Show m In mo o O. O r r. e e t. t ta a e t t. ti i s a Pe 1 t P r f- f y The CPS disclosure of an minute 18 tone in one of the subpoenaed Watergate tapes has renewed speculation as to whether more subtle aber- aber rations perhaps even deliberate ate ones could be detected Audio experts at the Company a major manufacturer manufacturer manufacturer of tape agree that tapes can be doctored by editing voices in or out by rearranging rearranging ing words or by dubbing in an impersonators impersonator's voice After the tapes are the physical splices would be eliminated eliminated eliminated elim elim- and the ear couldn't detect them However by using certain sophisticated equipment skilled skilled skilled skill skill- ed specialists could uncover doctoring Splicing interrupts a tapes tape's magnetic field which will show up on an scope Background sounds like a aradio aradio radio playing or a clock ticking ticking ticking tick tick- ing might also give away attempted attempted attempted at at- tempted alterations An electronic electronic electronic elec elec- signal correIa tor can lock in on a background noise and register any frequency sh shifts ts that occur because of splicing Nevertheless the experts agree that it would be nearly impossible to detect the removal removal removal re re- re- re moval of entire conversations by cutting at spots where the recorder had stopped Also the possibility of detection detection detection de de- de- de depends on the type of equipment used for the bugg bugg- ing Whether the recorders used to monitor Presidential c conversations o n v e r were highly tic ted ted-as former P Presidential esi- esi 4 sop sophisticated as i aide Alexander Butterfield Butterfield Butter- Butter r f field eld once indicated to the Senate Committee Committee- Watergate or no Apollo system as President Nixon reaffirmed in last weeks week's press conference has yet to be resolved To garble the air even more tape specialists say only a small number of persons are t skilled enough to detect sophisticated tape doctoring and many of those work for forthe forthe forthe the government one expert reported |