A robot cleaner , comprising: a sound input unit having one or more microphones, and configured to receive an ambient sound; a sound recognition unit configured to recognize the received ambient sound, in a separation manner into an event sound and an environmental sound; and a message output unit configured to output a message corresponding to the event sound or the environmental sound, characterized by : a storage unit configured to store an event sound model with respect to the event sound, and an environmental sound model with respect to the environmental sound, and the sound recognition unit includes: a first recognition portion configured to recognize the event sound at first time intervals, based on the ambient sound and the event sound model; a second recognition portion configured to recognize the environmental sound at the first time intervals, based on the ambient sound and the environmental sound model; and a third recognition portion configured to recognize the environmental sound at second time intervals longer than the first time intervals, based on the ambient sound and the environmental sound model. a sound input unit having one or more microphones, and configured to receive an ambient sound; a sound recognition unit configured to recognize the received ambient sound, in a separation manner into an event sound and an environmental sound; and a message output unit configured to output a message corresponding to the event sound or the environmental sound, characterized by : a storage unit configured to store an event sound model with respect to the event sound, and an environmental sound model with respect to the environmental sound, and the sound recognition unit includes: a first recognition portion configured to recognize the event sound at first time intervals, based on the ambient sound and the event sound model; a second recognition portion configured to recognize the environmental sound at the first time intervals, based on the ambient sound and the environmental sound model; and a third recognition portion configured to recognize the environmental sound at second time intervals longer than the first time intervals, based on the ambient sound and the environmental sound model. a storage unit configured to store an event sound model with respect to the event sound, and an environmental sound model with respect to the environmental sound, and the sound recognition unit includes: a first recognition portion configured to recognize the event sound at first time intervals, based on the ambient sound and the event sound model; a second recognition portion configured to recognize the environmental sound at the first time intervals, based on the ambient sound and the environmental sound model; and a third recognition portion configured to recognize the environmental sound at second time intervals longer than the first time intervals, based on the ambient sound and the environmental sound model. a first recognition portion configured to recognize the event sound at first time intervals, based on the ambient sound and the event sound model; a second recognition portion configured to recognize the environmental sound at the first time intervals, based on the ambient sound and the environmental sound model; and a third recognition portion configured to recognize the environmental sound at second time intervals longer than the first time intervals, based on the ambient sound and the environmental sound model. <EOS>