As described above, in a state where the audio output apparatus 1 is fitted in the ear 100, music data (sound signals) transmitted from, for example, a communication device is received by the antenna, and the received music data is controlled by the control board 25, and a sound is output from the speaker 22. The sound output from the speaker 22 passes through the sound output holes 9a, 9a, the sound output holes 13a, 13a, and the ear canal 113 to reach the eardrum.

Note that, in a state where the audio output apparatuses 1, 1 are fitted in the left ear 100 and the right ear 100, respectively, a signal received by the antenna in one audio output apparatus 1 is transmitted to the antenna in the other audio output apparatus 1, thereby enabling the sound to be output in stereo mode. However, another configuration is also possible in which music data (a sound signal) transmitted from the communication device is received by each of the antennas in the two audio output apparatuses 1, 1.

Furthermore, when a sound is output from the speaker 22, an external sound is input to the microphone 23 through the sound input holes 10b, 10ba, . . . , and a noise canceling function of canceling an input sound constituting a noise is executed. The noise canceling function is fulfilled by, for example, detecting a noise in an external sound and generating, through the control board 25, a noise canceling signal so that the user perceives each detected noise to a minimum extent.