1. A computer-implemented method of speaker identification, comprising: determining a representation for each linear operator of a plurality of linear operators, each linear operator representing variability of statistical voice features with respect to a statistical model component among a plurality of statistical model components, in terms of (i) a first orthogonal operator specific to the respective linear operator of the plurality of linear operators, (ii) a weighting operator specific to the respective linear operator of the plurality of linear operators, and (iii) a second linear operator common to the plurality of linear operators and having a first dimension larger than a second dimension of the plurality of linear operators; computing statistical voice characteristics of a particular speaker using at least the representations corresponding to each of the plurality of linear operators determined; and employing the statistical voice characteristics of the particular speaker to determine whether an input speech signal corresponds to the particular speaker.