Furthermore, for example, there may be a configuration in which the fulcrum shaft 21 is at the middle portion of the relative surface 3a but is out of the middle portion of the facing surface 2a (see FIGS. 33 and 34). The base body 2 and the rotating body 3 may be in any shape. For example, the facing surface 2a may be formed in a circular shape and the relative surface 3a (bottom surface 3c) may be formed in a non-circular shape such as an oval shape, whereby the rotating body 3 protrudes from the base body 2 by a varying amount and at a varying position as the rotating body 3 is gradually rotated relative to the base body 2 so that the rotating body 3 can be brought into contact with part of the ear 100.

FIGS. 35 to 39 show the audio output apparatus 1 in different orientations.

<Present Technology>

The present technology can be configured as follows.

(1)

An audio output apparatus including:

a speaker that outputs a sound;

a base body that includes a facing surface and is at least partially inserted into an ear canal of an ear;

a rotating body that includes a relative surface at least partially facing the facing surface and is rotatable relative to the base body; and

a fulcrum shaft that is present at least at one of a position displaced from a middle portion of the facing surface or a position displaced from a middle portion of the relative surface, the fulcrum shaft serving as a fulcrum of rotation of the rotating body relative to the base body, in which