According to More Brain Power Needed for Mandarin Than English, Mandarin speakers use the left lobe, like English speakers, but they also use the right lobe, which is normally used to process melody, presumably because Mandarin is a tonal language:
Unlike English speakers, who use one side of their brain to understand the language, scientists at the Wellcome Trust research charity in Britain discovered that both sides of the brain are used to interpret variations in sounds in Mandarin. “We were very surprised to discover that people who speak different sorts of languages use their brains to decode speech in different ways; it overturned some long-held theories,” said Dr. Sophie Scott, a psychologist at the charity.Using brain scans on volunteers, Scott discovered that different areas of the brain are used to interpret words and intonation.
The left temporal lobe of the brain is active when English speakers hear the language but Mandarin speakers use the left and right lobe, which is normally used to process melody in music and speech.
Intonation is important in Mandarin because it gives different meanings to the same word. The word “ma” for example can mean mother, scold, horse or hemp, depending on the tone.
“We think Mandarin speakers interpret intonation and melody in the right temporal lobe to give the correct meaning to the spoken word,” Scott said in a statement.