How to Produce Audio Descriptions for Visual Course Content

Over 1 billion people live with disabilities worldwide. For those with visual impairments, inaccessible course content creates major barriers to learning. Audio descriptions turn visual elements into spoken words, making education accessible to everyone. Without them, courses fail basic accessibility standards and exclude learners who need them most.

audio descriptions are narrated explanations of visual content that help blind or low-vision learners understand videos, images, and diagrams. Unlike captions which transcribe speech, audio descriptions fill in gaps for visual information not covered by the audio track. For example, in a science video showing a chemical reaction, audio descriptions explain color changes, bubbles, and equipment setup that the narrator doesn't mention.

Why Audio Descriptions Matter for Course Content

WCAG 2.1 Level AA requires audio descriptions for pre-recorded video content. This standard exists because visual information is often critical to learning. A math tutorial showing a graph's trend without describing the axes or data points leaves blind students unable to follow along. Similarly, a history lecture displaying a historical photo without describing the people, setting, or context makes the content useless for visually impaired learners. Audio descriptions bridge this gap by translating visual details into accessible language.

Real-world impact is clear. After adding audio descriptions to a biology course video, enrollment from visually impaired students increased by 35%. This isn't just about compliance-it's about creating inclusive classrooms where every learner can succeed.

Step-by-Step Guide to Producing Audio Descriptions

1. Identify key visual elements-Watch your video and note every visual element not explained by the audio. For example, in a math video showing a graph, describe the axes labels, data points, and trends. In a history documentary, note clothing details, background scenery, and key objects.
2. Write concise descriptions-Aim for 2-3 sentences per visual element. Avoid repeating audio narration. If the video says "sales increased 20%," describe the graph's shape: "The line slopes upward from $300K to $500K over four quarters." Keep it focused on what's visually distinct.
3. Record the audio-Use a clear, neutral voice. Tools like Descript or Audacity help sync descriptions with video timestamps. Ensure descriptions don't overlap with dialogue. For instance, pause descriptions during spoken explanations to avoid confusion.
4. Test with screen readers-Play the video with JAWS or NVDA. Check if descriptions are clear, timely, and match the visual content. Adjust timing if descriptions start too late or run too long.
5. Implement in your LMS-Upload the described video to platforms like Canvas or Moodle. Ensure the system supports audio description tracks. Most modern LMS platforms automatically recognize and play descriptions when enabled.

Tools for Creating Audio Descriptions

Several tools simplify the process. Descript offers AI-powered transcription and audio editing. You can easily add descriptions to video tracks and export them as separate audio files. Adobe Premiere Pro allows precise syncing of audio descriptions with video frames. For free options, Amara provides a web-based platform for collaborative captioning and description work.

Best Practices and Common Mistakes

Follow these tips to avoid pitfalls:

• Keep descriptions brief-Aim for 2-3 seconds per description. Long descriptions disrupt the flow. For example, describe a chart as "Bar graph shows sales peaked in Q4 at $500K" instead of a detailed breakdown.
• Don't repeat audio-If the narrator says "the graph shows rising sales," your description should focus on visual details like "the line slopes upward from $300K to $500K over four quarters."
• Test with real users-Get feedback from blind learners. They'll know if descriptions are clear and timely.
• Avoid unnecessary details-Describe only what's relevant. In a history video, "a soldier in blue uniform" matters; "the soldier's shoes are brown" doesn't.

Real Examples for Different Content Types

Here's how to describe common visual elements:

• Science video-"A beaker with red liquid bubbles as heat is applied. The color changes from red to purple at 60°C." (If the audio already mentions the temperature, focus on the color change.)
• Math diagram-"Two intersecting lines form a right angle. The equation x² + y² = 25 is labeled on the graph." (Avoid repeating the equation's name if the audio says "the circle equation."
• Historical photo-"A black-and-white photo of a protest march. Signs read 'Equal Rights' and 'End Discrimination' held by diverse crowd." (If the audio describes the event, focus on the visual elements not covered.)