Accessibility of smartphones

Due to the digital change, the smartphone is becoming more and more important. 78% of the population in Germany have a smartphone. But how barrier-free are smartphones? Can really everyone operate the small computer for their pocket? The basic prerequisite for operability is the nature of the operating system. That's why we have 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 performs the functions of a media player, a video camera, a GPS navigation device and a personal digital assistant. Central 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 language, 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 programs such as telephone, camera, calendar, time, app store and address book.

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

There are five different providers of operating systems. The best known systems are iOS and Android.

iOS is the system from Apple. This system is only available on company devices. Besides the smartphone series iPhone, 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 available on devices of various manufacturers. Android providers include Samsung, HTC, Sony, LG, Huawei, Google and Nokia. Every 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 was stopped.

In addition, there is the system of BlackBerry OS and Symbian. These systems are only available on the companies' own devices and have only a very small number of users.

In the following, only the systems of the market leaders are considered. The accessibility of the other systems is not discussed.

Apple offers a wide range of accessibility features 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 in-house apps and third-party apps. A wide range of settings allows you to customize the application and make it useful for people with visual impairments. In addition, the display and font can be adjusted, e.g. enlarged. The smartphone can perform many everyday tasks by reading aloud screen contents or dictating. The integrated personal assistant "Siri" further enhances these functions. With voice instructions, it can perform various tasks, such as setting an alarm clock, calling someone, writing 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 marked "made for iPhone", it can be connected to the smartphone via Bluetooth. With additional features, this offers advantages when making phone calls, listening to music and conversations in noisy environments. The "Face Time" program has also made it possible for deaf people to make phone calls via video connection, and films with subtitles can be downloaded from the system's own store.


The control of the smartphone can be made easier by Siri or a switch control. With switch control, an external device is connected to the smartphone via Bluetooth. It is also possible to adjust the sensitivity of the touch screen to individual needs.

To reduce difficulties in entering text, there is text recognition and the possibility of connecting an external keyboard. The program then recognizes the words as you type and automatically terminates them.

Reading and learning

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

  • read out the whole screen
  • read marked positions
  • individual letters when entering the device

Writing is also supported by text recognition. For the written text, the correct spelling and other words with which the sentence could continue are suggested. An installed dictionary can also explain the meaning of the words.

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

Voice output

The voice output in the Android system is called "TalkBack". This function informs about warnings 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 to have individual sections or elements read aloud or image elements described, there is the "Read aloud" function. A single element is selected by tapping and several objects are selected by deleting them. If you now press the play button, all markings are read out one after the other. You can pause, play, fast-forward or rewind the reading aloud and adjust the speaking speed.


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

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

Screen adjustment

For an individual adaptation of the screen, the display, font size, contrast and colour options can be changed. The adjustment of the font and display is only applicable from Android 7.0 on, the color and contrast settings already from Android 5.0. In a color correction, a red-green vision weakness as well as a blue-yellow vision weakness can be compensated.

There are two ways to enlarge the screen in the meantime. Tap the screen three times to enlarge the corresponding section. You can now move the zoomed-in window and adjust the zoom level by contracting or expanding the fingers. By tapping three times again, the zoom is stopped again. Alternatively, the zooming can also be selected through the help icon. Navigation in the zoom window works in the same way.


In addition, subtitles can also be activated. These can be customized in language, text size, style, color and background. Voice control is currently only available in English and is still being tested.

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

On iPhone, voice over starts after you press the Home button three times in quick succession. However, the assistant starts in English. The next step is to select your preferred language and the voice over will automatically restart in the selected language.
This method does not apply to the new iPhone X model, however, because it no longer has a Home button.

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

With older Android systems you have to drag a closed rectangle on the screen with one finger. If the system recognizes it, a signal sounds and the voice output is activated.

There are numerous test reports on the Internet on the subject of accessibility of smartphones and tablets. Up to now Apple has always been ahead and was able to score especially because of its ease of use, especially for the visually impaired.

But Android is catching up. The big problem with Android, however, is the individualisation of user interfaces for the individual manufacturers. The designs can be recomposed in form, colour and arrangement, which means that some pre-installed programs, such as voice output, cannot capture certain content and therefore errors are possible. It is difficult to determine in advance whether this is the case, and if so, which devices are affected. In addition, it is not guaranteed that all available apps are compatible with the operating aids.

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