Accessibility of Virtual Reality Environments

Overview

  • Virtual reality replaces the real world with a virtual environment created by software. e.g. Oculus Rift, HTC vive, Google cardboard
  • Augmented reality supplements the real world with virtual objects. e.g. Microsoft Hololens, Google Glass
  • Virtual reality has had mixed reviews from users with disabilities
  • Pro: Allows users to experience situations that they cannot control in real life
  • Pro: Can offers improved spatial awareness and hand/eye coordination
  • Pro: Lends itself to peer mentoring for those requiring assistance
  • Pro: Virtual reality is perceived favorably by the public, particularly when linked to theraputic outcomes 7
  • Con: Virtual reality has a lot of blue-sky thinking associated with it. Viewing virtual reality as a 'cure' for disability raises a number of ethical considerations
  • Con: Users who experience difficulties may choose abandon virtual experiences rather than seek assistance
Students taking a virtual fieldtrip using Google cardboard
Students taking a virtual fieldtrip. Photo credit: Barrett Web Coordinator

Mobility

  • Pro: Virtual environments can offer users the ability to overcome real world physical barriers
  • Pro: Avatars allows users to customise how they present themselves to others. Some users choose an avatar with a wheelchair, others do not: some switch between avatars with and without mobility aids 1
  • Con: Interaction in virtual environments often involves precise click targets
  • Con: Users with mobility impairments may have difficulty using input devices such as motion controllers
  • Con: Users with mobility impairments may have difficulty using head trackers to adjust roll, pitch and yaw
  • Con: Users with severe mobility impairments may find locomotion, such as walking or flying, difficult
  • Con: Users may have difficulty sensing haptic cues
Examples of Haptic Cues 5
CueAmbientObjectMovementInformational
Tactile Atmospheric Wind, Factory-floor vibration Air-conditioning airflow, Air-conditioning vibration Movement wind, footstep vibration Directional wind, proximity alert vibration
Kinesthetic N/A Force feedback for object collisions Arm swing Force feedback from joystick

Mobility Use Cases

  • As a user with a mobility impairment, I need to be able to adjust time limits, so I can complete tasks.
  • As a user with a mobility impairment, I need to use multiple input devices, so that I can interact with the environment.
  • As a user with a mobility impairment, I need a focus indicator, so I can identify which element has focus.
A wheelchair being used as an input device for a virtual environment
A wheelchair being used as an input device. Image courtesy of Tim Lupo

Hearing

  • Pro: To date VR has focussed mainly on the visual aspects of virtual reality
  • Con: Some virtual experiences rely heavily on audible cues to guide users
  • Con: Bluetooth latency impacts upon the ability of users to perceive visual and audio events synchronously
  • Con: Users may not be able to communicate using voice chat
  • Con: Audio dialog requires captions
  • Con: Sign language is not supported
Examples of Auditory Cues 5
AmbientObjectMovementInformational
City street noise Air-conditioning hum Footstep sounds Audio instructions

Hearing Use Cases

  • As a user with a hearing impairment, I need to be able to turn off ambient soundscapes, so I can hear interface elements such as clicks, bleeps and transitions.
  • As a user with a hearing impairment, I need visual or haptic equivalents of aural interfaces, so I can interact with interface elements.
  • As a user who hears better in one ear, I need to be able to control the location of spatialized audio, so I can hear interface elements.
  • As a user with a hearing impairment, I need captions of dialog, so I can read what is being said.
Sign language speaker being recorded on a tablet
Phoebe Kaplan films Maggie Bork as she signs an American Sign Language poem. The video was incorporated into a virtual reality mobile application. Photo courtesy of UNCG.

Cognition

  • Pro: If given training and time to learn, users with cognitive impairments can become proficient in virtual environments 1
  • Pro: The vividness and synchronous interaction of virtual environments can allow users to focus their attention more effectively
  • Pro: Can allow users with Asperger's Syndrome to learn social skills that might be difficult to grasp in real life 1
  • Pro: Students who need more training and time can usually replicate learning artefacts and interactions
  • Pro: Virtual environments can be designed to support error-free training, which can assist cognitive disorders 7
  • Pro: The distratction offered by Immersive Virtual Reality (IVR) has the potential to diminish pain perception amongst chronic and acute pain sufferers 8
  • Con: The user interface may be difficult to learn
  • Con: Virtual world skills may be difficult to acquire
  • Con: Input devices such as wands, joysticks and 3D mice may be difficult to master 7
  • Con: Some users may experience vertigo
  • Con: Users may suffer from motion sickness, due to conflicts between sensory cues or between the virtual environment and what is felt be the body 7
  • Con: Users may experience disturbed motor skills after using virtual environments, due to a lag in readaptation to the real world environment 7
  • Con: Flashing or moving objects may cause seizures or migraines 1

Cognition Use Cases

  • As a user with a photosensitive seizure disorder, I need to avoid three flashes in a second, so I do not have a seizure.
  • As a user with a cognitive impairment, I need training and time, so that I can learn the environment.
  • As a user with a disability, I need suggestions on how to fix input errors, so I can easily correct mistakes.
VR spatial rotation exercise being used to test cognition
VR spatial rotation exercise being used to test cognition. Image courtesy of Ye Pan, UCL

Low Vision

  • Pro: Voice chat can be useful
  • Con: Users may have difficulty identifying objects
  • Con: Users may have difficulty perceiving events
  • Con: Users need to be able to change the text size of the interface and chat windows
  • Con: Users may have trouble reading text which lacks sufficient contrast against the background

Low Vision Use Cases

  • As a user with low vision, I need to be able to increase text size, so I can read without a screen magnifier.
  • As a user with low vision, I need to have sufficient contrast between text and the background, so I can read the text.
Simulation of a virual environment as seen by a user with low vision
Simulation of a virual environment (left) as seen by a user with a vision impairment (right). Original image: Kylie_Jaxxon

Blindness

  • Pro: Haptic feedback an alternate means of feedback to users
  • Pro: Organisations such as the Web3D Consortium are trying to develop open standards, such as X3D, so that 3D web-based graphics can be intergrated with HTML
  • Pro: Mobility and orientation activities in virtual environments can transer to real environments 4
  • Pro: Sensory substitution devices (SSDs), such as vitual canes and visual to music converters, can be used to aid virtual mobility and perception of shapes and colors 4
  • Con: Most content of virtual environments is heavily visual
  • Con: VR platforms are not designed to work with screen readers such as JAWS or NVDA
  • Con: Don't use the usual accessibility APIs
  • Con: There is no accepted metadata standard virtual worlds
  • Con: Developers do not have access to information for understanding the needs of vision impaired users, or accepted techniques for resolving issues
  • Con: Whilst many of the use cases for VR are similar to the web, there are no accessibility guidelines such as alternative text and meta information for objects
Examples of Visual Cues 5
AmbientObjectMovementInformational
Environmental light Buildings, tools Visual flow Information panel, virtual compass

Blindness Use Cases

  • As a user with no vision, I need verbal descriptions of interactions, objects and locations, so I can navigate.
Photo of haptic glove connected to a laptop showing a virtual hand on screen
Haptic glove being used for virtual interaction. Photo credit: pennstatenews

Olfactory

  • Pro: For the most part, users who have difficulty perceiving odours will have little difficutly interacting with virtual environments
  • Pro: Many olfactory cues, such as the smell of a burning pot in a cooking activity, can be represented visually, e.g. smoke coming from a pot
  • Con: Smell is likely to be an important part of Immersive Virtual Reality (IVR)
Examples of Olfactory Cues 5
AmbientObjectMovementInformational
Smell of the Sea Fruit smell N/A Rosemary indicating color

Olfactory Use Cases

  • As a user who cannot who has difficulty perceiving odours, I need a visual equivalents, so I can perceive olfactory events.

Older Users

  • Pro: Rehabilitation activities for stroke in virtual environments can translate to real world outcomes 7
  • Pro: Gaming features in virtual environments can enhance motivation of stroke sufferers undergoing therapy
  • Pro: VR lends itself to home based rehabilitation

Use Cases of Older Users

  • As an older user I need training and time, so that I can learn the environment.

Issues for Academics

  • How do we define the learning outcomes of virtual reality interactions?
  • How do we evaluate the success of virtual world interactions?

References

Contact Us

For assistance or to report accessibility problems please contact:

Andrew Normand
Web Accessibility Lead
Email: anormand@unimelb.edu.au
Phone: +61 3 9035 4867