00297nam a22000737a 4500245013800000260005800138300001000196650001700206  aIS 10776-4:1984-Methods of Measurement of Electro-acoustical Characteristics of Hearing Aids, Part 4: Hearing Aids with Bone Vibrator  aNew Delhi :bBureau of Indian Standards (BIS),c1984.  a14 p.  aHearing aids