Twelve patients were submitted to ossicular dissections for between 2 1/2 and 35 minutes during ear surgery. A comparison between premanipulatory and portmanipulatory electrocochleographic threshold determinations did not disclose any thrshold shifts. The results lend support to the conclusion that manipulations on ;the ossicular chain, performed with customary care, are less harmful to the inner ear than other generally recognized threats to the cochlea during surgery, eg, perilymph fistulae and acoustic traumas from the drill.