Dedicated video phones and PC multi-media systems offer the possibility of communicating visually. This would allow objects and text to be shown visually, as well as allow signing to a deaf person through video interpreting.
With more elderly people living alone, a simple to use video phone can provide greater security and independence. Research in Sweden has shown that video phones can be very useful for someone with an intellectual impairment.
Mobile video telephony is now also available on several handsets.
What is a video phone?
A video phone is a telephone with a viewing screen and a built-in camera, and is capable of full duplex (bi-directional), video and audio transmissions for communication between people in real-time.
Video phone calls differ from videoconferencing in that they expect to serve individuals, not groups. However, that distinction is becoming increasingly blurred with technology improvements such as increased bandwidth, which can allow for multiple parties on a call.
Video interpreting services are also known as Video Remote Interpreting (VRI), it is where a deaf person and hearing person are sitting beside each other in the same place and the interpreter is in another place interpreting for them through a video phone.
With the advance of new third generation (3G) technologies such as UMTS (Universal Mobile Telecommunications System), mobile video telephony is available on a large (and growing), number of handsets.
By pressing a number (or selecting a contact from the address book), a user can opt to dial a video call instead of a regular voice call.
Problems encountered by disabled people and the ageing population using video phones
Potential accessibility barriers include:
People with visual impairments may face problems reading from the screen if they are unable to increase the type size.
They may also be unable to define the line status if just relying on a visual indicator.
Hearing impaired users may not be able to hear the ringer or identify the line status.
They may also be prevented to communicate via lip reading or sign language, which requires at least 25 frames per second, if the bandwidth is low and processing levels are poor.
Physical problems (e.g. weak grip and hand tremors), can make lifting the handset and accessing buttons difficult.
Those with head and neck problems or those in a wheelchair may have problems seeing the screen.
People with an intellectual impairment may have difficulties understanding the functions of a video phone.
Some members of the ageing population can often experience a range of difficulties with video phones, such as those stated above: from not hearing the telephone ring; being unable to pick the handset up, not seeing the screen very well and the incompatibility with a hearing aid.
Possible recommended features include:
- Higher bandwidth and better processing will permit lip reading as well as sign language communication
- Good lighting and contrast between the person and a plain background can improve visual clutter; this is particularly important for reading sign language
- Phone should be ergonomically designed
- General layout of the phone should be standardised and functions should be easy to understand
- Menu systems should be helpful and logical
- Good contrast should be provided i.e. for text, graphics
- Provision for adequate and adjustable illumination of the display whenever possible
- A large tilting display makes it easier to see the picture clearly and can reduce the glare from lights
- Anti-glare provision to avoid reflections whenever possible
- A line by line presentation is often preferable to a single line of scrolling text
- Combinations of blue, green and violet should be avoided
- Colour alone should not carry information
- Visual indication of line status is available
- Visual indicator for ringer, or a socket for external flashing light
- A keyboard will permit the addition of text messages which can be particularly useful for deaf persons
- Good visual contrast between the keys and the body of the phone
- Key tops should be convex or flat with a raised edge
- Keys should be as large as possible without reducing the distance between the keys to less than half the key width
- Ideally the keys should be internally illuminated, but the internal illumination should not reduce the legibility of the numbers in daylight
- The visual markings on the keys should be of high contrast, clear and as large as possible on the key top
- Keys should be raised above the body of the phone (preferably by 5 mm)
- Auditory and tactual feedback of key activation
- Tactual indication on the '5' key or on a QWERTY keyboard on the 'F' and 'J' keys
- A voice mode selection that announces all key presses
- Key functions that are easy to understand
- Fonts should be clear, have a minimum size of 12 point, with high contrast backgrounds
- There is clear letter spacing between each character
- Kerning between specific characters is sufficient so as to ensure legibility
- Avoid the use of italic fonts as they are more difficult and slower to read
- Avoid patterned backgrounds for fonts
- Ensure the font has both upper and lower case letters as it is easier to read text in upper and lower case than all capital letters
- Ability to select larger text
- Information should be presented in small amounts which can be easily retained
- There is the ability to select special volume settings
- Sound indication of line status is available
- High audio quality
- There is an option to switch off verbal feedback when/if not required
- There is an option to switch off non-speech sounds, if used
- Voice warnings should be presented in a voice that is different from other voices that will be heard in the task situation
- Maximise the intelligibility of the messages
- Make the voice as natural as possible so people are more likely to accept it
- If the message is missed, it is beneficial for people to be able to replay it
- If the message is familiar, the ability to interrupt the message would be beneficial for experienced users
- Where the choice of messages is relatively limited, human voices are preferred because synthetic speech is less intelligible and less preferred
- Use non-speech audio messages only for the purposes of alerting
- ETSI ES 201 275 (1998) Human Factors (HF); User control procedures in basic call, point-to-point connections, for Integrated Services Digital Network (ISDN) videotelephony
- ETSI ETS 300 375 (November 1994) Pictograms for point to point videotelephony
- ETSI TR 101 806 (2000) Human Factors: Guidelines for telecommunications relay services for text and video
- ISO/CD 24500 Guidelines for all people, including elderly persons and persons with disabilities - Auditory signals on consumer products
- ISO / IEC 24755 (2007) Information technology - Screen icons and symbols for personal mobile communication devices
- ITU-T E.161 (2001) Arrangements of digits, letters and symbols on telephones and other devices that can be used for gaining access to a telephone network
- ITU-T F.724 (2005) Service description and requirements for videotelephony services over IP networks
- ITU-T F.790 (2007) Telecommunications accessibility guidelines for older persons and persons with disabilities
- ITU-T H Supplement 1 (1999) Application profile - Sign language and lip-reading real-time conversation using low bit-rate video communication
- Gill, J. M. & Shipley, A. D. C. (1999) Telephones - What features do disabled people need? [accessed 12/03/09]
- Kyle, J. (2004) Video telephony and video information for deaf people. Proceedings of the Conference on The Use of Broadband by Older People and People with Disabilities, UK, 24 November 2004. London: PhoneAbility. [accessed 12/03/09]
- Nordic Forum for Telecommunication and Disability (2002) Nordic Guide to Video Telephony and Video Relay Service - for persons with impairments (PDF). [accessed 12/03/09]
- Plain Old Telephone System (POTS)
- RNID (n.d.) Video communications (factsheet). [accessed 12/03/09]
- Voice over Internet Protocol (VoIP)