Synthetic speech could make public announcements easier to understand

Public announcements in noisy places like railway stations, airports or sports venues could become quieter and clearer in the future, Scottish researchers say. Scientists at the University of Edinburgh say they've developed software that can alter speech before it is broadcast over speakers, making it more audible amid background noise. They began their research by conducting tests to pinpoint the components of speech that are most easily heard by people in a noisy place. They found that listeners in loud situations pay most attention to the parts of speech that are easiest to hear, and then use those to decipher what is being said. "Noisy environments make it difficult to understand what is being said and simply making speech louder isn't the smartest solution," study author Cassia Valentini Botinhao said. Researchers said they developed a mathematical computer program to analyze spoken words and enhance the sounds that best help listeners hear what is being said, to make speech better understood overall. In tests, the manipulated speech was found to be much easier to understand than natural speech, they said. "Our findings could offer an alternative, by making speech more intelligible without turning up the volume," Botinhao said. The manipulation techniques could also be used to improve smartphone voices or satellite navigation system audio, the researchers said.