Perception And The Elderly – Orfield Labs / Building-performance & Occupancy Research
There are generally two significant ways in which building design can impact occupants. The first area is the science of building-performance; this describes the process of maximizing variables that influence occupants’ perception of comfort such as acoustics, lighting, daylighting, temperature, and indoor air quality. Other variables that affect the perception of comfort in a more peripheral way include human factors and ergonomics.
The second area of impact is occupancy quality, the degree to which different aspects of the building cause its occupants to like or dislike it (occupant preference). This includes variables such as aesthetics, wayfinding (orienting), metaphorical comfort (echoing of other preferred environments), ease of use, etc. Establishing a measure of occupancy quality helps set the baseline regarding current satisfaction and helps to identify which areas of building design (and other factors) are affecting that satisfaction.
Both of these areas are influenced by occupant demographics, and this is particularly difficult to study in elderly populations, as the designer’s experience is often not a good baseline for what the elderly population will experience. While designers are trained to solve problems for most of the population, design for the elderly requires a more advanced view than universal design; design that works for most predictable populations. Designing spaces for the elderly requires consideration of the limitations of non-typical occupants and the needs of average occupants, both the center and the ends of the bell curve of occupant population. In designing these spaces, one of the most difficult issues to control is perceptual noise (background noise, visual glare, thermal discomfort, smells, etc.). This is because the elderly have more difficulty sorting for signal in noise (having a conversation in noise, attempting to see visual tasks in the presence of daylighting glare, etc.)
Elderly Perception
Planning spaces for elderly users, whether they are the core population, such as in a retirement residence, or the limiting elderly population, such as elderly pedestrians, shoppers or church attendees or hospital patients, is more difficult but can be done with a consistent set of standards and approaches. It is difficult because the design team, which normally designs using practice guidelines, intuition and personal experience, is not elderly and has, in many ways, no concept of how older people experience the world and process it. In general, older populations have a narrower range of perception, have lower levels of perceptual sensitivity, are far more sensitive to perceptual noise, and they have slower cognitive processing of these more limited signals. They desire more cognitive and perceptual simplicity.
Auditory Perception – Hearing
For example, a normal 20-year-old may visit a noisy restaurant and notice that it is noisy, but may be fully capable of discriminating between voices within the noise. A 50-year-old may visit the same restaurant and have difficulty hearing the person across the table when the room is noisy. The 70-year-old may have a hearing aid, have no directional hearing (the ability to identify the location of a sound), and thus may not only fail to hear the person across the table, but may hear the person sitting behind them as louder and clearer than the person across the table. This can occur even if the person behind is not speaking any louder. Since the elderly person is neither looking at the person behind them nor communicating with them, and cannot identify that the source of the sound is coming from behind, this becomes a stressful listening and processing situation. This is a confusing and cognitively challenging circumstance that elderly people face on a regular basis, and one that younger people cannot fully appreciate until it occurs to them in their later years.
When one begins to exhibit age-related hearing loss (also called sensory neural hearing loss), there is a loss not only in terms of one’s ability to detect signals, but also in time resolution and frequency resolution. Even when sound is re-amplified through the use of a hearing aid, it still sounds like it is temporally smeared and distorted in frequency. Thus when the family of the hearing-loss patient helps them get a new hearing aid, they don’t understand that this is only a very partial solution, often at a low sound quality, that will requires time for cognitive adaptation to hearing in a new way, both better and worse.
Similarly, while the 20-year-old and 50-year-old may both be able to hear a presentation in a small auditorium, the 70-year-old may find that it is too difficult to focus on the talk due to the greater disruption from background noise and reverberation, in combination with slower and less accurate speech and cognitive processing. This same elderly person will find understanding speech far easier in quiet spaces with low reverberation and low background noise levels. The phenomenon of a medical assistant speaking very loudly into the ear of an older person is fraught with all the inherent mistakes of this misunderstanding. A person with hearing loss can often talk and listen at normal levels is quiet spaces, but he or she needs to hear a louder voice in the presence of other noises. This is not well known to professionals serving the elderly.
Visual Perception – Sight
The elderly population is also at a disadvantage with regard to visual performance. The younger person may sit in a room facing windows with sunlight shining on them, and they may be able to see a person that is talking who is seated on the same wall as the sunlight. Even though the sunlight is bright, their younger perception handles the broad range of brightness values in the presence of sunlight. The 50-year-old will normally move out of the sun, as the brightness range is getting too bright for them to clearly see the face of the talker. The 70-year-old will have to move out of the sun and will still be affected by window brightness, as their ability to see in the presence of bright sunlight is far more limited.
When moving outside at night, the 20-year-old has good night vision and has little difficulty seeing visual images of widely varying ranges of brightness. The 50-year-old is generally already experiencing reduced visual performance, due to brightness sensitivity when walking or driving at night, especially when glare is present. The 70-year old is often disabled by the glare and simply cannot see things that the two younger groups can see. Recently, in Minneapolis, the City installed new pedestrian scale street lighting that was very bright and had no glare or visibility specifications. The police contacted Orfield Labs about their reduced ability to observe suspects, and a meeting was set up with the City Council to demonstrate the experience of the police and the elderly. We explained that the very bright pedestrian scale lighting was discriminating against the elderly, and even into the range of 40-50 year old officers. After demonstrating this phenomenon, the City authorized a study and a set of recommendations to insure that older people would see better, not worse, under future pedestrian scale lighting.
Olfactory Perception – Smell
In a similar way, the sense of smell is reduced in range and sensitivity, and its processing is slower and less sensitive. Thus, the cues to danger, such as the smell of fire or of something burning in the kitchen, are very difficult to detect, and the olfactory cues to taste, based on smell, are often dramatically reduced, thereby reducing the pleasure of a good meal.
Taste Perception – Taste
Taste perception accounts for similar losses, and one particular loss that has been found to be pronounced is the loss of perception of the taste of animal fat in food, one of the most highly desirable tastes for many people. A recent medical research article in the Wall Street Journal suggested that the elderly have about 1/20th the perception of animal fat from food as younger diners. This is thought to be the reason that the elderly are fonder of higher fat foods. In order to detect tastes at the same intensity as they did when they were younger, they need to have a dramatically higher dose of fat. Thus, while it is commonly believed that a bland diet is suitable for the elderly, there is good evidence that this conclusion is very specifically wrong, and that healthy, higher flavor foods, like citrus fruits, are often strongly preferred by older persons.
Thermal Perception – Feeling of Hot and Cold
The perception of thermal comfort, and the basis of thermal comfort theory, is that activity rates, clothing, humidity and radiant asymmetry (vertical or horizontal disparities in thermal radiation) play a large part in achieving desired thermal comfort. Yet the elderly have very limited activity rates in most cases, and they therefore desire a thermal comfort condition that provides better support for warmth in a sedentary population.
Conversely, the thermal comfort theory argues that more physical activity better supports thermal comfort in typical environments. Older persons with higher activity rates are generally a bit more comfortable at normal temperatures.
And while heating and cooling distribution are generally from the ceiling, the elderly are most commonly found in the seated floor zone, where this distribution is often least efficient in providing thermal balance.
Strength & Balance – Physiology & Kinesthesia
Much of this same research suggests that bodily agility is a function of exercise, and that strength, balance, orientation, etc. can be maintained as physical capabilities. About 10 years ago, there was a classic Norwegian study about physically limited and non-ambulatory populations of 90 year olds living at home. While medical research, at that time, believed that muscle mass could not be increased due to exercises in the 90’s, this population was put on a weight training program, and after six months, most became ambulatory, and the average muscle mass level increase was 30%, an amazing result. This has clear implications for elderly populations, as lack of agility, strength and balance are the number one reason for permanently disabling injuries, such as falls.
Cross Modal (Multi-Sensory) Influences
All populations are affected by perceptual complexity. It is easy to test this by pinching oneself while taking a warm turbulent shower. The “noise” of the hot water pounding on the skin reduces the perception of pain, as the body is ‘perceptually loaded’ with water stimuli. It is equally true that in noisy environments, our visual detection reduces, for this same reason of perceptual loading. The consequence of this for the elderly is the reduced ability to process signals in noise, no matter in what perceptual channel the signal arises (sight, sound, taste, etc). Therefore, controlling the perceptual complexity of the environment requires consideration of all kinds of perceptual ‘noise’.
Religious Architecture
Religious architecture is often a touch- stone with the elderly, as they often move toward their early faith traditions as they age. Worship spaces are thus often preferred environments that many elderly chose to visit.
Having designed hundreds of worship spaces, we often tell the priest, minister, or rabbi that there is an inverse relation- ship between hearing, seeing, and giving. If the elderly cannot listen, see and understand successfully in their worship space, they will often leave rather than complain, and the younger generation, with more robust perceptual skills, (and with minimal financial contributions), will remain. It is a common story in churches that about 5% of the congregation provides the majority of the financial support, and most of them are in the older ranges of the congregation.
Many church committees suggest a lack of complaints, but this is not at all conclusive of poor hearing or seeing. In order to determine the value of the space to the elderly, you actually have to test the older population and have them repeat what they have seen or heard, because elderly persons are far less inclined to complain or to highlight their age-related disabilities. Thus, not considering the elderly is often a case of failure of both community and economic missions for the organization serving this population.
A Perspective on Aging in Environments
Much as we don’t penalize our young children for their failure to track our thoughts and discussions, we must equally honor our elderly and accept that they, like our very young children, are often having a very different experience than we are in the same place and at the same time. We must work very hard to better understand age-related experiences in much the same way as we understand persons suffering from physical and mental disabilities. In most cases, the elderly are mentally sharp, have good senses of humor and are nice people, like the rest of us. But they are dealing through a set of perceptual and cognitive processing filters that we must begin to understand, if we are not to penalize them for simply being older. Often, wisdom comes with age, and equally, having more understanding about age-related limits allows the elderly to function more within their wisdom mode and less within the confines and fears of their deficits.
Steve Orfield is founder and president of Orfield Laboratories, Inc. Minneapolis, MN. He can be reached at steve@orfieldlabs.com, T: 612.721.2455. Orfield Laboratories, Inc. is a multi-disciplinary laboratory serving North American and international clients and provides services in Acoustics, Vibration, Vision, Lighting, Architecture and Market Research.