YouTube seems to do a good job remembering which audio volume you’ve chosen. In other words, if you turn the volume way down for one video, the volume slider will start in that same position when you watch other videos. This is helpful for users and probably encourages them to spend more time on the site, since you feel like YouTube is adapting to your preferences.

However, I’ve noticed one problem with remembering the last volume someone used. If they turn the sound all the way down, other videos will start off muted too. Some users might forget they ever made this choice, and just assume the video they’re watching lacks sound entirely. This scenario is bad for users, video creators, and YouTube itself.

To remedy this, I propose a simple rule: if the user loads a new video but the audio is muted from their last session, show a gentle reminder near the volume slider, e.g. “Click here to turn the sound on”. This should be subtle, but more noticeable than the usual speaker icon with no bars next to it. The same approach can probably be applied to any website that remembers user preferences from one session to the next. Specifically, if a customer has chosen settings that might confuse them later, be sure to give them a friendly reminder about that at the start of future sessions.