hospitals, enable quality teaching and learning in schools as well as increase productivity in offices.”

-- Rikard’s answer: “We believe that an increased use of wooden buildings can and will result in a significantly more sustainable building process. Not just by a reduced carbon footprint (raw material, decentralized manufacturing, transports…), but also from the human point of view. We belong in nature. Our species has evolved through millions of years and buildings have only been part of that process for a fraction of the time. By designing buildings that resemble nature, the quality of life can be improved. What better material to use for this purpose than wood? However, one of the biggest challenges when building in wood, is that acoustic measurement and evaluation methods need to be improved to give better correlation between objective and subjective ratings. Even if a concrete and a wooden building has exactly the same decibel rating, the perceived sound environment will be different. I believe the aesthetic aspects of the building are crucial, but they are challenging to quantify with objective numbers. The correlation between measurement and perception of sound in buildings, is something that both I and Klas Hagberg (founder of Acouwood) investigated in our PhD theses. Adequate sound requirements are a core concept of sustainability. Wise design choices in the building process require proper goals and reliable methods of verification. It is very important for us to find cost-effective solutions that are easy to implement and gives a perceived good sound environment. Acouwood is also developing new methods of calculation and prediction of sound insulation in wooden buildings, instead of relying on the traditional “trial and error”-approach.”

-- Germán’s answer: “In our field of work we can take sustainability from the point of view of acoustic comfort, the objective is the sustained well-being of people. Focus on improving productivity and also quality of life. Nowadays companies want buildings with Leed (USA) or Breeam (UK) certifications, or more specifically in personal well-being, we can mention the WELL certification. These certifications take into account sustainability based on improving energy balances both in the use of the building as well as in the footprint left by construction materials in their manufacture. For these requirements, the necessary acoustic comfort is achieved using acoustic solutions from international brands that offer products that contribute positively to certification.”

3. What progress do you think we will achieve in the acoustics sector towards the Sustainable Development Goals 2030 Agenda?

-- Juan’s answer: “I think “we, as acoustic people”, either developers, labs, researchers, manufacturers, consultants, engineers… can contribute to a great extent to the sustainable development goals 2030 agenda. More specifically, I think we have a lot to say and do in the following principles of the agenda, as they are very much related to acoustics:

• 3. Good health and wellbeing (through reducing the high level noise exposure)
• 4. Quality education (good room acoustics has proven to enable quality teaching and learning)
• 7. Affordable and clean energy (in the manufacturing processes, logistics, etc.)
• 9. Industry innovation and infrastructure (in manufacturing processes, logistics, etc.)
• 11. Sustainable cities and communities (products made of recycled materials)
• 12. Responsible consumption and production (in manufacturing processes, logistics, etc.)
• 13. Climate action (in manufacturing processes, logistics, etc.)

All of our actions that we do at Ecophon, particularly (and as our slogan “A sound effect on people” says) are aimed at improving people’s life through providing good room acoustics, and we do it always trying to take good care of our world.”

-- Rikard’s answer: “We are living in an unprecedented time in history where instant, wireless transmission of ideas between humans all around the world, is possible through the internet. By transmitting audio and video, we can now communicate and transfer ideas with people who are analphabets! I believe this is an even greater achievement than the printing press. The ability to read is no longer a gatekeeper to wisdom. I am so over-joyed by this fact, that it brings a tear to my eye just to think about it, because there are far more people who can listen, than who can read. We do not know how far the potential at our fingertips can bring us. This brings us to acoustics. A prerequisite of communication is a good sound environment. It seems to me that good sound quality is more important than good video quality. Just take a quick look at Youtube and see which videos get more views. We acousticians thus have a very, very important work to do. The world will be completely transformed in the coming years, and the change will come quickly.”

-- Germán’s answer: “From here to 2030 I hope that better working conditions will be achieved. Life expectancy is increasing, it is useless to live 10/15 years more without good hearing or health problems derived from noise, the limits of noise levels of occupational exposure are based on studies and projections of more than 50 years ago. I consider it important to rethink the established limits. Noise-induced hearing loss is an occupational disease and in my opinion the current limits can no longer be sustained, I recommend an article by myself. Regarding environmental noise pollution, it has been shown that noise (roads, trains, air traffic, etc.) brings many conditions to citizens, a reference (updated) limit value is given by the WHO, and then each country, as appropriate, emits their own regulations based on that parameter.”

4. From your perspective, how do you thing we should focus on in order to achieve great advancement in a short time? Again looking towards this 10-year period.

- Juan’s answer: “Creating awareness is one of the first steps. Sound cannot be seen nor felt in the same way as we do with, for example, temperature. If one feels warm, he or she opens the window and closes it again once it feels alright again. That is not often possible with noise; we cannot switch between good and bad room acoustic conditions so quickly in our offices, a school of a restaurant. But once acoustic comfort is met and people realise about it, it is highly appreciated.

We are still at the level that many people come home after a day at work or from having dinner at a restaurant, and they don’t realise that the tiredness or headache they have may have been caused by, amid other things, exposure to high levels of noise. Putting acoustics at the same level of awareness of energy, air quality, light… in construction would be a great step.

Regulations are also of paramount importance. Not only norms that state tentative values of different acoustic parameters, but also laws that regulate the compliance with these regulations (both room acoustics and building acoustics). More specifically, in the regulations currently in force regarding room acoustics in Spain (CTE DB HR), the casuistry is fairly limited (nothing stated about hospitals, for example) so that research should be fostered to improve that. Moreover, also the limit levels could be revisited to improve the comfort as well as the introduction of new acoustic descriptors (e.g. some related to intelligibility in schools).”

-- Rikard’s answer: “With regards to wooden constructions, there are plenty of viable technical solutions today. However, we are still witnessing costly mistakes that should not be allowed to occur in 2020. We are talking about well-known acoustic “land-mines”, but apparently, they are not as well-known outside our domain. I like the saying “We need to stop building concrete buildings in wood and start to build wooden buildings”. If one treats sustainable building design as a simple swap of construction materials, mistakes are bound to happen. Sustainable design requires a new way of thinking because we are dealing with a completely different product. I believe that online education is the best tool at our disposal here. One could create free generic acoustic education, presenting the key acoustic concepts with a presentation style adapted to the needs of each technical discipline, e.g. Architechts, Structural engineers, etc. A new business model could then be to include videos in our service, where the critical aspects of each specific project is explained. That way, even the builders on-site could get a quick run-down (on demand) to avoid the acoustic “land-mines”.

Also, the acoustic sector has great potential to evolve better work methods. We are sometimes still using Excel templates from the 1990s in our calculations, with a lot of copy-pasting data. This is not sustainable as there is a high risk of human mistakes and very time-consuming. Implementation of new technology could significantly reduce the required time and increase quality.”

-- Germán’s answer: “With new technologies, for example, the startup denoize (denoize.com) is developing a smart window with noise cancellation. In my opinion noise cancellation is the future, although there are already accessible applications such as headphones, applications (Krisp) and Google Meet is currently about to incorporate background noise cancellation. Physical acoustics, when it comes to materials, is reaching its limit. In 10 years there will be updating of standards based on new technologies. Focus on new conditions and design tailored solutions. New challenges need innovative solutions.”

5. Do you think acoustic comfort awareness has suddenly increased after the outbreak of the Covid-19 pandemic? Apparently the population's sensitivity to noise seems to be increasing after the calm during the quarantines...

- Juan’s answer: “What happened during the lockdown was that noise moved from outdoors (traffic noise, etc.) and the places we work in (office, school…) into our homes. Those who were lucky enough to live in a well-isolated flat or house and/or that had respectful neighbours, realised that one feels much better when living/teleworking exposed to lower noise levels. All of a sudden, the common noise sources at work (people talking, phone ringing, etc.) were no longer present and one can focus better and longer without being distracted, which also can reduce the stress levels and increase performance. However, those who suffered from noisy neighbours in a not-so-well isolated building, or kids running around while trying to work also realised the negative influence noise has on us. All in all, I think it is true that people realised that noise is present in our daily lives and that it can potentially impact negatively our wellbeing. Let’s hope that the great ability we have of forgetting things does not apply to noise awareness.”

-- Rikard’s answer: “There is a saying about a frog that will instantly jump out of boiling water, but if the water is boiled slowly, he will stay in there until death. The same goes for us. We are very good at detecting contrast, but we are lacking in our ability to detect absolute levels. The lockdowns have produced contrast in our way of life, and I do believe that it will result in an increased awareness about acoustics, among other things. For example, I suspect many people who started to work from home came from an open plan office. This change implies a large contrast in ambient noise from conversations, which can significantly reduce productivity for those who are more easily disturbed. But of course, your home must provide adequate acoustics for working, i.e. proper sound insulation from neighbours and external noise, or noise from installations, to get a potential productivity boost. For those who have the possibility, I think it is a good idea to create a proper workspace/room in your home. Covid did not change anything that was already coming, it just accelerated the process of change. With the ongoing urbanization, population density in cities is bound to increase which must lead to higher noise exposures. As a result, I believe that awareness of acoustic comfort will follow.”

-- Germán’s answer: “Noise is a cultural issue, there are noisy and noise tolerant societies and there are more noise sensitive societies. It is true that this pandemic silenced many noises that masked others and today is what is heard. You can hear the church bell, the birds, insects, the sirens of the boats in the distance and obviously the sounds or noises of the neighborhood. Beyond this particularity the trend is clear, greater acoustic comfort went from being a desire to being a necessity and a luxury standard in some cases.”

6. Do you think governments, laws and regulations will keep pace with the demands of committed citizens and a responsible industry?

-- Juan’s answer: “Developed standards are needed in order to fulfil current needs and to improve comfort in buildings (see previous answer in question 4). I think standardisation committees should be active and governments should listed to the experts.”

-- Rikard’s answer: “We are living in a time of accelerating change, and the rate of acceleration is itself accelerating. This is indeed a challenge for the adoption of laws and regulations, which are slow-moving by their very nature. In such an environment, I believe that the wisest thing to do is to focus on the things that we know will not change in ten years. A challenge we often face with acoustic requirements is the “one size fits all” approach. I believe we need to have regulations that are more tailored to the intended usage.”

-- Germán’s answer: “I sincerely hope that the industries take the lead. Don't wait for regulations. I am very optimistic about it. Innovative companies improve working conditions (Google, Facebook). They do not expect regulations. And the results are on sight. They are the most valued in the world. Companies must stop thinking about regulations, and look for comfort for reasons of results. A comfortable worker gives better results.”

So far today's interviews. Once again, thank you very much for your time. It’s been a pleasure talking to you.

[Example Video: Saint-Gobain Ecophon solutions for acoustic conditioning at Ulster Hospital, Innovation and Medical Centre (Ireland). Photographer: Gordon McAvoy]