Facebook recently announced that ads on the social network will auto play with sound on. However, new research shows that many people watch ads with the sound off, and that subtitles could be the way to increase engagement when consumers hit the mute button.

Videos that include subtitles were found to perform better in brand awareness than those without. Such are the findings of new research conducted by AdColony in association with Millward Brown. Video ads by big brands such as Volvo, Sony and Disney were shown to consumers both with and without subtitles.

Creative for movie entertainment campaigns that was subtitled showed a 9.9% increase in brand awareness. With regards to purchase intent, some technology products as much as a 26% increase in purchase intent, and a specific technology product saw a 23% increase in communicating key product features through the use of subtitles.

"The research finds that subtitling does work for entertainment and FMCG brands to hit their targets and engage their audience," says Rob Cootes, director of video and programmatic at AdColony. "Imagery is not always enough to help resonate with an advert's message, so being able to communicate in another way can help to get this message across."

Facebook recently announced that videos will now be set to auto-play with sound as default. However, with research showing that 85% prefer to listen to online video without sound, probably more so when out and about using mobile, there's little doubt many will disable the auto-play sound option. Therefore, it makes sense for brands to provide subtitles, more so when there are details that, without audio, are hard to communicate.