Speaker normalization has previously been found to improve phonetic categorization (Cole et al., 2010;Nearey, 1978), increase a phonetic categorization model's match with human behavior (Apfelbaum and McMurray, 2015;McMurray and Jongman, 2011), and improve the performance of speech recognizers (Povey and Saon, 2006;Wegmann et al., 1996).
the following section describes the method we use for evaluating these features against human discrimination data.