Hearing disabilities range from mild hearing loss to profound deafness. They also include auditory processing disorders — where the ear can detect sound normally but the brain has difficulty interpreting it — and conditions like tinnitus that create persistent noise interference.
Approximately 3 million Canadians identify as having some degree of hearing loss, and hearing disability is the most prevalent sensory disability for adults over 65. The Deaf community in Canada also has a distinct cultural identity, with many Deaf Canadians considering American Sign Language (ASL) or Langue des signes québécoise (LSQ) their first language, and English or French their second.
Types of hearing disability
Type
Description
Mild hearing loss
Difficulty with soft sounds or speech in noisy environments
Moderate hearing loss
Difficulty following conversation without hearing aids
Severe hearing loss
Only loud sounds are audible; relies heavily on lip-reading and visual cues
Profound deafness
Little to no functional hearing
Unilateral hearing loss
Significant loss in one ear — difficulty locating sounds, speech in noise
Auditory processing disorder
Normal hearing but difficulty interpreting speech, especially with background noise
Tinnitus
Persistent ringing or noise that interferes with listening
Deafblindness
Combined vision and hearing loss — uses braille, tactile signing, or DeafBlind relay services
Assistive technologies
Developer Author
Captions and subtitles
Captions are the primary accessibility tool for audio content on the web. There are two types:
Closed captions (CC) — can be toggled on/off by the user; most video players support them
Open captions (OC) — burned into the video; always visible
Subtitles — translate spoken content into another language; do not include non-speech audio descriptions
High-quality captions include:
All spoken dialogue
Speaker identification when multiple speakers are present
Relevant non-speech sounds: [door slams], [upbeat music plays], [audience laughter]
On-screen text and titles that are part of the content
Transcripts
Full-text transcripts of audio and video content allow users to read the content entirely — useful for users who cannot play media, prefer reading, or need to search content. Transcripts should be structured (with headings for sections) and describe visual content that is not conveyed by the audio alone.
Hearing aids and cochlear implants
Many hard-of-hearing users listen through hearing aids or cochlear implants. These devices:
Amplify sounds but may also amplify background noise
May use Bluetooth to connect directly to computer/phone audio
Are not effective for extremely poor-quality audio (low bitrate video, background music over speech)
Real-time captioning services
For live events and meetings, professional human captioners (CART — Communication Access Realtime Translation) or automatic speech recognition (ASR) provide real-time text. Platform quality varies significantly.
Video relay services
Deaf users who use ASL or LSQ can communicate via phone through video relay services, where a sign language interpreter relays the conversation. Customer service phone numbers should have relay service alternatives.
Barriers on the web
Video without captions
Barrier
Videos, webinars, tutorials, and promotional content play audio that cannot be heard — users who are Deaf or hard of hearing miss the content entirely.
Assistive Technology
None — captions are the access method
Design Consideration
All pre-recorded video with audio must have synchronized captions (WCAG 1.2.2, Level AA). Live video should have captions (WCAG 1.2.4, Level AA). Auto-generated captions are a starting point but require human review for accuracy.
Audio-only content without transcripts
Barrier
Podcasts, audio announcements, and voice messages have no text equivalent — Deaf and hard-of-hearing users, and anyone in a sound-restricted environment, cannot access the content.
Assistive Technology
None — transcripts are the access method
Design Consideration
All pre-recorded audio-only content must have a text transcript (WCAG 1.2.1, Level A). Transcripts should be in accessible HTML, not a PDF, and be easily findable near the player.
Video without audio description
Barrier
Educational or instructional video contains important visual information that is not described in the audio track — users who are both deaf and blind, or who listen while not watching, miss the visual content.
Assistive Technology
Screen readers with video description track
Design Consideration
Audio description adds a narration track describing important visual information. Required at WCAG Level AA (1.2.5) for pre-recorded video. Where the main audio already fully describes the visual, it may not be needed — but document the decision.
Auto-playing audio
Barrier
A page starts playing audio or video automatically — users who are hard of hearing and using hearing aids may experience feedback or distortion; users using screen readers have the audio interfere with their screen reader's speech output.
Assistive Technology
Screen readers, hearing aids
Design Consideration
Never autoplay audio for more than 3 seconds without providing a mechanism to pause or stop it (WCAG 1.4.2, Level A). Better practice: never autoplay audio at all.
No visual alerts for audio notifications
Barrier
System or in-app notifications are delivered only as sounds (beeps, chimes) — Deaf users and users who have their device muted miss time-sensitive information.
Assistive Technology
None — visual indicators are the access method
Design Consideration
All audio alerts must have a visual equivalent: a banner, badge, flashing indicator, or on-screen message. This applies to chat systems, booking confirmations, error sounds, and session timeout warnings.
Poor quality or missing captions
Barrier
Auto-generated captions are inaccurate (wrong words, missing speaker identification, no punctuation) — while technically present, they create a frustrating, error-prone experience that misrepresents the content.
Assistive Technology
Captions
Design Consideration
Caption accuracy is a legal requirement, not just a best practice. The CRTC requires 95% accuracy for broadcast captions. For web content, inaccurate captions may constitute providing an inaccessible format under the AODA. Review and correct all auto-generated captions before publishing.
Design and content considerations
Author Designer
Caption styling
When you have control over caption appearance (branded video players, native apps):
Minimum 18pt equivalent font size
High-contrast text against background (white text on semi-transparent black is standard)
Maximum 2 lines of text visible at once
Captions should not obscure lower-third graphics or speaker faces when possible
Allow users to customize caption size, font, and contrast if possible
Plain language matters more
Many Deaf Canadians who use ASL or LSQ as their first language read English or French as a second language. Written content at a lower reading level benefits them significantly. See Plain Language Writing for guidance.
Don’t rely on audio for alerts
Every notification that could be delivered as a sound must also have a visual equivalent:
✓ A toast notification that slides in when a file upload completes
✓ A badge count that updates when a new message arrives
✗ A “ding” sound when a form submits successfully, with no other feedback
Sign language versions
For high-priority or high-traffic content (emergency information, government services, health guidance), consider providing ASL or LSQ video versions. This goes beyond WCAG requirements but significantly improves access for the Deaf community.
Development considerations
Developer
Caption file formats
Common caption file formats for the web:
WebVTT (.vtt) — the standard for the HTML5 <video> element
SRT (.srt) — widely supported, plain text format
TTML (.ttml) — used by some broadcast and streaming platforms
Place transcripts directly below or near the media player. Do not link to a separate page unless the transcript is very long — even then, provide a brief summary inline.
<figure> <video controls> <source src="podcast-ep42.mp4" type="video/mp4" /> <track kind="captions" src="podcast-ep42.vtt" srclang="en" default /> </video> <figcaption> Episode 42: AODA Compliance in 2024 (23 minutes) </figcaption></figure><details> <summary>Read the full transcript</summary> <div class="transcript"> <p><strong>[Host]:</strong> Welcome back to Accessible Canada...</p> <!-- full transcript --> </div></details>
Avoid audio-only CAPTCHA
Audio CAPTCHA is often inaccessible to users with both hearing and cognitive disabilities. If you must use CAPTCHA, provide multiple modalities. Better: use non-CAPTCHA alternatives (honeypot fields, rate limiting, email verification).
Testing
Caption quality check
Watch the video without audio — can you follow the complete content from captions alone?
Are all speakers identified when there are multiple voices?
Are relevant sound effects and music noted?
Is punctuation present and correct?
Do captions sync with speech? (No more than 2 seconds behind)