Abstract: A method and apparatus for detecting sleep state from both physiological and environmental sensors. The analysis is performed on segmented signals and sleep state is detected if sleep probability is above a predefined threshold. The method may be applied to any noisy signal or set of signals acquired from a user and environment in which there is uncertainty about the presence of sleep state and in real-time analysis of signals, preceding further analysis of the sleep signal.

Abstract: A method and apparatus for detecting voice activity in an audio signal by taking the ratio of the entropy and the energy band ratio of the power spectrum of the audio signal. The signal is classified as containing voice episodes if the voice activity ratio is above a predefined threshold. The method may be applied to any noisy signal in which there is uncertainty about the presence of voice activity and in real-time analysis of sound, preceding further analysis of the sound signal.