In accordance with the invention, a timing signal is recorded containing {HEAD ~ certain information} that is used, upon playback, to produce a reference marker which is compared with the detectable characteristics of recorded information signals to produce {TAIL ~ a measure} of skew distortion 
In accordance with the invention , a timing signal is recorded containing { HEAD ~ certain information } that is used , upon playback , to produce a reference marker which is compared with the detectable characteristics of recorded information signals to produce { TAIL ~ a measure } of skew distortion
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH