The first at-rest position may be generally identical to the second at-rest position or may be different.

The locking lever (1) is movable between a rest position and an unlocking position and biased towards the rest position by means of a spring element (3).

The resilient bladder is deformable between an at-rest position and an in-ear position.

The elongate plunger actuates between an at-rest position and an insertion position to cause the resilient bladder to be deformed from the at-rest position to the insertion position before the device is located in the ear canal.

These gripping members move from their idle position to an extreme position and back.

The first portion of the second electrode layer is configured to move between a relaxed position spaced away from the first electrode layer and an actuated position spaced closer to the first electrode layer than is the relaxed position.

The support arms are biased towards each other in a resting position.

The self-calibration involves measuring home position and full travel position values for the motor.

In a rest position of the protective cover (28, 32), a tool (22) is completely covered.

The elongate plunger actuates between the at-rest position and an insertion position to assist the resilient bladder to be deformed into the in-ear position.

According to the invention, the fastener (1), in the resting position thereof, is totally flat along a general plane (P).

Most babies hold their hands in this position at rest.

The plunger actuates in the insertion position without extending a front end portion of the bladder forward of a position of the front end portion when the bladder is in the at-rest position.

The pedal (16), in an inactive position holds the drive wheel (14) in a position where it does not contact the rear wheel (24).

The creep control arm interacts with the protective cover to provide a first at-rest position for the cartridge.