The invention relates to novel neurogenin proteins, nucleic acids and antibodies. The frame and hub are arranged to allow the hub to be moved forwards from the first position to the second position so as to insert the cannula into a patient and to be drawn backwards to a withdrawn position. , across the direction of loading, which is indicated by the arrows F. The present improvement is the provision of at least one loudspeaker, a plurality of analog drivers and the audio input supplied to a control processor which in turn drives one or more of the plurality of independent analog drivers. The first rigid link has a front end and a rear end.