Speech therapists' patients range from the obvious - those who talk for a living such as teachers and salespeople - to the unexpected: mothers who scold their children too much. Raymond Fong, a speech therapist at Queen Mary Hospital, has seen a widening range of patients recently as people become aware that treatments exist for common problems like a hoarse voice. "When you're emotional, the muscles in your head get tight; it is not a good time to use your voice," Fong said, referring to cases like angry mothers who yell at their children. Like many people, they were not aware how easy it was to overuse their voice or use it in the wrong way, damaging their vocal chords, he said. "In the cases of some housewives, sometimes they just don't know how to stop. They may have just been shouting at their son, then go out, see a neighbour and start chatting. At the market, they run into friends and chat some more," he said. With such patients Fong tries to correct their habits of speech and breathing, and gives tips on protecting their voices. For example, clearing your throat is not good for the vocal chords, since it makes them hit against each other. Stimulating food like chilli is also not good for your voice, he said. And people should drink more water and give their vocal chords a chance to rest, when possible. Speech therapists' work extends to helping people with swallowing problems and hearing impairments. Fong particularly remembers a hearingimpaired two-year-old girl whom he taught to talk. Fong taught her vocabulary through games and other activities, and instructed her in distinguishing between different sounds. Now around nine years old, she attends a normal school. There's a special job satisfaction in such cases, Fong said.