A voice resolver unit processes audio data. The unit includes a noise detection and cancellation module operative on the audio data, a voice recognition engine to recognize voice in the output of the noise detection and cancellation module, a noise model scorer to match received audio data against at least two noise models to determine the type or types of noise in the audio data and a recognition analyzer to analyze the quality of the output of the recognition engine as a function of the operation of the noise detection and cancellation module according to the type or types of noise detected. The voice resolver may be used in an automation unit for a premises and an alarm system.