A sound output device comprising: a microphone part configured to generate a sound signal based on an ambient sound; a wireless communication part configured to receive data from another sound output device, wherein the data received from the other sound output device comprises a sound environment information and a microphone signal of the other sound output device; a digital signal processor (404L, 404R) configured to perform a reverb process on the sound signal based on a reverb type, wherein the sound output device is configured to select the reverb type from a reverb type database of the sound output device based on the sound environment information; an adder part (428R, 428L) configured to combine the microphone signal of the other sound output device with the sound signal subjected to the reverb process in order to generate a combined signal; a sound output part configured to output a sound generated from the combined signal; a sound guide part having a hollowed structure and configured to capture the sound generated by the sound output part at one end of the sound guide part, and to output the sound at another end of the sound guide part; and a supporting member configured to fit to a vicinity of an opening of an ear canal of a listener and to support the other end of the sound guide part near the opening of the ear canal, wherein the supporting member includes an opening part configured to allow the opening of the ear canal to open to the outside when the sound output device is worn such that the other end of the sound guide part and the supporting member do not completely cover the opening of the ear canal. a microphone part configured to generate a sound signal based on an ambient sound; a wireless communication part configured to receive data from another sound output device, wherein the data received from the other sound output device comprises a sound environment information and a microphone signal of the other sound output device; a digital signal processor (404L, 404R) configured to perform a reverb process on the sound signal based on a reverb type, wherein the sound output device is configured to select the reverb type from a reverb type database of the sound output device based on the sound environment information; an adder part (428R, 428L) configured to combine the microphone signal of the other sound output device with the sound signal subjected to the reverb process in order to generate a combined signal; a sound output part configured to output a sound generated from the combined signal; a sound guide part having a hollowed structure and configured to capture the sound generated by the sound output part at one end of the sound guide part, and to output the sound at another end of the sound guide part; and a supporting member configured to fit to a vicinity of an opening of an ear canal of a listener and to support the other end of the sound guide part near the opening of the ear canal, wherein the supporting member includes an opening part configured to allow the opening of the ear canal to open to the outside when the sound output device is worn such that the other end of the sound guide part and the supporting member do not completely cover the opening of the ear canal.