EN 301 549 Clause 6 - 8 Overview
Published
Here is my summary of EN 301 549 Clauses 6, 7, and 8
Clause 6: ICT with two-way voice communication
This clause focuses on accessibility requirements for ICT that enables two or more people to communicate using their voices, such as door entry phones or digital meeting systems. It includes specific requirements for various aspects of two-way voice communication:
- Audio Bandwidth for Speech: The ICT must be able to encode and decode two-way voice communication with a frequency range having an upper limit of at least 7000 Hz, which is crucial for good audio quality, especially for users with hearing impairments
- Real-Time Text (RTT) Functionality
- If two-way voice communication is provided, the ICT must also offer a means for two-way RTT communication, RTT is text that's sent instantly as it is typed, similar to a chat function. This can be provided by default or added later, potentially requiring additional hardware or software.
- The ICT should allow users to simultaneously use voice and RTT through a single connection.
- Displayed sent text must be visually differentiated and separated from received text. The send/receive direction of text must be programmatically determinable (unless closed functionality), to let screen readers to distinguish between incoming and outgoing text.
- Speaker identification for voice users should also be provided for RTT.
- A real-time visual indicator of audio activity on the display is required to inform users who cannot hear when someone is speaking.
- RTT input must be transmitted to the network or platform with minimal delay, ideally less than 500 ms, for a continuous communication experience.
- RTT is particular for users who cannot hear or speak
- Caller Identification: If the ICT provides caller identification or similar telecommunications functions, this information must be available in text form and be programmatically determinable, unless the functionality is closed.
- Alternatives to Voice-Based Services: For real-time voice-based communication (e.g., voicemail, auto-attendant), the ICT must offer alternatives that allow users to access information and perform tasks without needing to hear or speak. A combination of audio, real-time text, and video can meet this requirement.
- Video Communication: This section includes requirements for users who rely on sign language or lip-reading, such as supporting QVGA resolution (320 x 240) and a frame rate of at least 20 Frames Per Second (FPS). There should be a maximum time difference of 100 ms between speech audio and video. A visual indicator of audio activity and speaker identification for sign language users are also required.
- Alternatives to Video-Based Services: If real-time video-based communication is provided, alternatives must allow users to access information and performtasks without vision, hearing, or speech, as applicable
Clause 6 User Group
- Clause 6 is primiarly for users without hearing (WH), those with limited hearing (LH) and users without vocal capabilities (WC)
Clause 7: ICT with video capabilities
This clause focuses on making video content accessible. Key aspects include:
- Captions: Written versions of spoken dialogue and other sounds in a video, helping hard-of-hearing users understand the content.
- Closed captions: Captions that users can choose to display or hide.
- Audio Description: An audio track describing visual information not conveyed by sound, intended for visually impaired users.
- Caption Processing Technology
- Captioning Playback: When ICT displays video with closed captions, users must be able to view and select available captions (e.g., different languages, timing, color, positioning).
- Captioning Synchronization: Captions must be synchronized with the audio, generally within 100 ms of the corresponding time stamp for recorded material or availability for live captions.
- Preservation of Captioning: Caption data must be preserved when video is transmitted, converted, or recorded so that accessibility features remain intact.
- Captions Characteristics: Users should be able to adapt the displayed characteristics of captions (e.g., font, color), unless they are unmodifiable characters.
- Spoken Subtitles: A mode of operation should be provided to allow spoken output of available captions if their content is programmatically determinable.
- Audio Description Technology
- Audio Description Playback: The ICT must provide a mechanism to select and play available audio descriptions, either through a dedicated feature or by allowing selection of different audio tracks.
- Audio Description Synchronization: Synchronization between the video content and the audio description must be maintained.
- Preservation of Audio Description: Audio description data must be preserved during transmission, conversion, or recording of video to ensure it can be played back consistently.
- User Controls for Captions and Audio Description Controls to activate captions and audio descriptions must be at the same level of interaction as other primary media controls, where software controls exist. It is considered best practice to include controls for users to set these features on or off by default.
Clause 7 User Group
- Captioning directly supports users without hearing (WH) and limited hearing (LH)
- Audio descrption is essential for users without vision (WV) and with limited vision (LV)
- Secondary impact for users with limited coginition
- Captions can help reinforce the understanding of spoken dialog especially if the dialog is complex or fast
- Audio descriptions can help clarify complex visual scenes or actions that can be confusing
Clause 8: Hardware
This clause addresses accessibility requirements for ICT hardware, including its physical components and how users physically interact with it. It is a detailed chapter with many specific measurements.
- General Requirements
- The generic requirements outlined in Clause 5 also apply to hardware.
- Standard Connections: ICT must provide at least one input and/or output connection that conforms to an industry-standard, non-proprietary format (e.g., USB, Bluetooth), directly or via commercially available adapters, to ensure compatibility with assistive technologies.
- Colour: Color cannot be the sole visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. Alternative methods like text, shapes, or different sizes should be used.
You need to meet the general requirement of Clause 5 as well as clause 8 when you procure or develop hardware.
- Hardware Products with Speech Output
- Speech Volume Gain: Hardware with speech output must allow users to adjust the volume over a range of at least 18 dB. If incremental volume control is provided, there must be at least one step that is 12 dB above the lowest setting.
- Magnetic Coupling (aka Inductive Coupling) Communication devices normally held to the ear (fixed-line or wireless) with speech output must provide magnetic coupling compatible with hearing aids. This makes hearing aid better for users by: bypassing background noise, resulting in clearer audio (Hearing loop), preventing feedback or whistling when talking on the phone (Telecoil).
- Stationary ICT (Physical Access) This section ensures that stationary ICT (like ATMs, ticket
machines, or information kiosks) is physically accessible to as many users as possible, including wheelchair users
and those with limited reach.
- Clear Floor or Ground Space: Requirements specify minimum clear floor areas around stationary ICT to allow physical access for users with assistive technology. Changes in floor level within or entering stationary ICT must be ramped with a slope no steeper than 1:48, with exceptions for smaller changes.
- Approach: At least one full side of an access space inside stationary ICT must be unobstructed. Minimum dimensions for forward and parallel approaches are specified for ICT in closed environments or alcoves.
- Knee and Toe Clearance: Specific minimum dimensions are provided for knee and toe clearance under obstacles that are integral parts of the ICT, allowing wheelchair users to approach operable parts without hindrance.
- Reach Range: Requirements for both forward and side reach (unobstructed and obstructed) define the maximum and minimum heights for operable parts.
- Visibility: Display screens must be legible from a point 1015 mm (40 inches) above the center of the operating area to accommodate users in wheelchairs.
- Installation Instructions: Stationary ICT must come with installation instructions that guide how to install it in an accessible manner, adhering to relevant built environment accessibility requirements or, if none, to the standard's dimensions.
- Mechanically Operable Parts
- Numeric Keys: Physical numeric keypads arranged in a rectangular layout must have the number five key tactilely distinct from others for users who cannot see.
- Operation of Mechanical Parts: If operating a control requires grasping, pinching, or twisting, an accessible alternative that does not require these actions must be provided. Similarly, if a control requires a force greater than 22.2 N, an alternative requiring less force must be available.
- Keys, Tickets, and Fare Cards: If the orientation of these items is important for use, they must have a tactilely discernible orientation.
- Tactile Indication of Speech Mode: For shared ICT with speech output, a tactile indication must be provided to show how to initiate or if the speech mode is on or off
Clause 8 User Group
- Hearing aid compartibility requirement are primiarly for users with Limited hearing (LH)
- Physical access requirement supports users with limited reach (LR) and users with limited manipulation or strength (LMS)
- Non visual status indicator are key for users without vision (WV) and users with limited vision (LV)