The effect takes just a fraction of a second and can happen without us even being aware of it, the study reveals.

The finding was made by psychologists at Goldsmiths, University of London, after a series of experiments on students.

In the tests, the volunteers listened to 15 second clips of music and their reactions to photographs of a variety of faces were recorded.

The researchers used 120 different excerpts of instrumental pop, classical and jazz. After each piece was played, the students were asked to rate the mood of the faces in the pictures.

Results showed that happy music "significantly enhanced the perceived happiness of a face." Further studies of the volunteers' brain waves revealed that the effect of the music was almost instantaneous. It took just 50 milliseconds for changes to take place – too fast to be under our conscious control.

Similarly, listening to depressing music made sad faces appear more miserable.

The findings were published in the journal Neuroscience Letters.

One of the report's authors, Dr Joydeep Bhattacharya, described the results as "striking", especially in the way an emotionless face was rated happier after a burst of uplifting music.

He called for more research to discover how environmental sounds, such as background music in supermarkets, affected our emotions.

"What surprises us is that even as short as fifteen seconds of music can cause this effect. However more research is needed to find how long the effect lasts or if, and how, other factors such as musical preference and personality control this," he said.