I add transcripts to recorded material.
Not only do transcripts ensure accessibility for students with a hearing impairment, but it can also serve as a visual and text-based scaffold for all students.
Stichting Accessibility (see link under Step by Step Sharing Videos) also suggests that audio files that describe images are also included.
Step by Step
Online videos in Brightspace
Checking audio descriptions
Close your eyes and listen to the video. Is the relevant information presented clearly? Also consider actions, body language, and text or images that appear in the video. Whatever is not clear can be supplemented with the addition of descriptive audio clips.
Checking subtitles and transcripts
Turn off the sound and watch the video. Is all the relevant information clear and meaningful? Take into consideration sound effects or individual affects. Anything that is missing or impeding comprehension can be added to the subtitles or transcripts.