A system, apparatus, and method for notifying output information to a remote terminal in response to an input signal of a sound includes first and second memory blocks to store, respectively, characteristic data representing characteristics of various sounds, and various items of output information corresponding thereto such that each item of the output information is associated with each sound. An input device collects a sound to provide an input signal, an analyzer device extracts characteristic data therefrom, and a controller device operates according to the extracted characteristic data to identify the item of the output information corresponding to the collected sound, which is then transmitted to the remote terminal. A new sound and a corresponding item of output information can be registered for updating the first/second memory blocks. A plurality of input devices and a source detection device may also be employed in accordance with the invention.