How blind people orient themselves

Rough contact with walls, cars or tables is part of everyday life for blind people. Running through the city is like Tetris and Pakman rolled into one. For the sighted person, the space consists of free areas that are bordered by objects. For the blind person it consists of objects between which there is free space.

A World created for Sighted

For blind people, the world is an often stressful collection of obstacles. There's a garbage container in the way, there's a barrier set up for a construction site, and somewhere else the rear-view mirror of a truck hangs at head height. In the pedestrian zone, a passer-by, a cyclist and a car approach from different directions. The fact that they still get through life relatively accident-free is nothing short of a miracle.

Blind people use all remaining senses to orient themselves. Anyone who focuses too much on the sense of sight overlooks the fact that many senses are used passively. We can smell the bakery or the restaurant from a greater distance, we can hear the traffic in the distance in the city park, and if the ground conditions suddenly change, we notice it immediately.

Although tactile contact via hands and feet is probably the most important thing for most blind people, orientation is much more difficult without hearing, smell and other sensory stimuli. For example, we can tell whether we are approaching a building based on the direction of the wind. Wind can only blow towards us over an open area. Therefore, the direction the wind is coming from is probably not a building or a hill. When I walk through Bonn's Rheinaue, I orientate myself by the position of the sun. I base my efforts on the time of day, in the morning the sun shines from the direction of the B9, so if I want to get out of the park I have to walk in that direction. In addition, I also orient myself to the traffic noise of a highway. Others may be bothered by this, I wouldn't go to the park if there weren't traffic because I would quickly lose my bearings on the winding paths.

Hearing plays a significant role. Many landscapes have their own unique sound. I'm currently sitting on a bench at Poppelsdorfer Platz and can hear how numerous buses stop at the stops, the characteristic silence when the cars on the main street have to stop because of a green traffic light and the way the sound is reflected from the buildings. that are typical of this place. I can't say I would recognize this place if I didn't know where I was. But I could blindly say where I am on Poppelsdorfer Platz.

For those who see it, every landscape has a typical appearance. For the blind, every place can have a typical sound image. This sound image is formed from thousands of factors: the traffic on the road, the way the sound reflects off the walls, the sound of feet on the floor and much more. In other countries, smells can play a similar role. I was at an Indian spice market a few years ago. The penetrating scent of so many spices is an incomparable, not necessarily pleasant, olfactory experience. The advantage for blind people is that they can orient themselves even better thanks to such smells. In his book Seeing in the Dark, John Hull described how the rain created a soundscape in his head: Rain on paving stones sounds different than on grass or trees.

You only realize how important your hearing is when it fails. The signals from acoustic traffic lights are often overshadowed by traffic noise. A jackhammer cuts a blind man off from all other noise. I always feel uncomfortable when I no longer have acoustic contact with the environment and avoid construction sites if possible.

The haptics, i.e. the physical contact with the environment, should of course not be neglected. Blind people - like sighted people - mostly use the same paths and thereby develop a memory for the nature of the ground and solid obstacles such as lampposts. Robert-Schuman-Platz in Bonn, for example, is tiled in some places, paved in some places and smooth as a sidewalk in many places. Blind people therefore know very well how to cross the square in such a way that they reach the desired destination. Small walls that are supposed to serve as boundaries for the cars also are helpful.

Such obstacles play a major role in orientation. Many blind people specifically look for boundaries in the form of walls, meadows or curbs in order to be able to locate their own position and orient themselves accordingly. Therefore, in addition to winding paths, large open spaces are a big challenge for blind people. If they have to deviate slightly from their route because of a construction site or a market stall, they can lose their way completely. Open areas such as large meadows or fields are very difficult terrain for blind people.

Both sighted and blind people create a mental representation of the environment in their heads. Imagine the building where you live or work. Especially at your workplace, there will be rooms that you have never entered. Nevertheless, you have a mental image of the building and, for example, you know where a room is if someone describes the way to it. Blind people form a similar representation, although this representation only includes the part of the space that is relevant to them. For example, they know that after three steps there will be a post in the way - what it is for doesn't matter to them. If you walk ten meters along until you come to a loose floor slab and turn to the left, there is a mailbox there. When they come across the beginning of a grassy area, they turn 40 degrees to get to the entrance of the building. That's why it's usually not a problem for blind people if they collide with a wall or something else. You need these boundaries in order to be able to determine your own position. Imagine you were standing in an open space blindfolded and wanted to go to a certain place, how would you do that? Even if someone pushes you in the right direction, it only takes one odd step and you might run a meter, maybe ten meters past your goal. Blind people do not know what the ceiling of a room or other areas that they cannot reach look like. But it doesn't matter to them either.

Near and far orientation

Two forms of orientation can be distinguished. Close-up orientation is primarily about avoiding obstacles or finding prominent objects such as house entrances. Long-distance orientation is about moving in large areas: this could be walking from home to work, walking through the park or finding a room in a large building.

Different skills are required. When it comes to close-up orientation, good cane technique is particularly important. The blind person must be able to avoid obstacles. Long-distance orientation is all about remembering paths and finding them again. The orientation works in many ways. The blind person integrates acoustic and tactile stimuli, but also smells, into his image, as well as other stimuli such as the warmth of the sun or a draft. Not only does he have to manage to find a certain place, he usually also has to find his way back, for example to the bus stop. Foreign paths are much more difficult for a blind person than for a sighted person.

Orientation and mobility training

There is the so-called orientation and mobility training for blind people. Specialized rehabilitation teachers teach the blind people basic orientation techniques and how to use the blind cane correctly.

You have to be aware that our world is not designed for blind people to find their way around. While sighted people learn the basic traffic rules at school or through observation, blind people have to be actively taught. Until a few years ago, I didn't know that cars had the right of way in zebra crossings. I thought a crosswalk was some kind of evergreen traffic light for pedestrians.

Question: How does a blind person cross the typical X-intersection? This is actually relatively simple. He waits for traffic to move on the street he doesn't want to cross; if cars are on one street, those on the other have to wait and vice versa. Of course, this only works for simple intersections. There are also complex intersections that are difficult for blind people to cross sensibly and safely. I prefer a clearer intersection and therefore often take long detours.

What I just described is the basic training. Another form of training is exploring new paths. A blind person should be able to get to and from work or go shopping on their own. The mobility teachers practice important routes with him, show him orientation points or how to navigate difficult places, such as. B. train rails, can be crossed safely.

The blind person must first learn close orientation before he can learn orientation on important paths. When he moves to a new city, he gets the long-distance orientationtaught again. It is important that he gets a basic understanding of where he lives, because the bigger a city is, the less he will be able to be taught all the necessary ways. Even a medium-sized city like Bonn is difficult to survey. Berlin would be beyond any mobility training. No one could remember so many routes if they didn't use them regularly. In such situations, it is more important to roughly know the layout of the districts, understand the logic of public transport and, if necessary, get further information via Google Maps.

The blind cane

The blind cane, or more correctly expressed blind long cane, is a white stick for touching or rolling. It is the most important orientation and identification aid for blind people. The blind person uses the stick to scan an area about one and a half steps in front of him. The stick is swung at shoulder width because the shoulders are the widest part of the body. The cane can very reliably detect obstacles on the ground and at a height of around one meter, including steps, flower pots, people and anything else that stands in the way. Because it is held at a certain angle, it cannot detect obstacles that are above the belly button. Blind people are therefore poorly protected, especially against head injuries. The blind cane is white so that it can be easily recognized by the sighted. It is designed so that it reflects light from lamps or car headlight.

The constant noise when typing and scrolling gets on many people's nerves, but it has some important functions. The first non-verbal message is: “Attention, I’m coming.” The blind person receives attention from sighted people who can avoid him or warn him. The noise also serves for indirect orientation; the sound is reflected by the environment and thus provides information about how far you are from a wall or whether the path in front of you is clear.

You can often read in the media that this or that development will make the cane superfluous. This is not the case for most blind people. Hardly any blind person will voluntarily forego having further tactile contact with the environment beyond their feet and hands. Devices break, batteries can run out, but the blind cane is relatively robust. In addition, as already mentioned, it is also a signal to other people that cannot be replaced by anything.

The guide dog

The guide dog for the blind is a trained assistance dog. There are special schools where these dogs are prepared for their task.

The dog is harnessed into a harness that allows the blind man to recognize every movement of the dog via a bracket that he holds in his hand. The dog is trained to recognize obstacles for itself and its owner and to avoid them or stop when danger threatens.

The guide dog learns to recognize dangers not only for itself, but also for the person it is leading. He can learn paths to travel regularly and find certain objects such as doors or stairs if he has been taught to do so. However, it is not a navigation system, so it is necessary for blind people to be able to orient themselves independently, especially on new paths.

Although dogs learn to obey their master's commands, they should also be able to disobey a command when danger threatens. This is called intelligent disobedience. In dangerous situations, the dog has to decide what makes the most sense: keep walking, avoid it or stand still. This is important, for example, for deaf-blind people who have considerable difficulty perceiving their surroundings due to two missing senses.

Many guide dogs for the blind are Labradors or Golden Retrievers. There are also German Shepherds and, more rarely, Border Collies or Royal Poodles. Labradors are preferred because they are curious, helpful and very open to new experiences. The everyday demands on a guide dog are very high, which is why it has to be extremely hard-working and resilient.

Click Sonar

Click sonar, also known as echolocation, is a technique that mimics the natural ability of some animals, such as bats and dolphins, to navigate and perceive their environment using sound waves. In the context of assistive technology for the blind, click sonar involves emitting brief, high-frequency sounds, often in the form of clicks or pulses, and interpreting the echoes that bounce back from objects in the environment.

Click sonar devices typically consist of a portable unit equipped with sensors and an auditory feedback system. When activated, the device emits sound pulses, which travel outward and bounce off nearby objects. The device then detects the returning echoes and translates them into auditory signals, such as varying tones or patterns of clicks. Users can interpret these signals to gauge the distance, size, and location of objects around them, enabling them to navigate safely and independently.

Click sonar technology has a wide range of applications beyond personal navigation devices. It can be integrated into mobility aids such as canes or guide dogs' harnesses, enabling seamless integration into users' daily routines. Additionally, click sonar systems can be incorporated into smart devices and wearable technology, offering real-time feedback and personalized assistance based on users' specific needs and preferences.