Patent ID: 7558727

Claim:
A method of synthesizing a first sound signal based on a second sound signal, the first sound signal having a required first fundamental frequency and the second sound signal having a second fundamental frequency, the method comprising the steps of: determining required pitch bell locations in the time domain of the first sound signal, the pitch bell locations being distanced by one period of the first fundamental frequency, providing a plurality of pitch bells by windowing the second sound signal based on pitch bell locations in the time domain of the second sound signal, the pitch bell locations of the second sound signal being distanced by one period of the second fundamental frequency, said windowing being determined based on a type of said second sound signal; randomly selecting one of said pitch bells from the provided pitch bells for each of the required pitch bell locations, said selection being uniformly distributed among said number of provided pitch bells; and performing an overlap and add operation on the selected pitch bells for synthesizing the first signal.