Here’s one trick to make yourself feel happier: Listen to your own voice—digitally manipulated to make it sound cheery. That’s one potential application of a new study, in which researchers modified the speech of volunteers as they read a short story by Japanese writer Haruki Murakami. The team then altered the voice’s pitch, among other features, to make it sound happy, sad, or fearful. Compare this normal voice:

with the same voice modified to sound afraid:

Listening to their own modified voices in real time through a headset, only 16 of 109 participants detected some kind of manipulation. The rest took the voice’s emotion as their own, feeling sad or happy themselves. (The result was less clear for fear.) The researchers suggest that emotions expressed through our voices are part of an ancient, unconscious primate communication system, whereas we have more conscious control over the words we utter. The voice manipulation software is available online, so anyone can experiment with it. The scientists speculate that emotion manipulation could help treat psychiatric disorders like depression. It could also change the mood of online meetings or gaming, they say, or even lend more emotional impact to singing performances.