The present invention relates to a miniature electro-acoustic transducer including a magnetic circuit, a diaphragm and a voice coil operatively connected to the diaphragm. A top high-k dielectric is formed overlying the dielectric stack and the dielectric stack and the top dielectric are annealed. The pre-sintered PCD table may be substantially free of leaching by-products in a region at least proximate to the interfacial surface.