An ear piece is formed for insertion and placement in an external auditory canal. The ear piece has an inflatable which, when it is inflated, expands and braces against the walls of the auditory canal. When it is deflated, it may be withdrawn from the auditory canal. The ear piece may be used in connection with a hearing aid, an MP3 player, a cell phone, or the like. A pump is provided for inflating the balloon and a valve may be controlled for selectively deflating the balloon. The air intake to the pump is disposed so as to be protected against contamination from inside the auditory canal. For that purpose it is formed inside a housing the air inlet of which is as far outside the ear canal as possible. In the case of a behind-the-ear application, the intake opening is formed in the housing that is to be placed behind the user's ear.