The study involved about 50 children aged between two and four who attended the institute's day-care centre at Mahidol University's Salaya campus.

In the study, researchers looked into the difference between the effects of the Thai classical music and Mozart on the sleep of the children.

Researchers played "Khmer Sai Yok" and Mozart pieces to children in two separate groups as background music during the afternoon nap session that usually lasted from an hour to 90 minutes. The music volume was set to the same level in both groups

The darkness, temperature and other factors of the sleeping environment were kept the same in both groups as well as in a control group that slept without any music.

The average time taken to fall asleep by children in the control group was 24 minutes, whereas the group that was played Mozart took 15 minutes and the "Khmer Sai Yok" group just 10 minutes, said lead researcher Dr Nittaya J Kotchabhakdi.

Looking at the average duration of sleep in both study groups, researchers found the children listening to the Thai song slept about 10 minutes longer than the Mozart group, said Nittaya, who is a paediatrician and sleep-medicine expert.

The findings are to be presented at the World Association of Sleep Medicine Second World Congress to be held in Bangkok in February.

"Maybe it ["Khmer Sai Yok"] just fits in Thai children's minds - it cannot be guaranteed that Thai classical music would also work better with Chinese or other nationalities," said Nittaya.

"Since this type of music apparently promotes better sleep hygiene and poses no harm, parents should consider playing background music to promote better sleep in their children," she said.

The rule of thumb is to play soothing music and keep the volume rather low, she said.

She added that although music was good to encourage sleep, parents or care-givers are not recommended to always play music while children sleep.

"Real silence is still important to sleep well, too," said Nittaya.

Arthit Khwankhom

The Nation