Electromagneto-mechanical converter

An electromagneto-mechanical converter comprising a yoke and a plurality of winding teeth attached to said yoke, each said tooth being composed of a material which can carry the magnetic flux of a magnetic circuit, said material having a grain structure, each said tooth comprising

• a winding support element for holding a winding;
• an attachment region which attaches the tooth to the yoke;
• and
• a transition element which tapers from the winding support element to the attachment region, said transition element being immediately adjacent to the yoke
• wherein the grain structure of the material in the attachment region is disturbed so that the attachment region has a magnetic reluctance which is greater than the magnetic reluctance of the winding support element and the transition element,
• whereby magnetic flux which enters the transition element from the winding support element passes substantially from the transition element directly into the yoke, and the attachment region is substantially free of magnetic flux.