PROPERTIES OF DEAL FEATURES ideally a feature parameter should Nolan, 1983 show high between-speaker variability and low within-speaker variabili be resistant to attempted disguise or mimicry have a high frequency of occurrence in relevant materials be robust in transmission be relatively easy to extract and measurePROPERTIES OF IDEAL FEATURES ideally a feature parameter should（F.Nolan，1983）： • show high between-speaker variability and low within-speaker variability • be resistant to attempted disguise or mimicry • have a high frequency of occurrence in relevant materials • be robust in transmission • be relatively easy to extract and measure