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Accessibility of smartphones

Due to the digital transformation, the smartphone is becoming increasingly important. 78% of the population in Germany have a smartphone. But how accessible are smartphones? Can everyone really use the small computer in their pocket? The basic prerequisite for usability is the nature of the operating system. We have therefore summarized the most important aspects of the accessibility of the operating software of both market leaders.

A smartphone is a mobile phone combined with computer functionalities. It fulfils the task of a media player, a video camera, a GPS navigation device and a personal digital assistant. Key features are the touch-sensitive screens and the connection to the Internet. Applications for the respective end device can be downloaded via an online shop.

Application (short form: app), means computer program. In today's usage, apps are mostly applications for mobile devices such as smartphones and tablets. Users can obtain apps from the so-called app store, which is integrated in the operating system, and install them directly on the end device. Since apps can be programmed with less effort than earlier computer programs, innovations are constantly coming onto the market.

An operating system is elementary for the use of a smartphone. It consists of a combination of several software systems and forms the interface between hardware and software. The system creates the user interface on which the apps can be managed. An operating system includes the standard applications such as phone, camera, diary, clock, app store and address book.

The operating system determines the layout and the possible functions of the smartphone.

There are five different operating system providers. The most popular systems are iOS and Android.

iOS is the system from Apple. This system is only available on devices from the company. In addition to the iPhone line of smartphones, the tablets, iPad, and iPod touch are also equipped with the system.

Android is the system of the Open Handset Alliance (main member: Google) and is made available on the devices of various manufacturers. Android providers are for example Samsung, HTC, Sony, LG, Huawei, Google and Nokia. Each manufacturer has the possibility to shape and change the layout of the system according to their own ideas.

Less common is the Windows Phone. This is the operating system from Microsoft. The tile model, based on the Windows 8 version for the computer, is offered by HP, Acer, Mircosoft, Toshiba and Nokia. However, due to the negative feedback, the development has been stopped.

In addition, there is also the system of BlackBerry OS and Symbian. These systems are only available on in-house devices of the companies and have a very small user base.

In the following, only the systems of the market leaders will be considered. The accessibility of the other systems is not dealt with.

Apple offers a wide band of operating aids for its users. The company itself divides these into four categories:


In the area of vision, Apple offers a voice over system that works in both its in-house apps and third-party apps. With many settings options, the program can be individualized and made usable for people with vision impairments. In addition, the display and font can be adapted, e.g. enlarged. The smartphone takes over many everyday tasks by reading out screen contents or the dictation function. The integrated personal assistant "Siri" further enhances these functions. Through voice instructions, this can perform various tasks, such as setting an alarm, calling someone, composing and sending messages, or making calendar entries, etc.


For hearing-impaired people, Apple has worked with hearing aid manufacturers to create a link between the hearing aid and the smartphone. If a hearing aid is labeled "made for iPhone", it can be connected to the smartphone via Bluetooth. With additional functions, this offers advantages when making phone calls, listening to music and having conversations in noisy environments. The "Face Time" application has also made it possible for deaf people to make phone calls via video connection, and movies with subtitles can be downloaded from the native store.


The control of the smartphone can be facilitated by Siri or a switch control. With switch control, an external device is connected to the smartphone via Bluetooth. In addition, it is possible to adjust the sensitivity of the touch screen to individual needs.

To reduce difficulties in the area of text input, there is a text recognition and the possibility to connect an external keyboard. The program then recognizes the words as they are written and finishes them independently.

Reading and learning

To facilitate reading on the smartphone, there are three different read aloud functions:

  • read aloud the whole screen
  • read out marked passages
  • individual letters as they are typed into the device

In addition, writing is supported by text recognition. The correct spelling and other words that could be used to continue the sentence are suggested for the written text. An installed dictionary can also explain the meaning of the words.

Google provides the individual smartphone manufacturers with a standard version of Android. In this version, you will find various functions for barrier-free use under the operating aids, which can be subdivided into.

Speech output

The speech output in the Android system is called "TalkBack". This feature provides information about alerts and notifications on the smartphone. TalkBack is activated in the device settings or by pressing both volume buttons for three seconds.

If you only want individual sections or elements to be read aloud or picture elements to be described, there is the "Read aloud" function. By tapping, a single element is selected and by swiping, several objects are selected. If you now press the play button, all selections are read out one after the other. You can pause, play, fast-forward or rewind the reading and adjust the speaking speed.


As an alternative to touchscreen operation, you can also operate the smartphone using external switches, keyboards or mice. These devices are connected to the smartphone via USB cable or wirelessly via Bluetooth. One or more keys on the keyboard can be assigned to an action. With switch control, the individual selection items on the smartphone light up in sequence and are selected by pressing the switch.

Alternatively, a Braille display can be connected via Bluetooth. This can be combined with "TalkBack", which allows texts to be output verbally or in Braille. The smartphone can also be controlled via a Braille display, but only with certain models. To use the function, an app must be downloaded from the store. An overview and instructions can be found on the manufacturer's site.

Screen adjustment

For screen customization, you can change the display, font size, and contrast and color options. The adaptation of the font and display is only applicable from Android 7.0, the color and contrast settings already from version Android 5.0. With a color correction, a red-green vision impairment as well as a blue-yellow vision impairment can be compensated.

To enlarge the screen in the meantime, there are two variants. By tapping the screen three times, the corresponding section is zoomed in. You can now move the zoomed-in window and adjust the zoom level by pulling your fingers together or apart. If you tap three times again, the zoom is ended. Alternatively, zooming can also be selected via the operating aid symbol. Navigation in the zoom window works in the same way.


Subtitles can also be activated. These are individually customizable in language, text size, style, color and background. Voice control is only possible in English so far and is still in the testing process.

For people with a visual impairment, it is particularly important that the voice output can already be activated independently in the settings screen.

On the iPhone, the voice over starts after pressing the home button three times in quick succession. However, the assistant starts in English. In the next step, the desired language must be selected and the Voice Over automatically restarts in the selected language.
However, this method does not apply to the new model iPhone X, because there is no longer a home button.

TalkBack in the Android operating system can also be started in the settings screen. From the operating version 4.1, you press with two fingers simultaneously on the screen until the movement is detected and TalkBack is activated. A tutorial is started automatically.

On older Android systems, you have to draw a closed rectangle on the screen with one finger. When detected, a signal sounds and the voice output is activated.

There are numerous test reports on the Internet about the accessibility of smartphones and tablets. So far, Apple has always been in the lead and scored particularly well with its ease of use, especially for the visually impaired.

But Android is catching up. The big problem with Android, however, is the individualization of the user interfaces for each manufacturer. The designs can be reassembled in shape, color and layout, which means that some pre-installed programs, such as the voice output, cannot capture certain content, making errors possible. It is difficult to determine in advance if this is the case and on which devices. In addition, there is no assurance that all available apps are compatible with accessibility features.

Apple offers a secure availability of operating aids, while Android is often the cheaper alternative. However, a decision in favor of Android may require more effort through research and inquiries with the manufacturer.