performing {HEAD ~ a similarity measurement} between the speaker identity candidate match scores and {TAIL ~ probe match scores} to obtain similarity values; and 
between
performing { HEAD ~ a similarity measurement } between the speaker identity candidate match scores and { TAIL ~ probe match scores } to obtain similarity values ; and
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH