Researchers in Jerusalem recently found out that the soothing sounds of Mozart's music may help preemies gain weight faster. According to their study, premature babies used up lesser energy when they were listening to the music by the famous 18th century composer than when they weren't.
The research they conducted was based on a study made in the early 90's where some experts claimed that college-level students who listened to Mozart's music for ten minutes showed an improvement in their IQ. It is because of this claim that these doctors from the Tel Aviv Sourasky Medical Centre decided to do a research on Mozart's effect on preemies.
When listening to Mozart's music, the babies had lower heart and respiratory rates which doctors see as the reason why their energy expenditures are lower. They aren't particularly clear as to why this happens but they speculate that this could be due to the calming effect of the music.