The feature, which is likely to creep out some people, allows Happn users to send their connections a one-minute long personal audio clip in the app.
Happn cofounder and CEO Didier Rappaport said in a statement: "This new voice feature provides our members with another opportunity to connect on a more personal level and create meaningful relationships."
Happn also announced that is now has 10 million users worldwide.
The app, which launched in Paris in early 2014, connects people who have crossed paths in real life. By harnessing real-time geolocation technology, Happn shows users a timeline of the people they have crossed paths with throughout the day - those who were at the same place (within 800 feet) at the same time. They can then express their interest in another person by tapping a heart or dismiss them by tapping a cross. When two users like each other they can start talking to one another.
Rappaport told Business Insider last November that he hopes to catch up with rival Tinder in terms of user numbers by the end of next year. Tinder is thought to have over 25 million users but Happn is gaining 1.3 million more a month.
"We are not afraid to compete with Tinder," said Rappaport. "Tinder is well known because it was one of the first apps in this new way. I think by 2017 we should be equal."
In order to do this, he said he planned to launch a number of new features to further improve the overall experience users get, including the ability to send voice messages to crushes.
"For us, the evolution of our product is really important. We want to make a service that is more and more rich for our users and one that allows them to express themselves much more."
Happn
"The voice is something that is very emotional," the French entrepreneur continued. "Just listening to the voice of someone else can give you a lot of impression."
When Rappaport was asked whether he was worried about people misusing the voice messaging feature, he said: "You cannot talk with someone who hasn't agreed first to talk with you. Second, if you abuse the feature in a discussion with someone then it's very easy to someone to block you."
The dark side of dating apps
The number of mobile dating apps has surged in the last two years with apps like Bumble, Once, Hinge, and The Inner Circle all competing with each other and offering slightly different features.
They've been embraced by millions of young single people worldwide but health experts have claimed that they facilitate sexual encounters and are to blame for a rise in the number of sexually transmitted infections (STIs), notably HIV.
Rappaport said it's impossible to link dating apps with a rise in STI numbers.