This paper will compare various sound insulation measures as predictors of the grouped subjective ratings obtained from a field survey of 600 subjects and the airborne sound insulation of their 300 party walls. The subjects lived in both row housing and multi-floor apartment buildings in three different Canadian cities. The questionnaire first asked about general issues concerning the subjects building followed by more specific questions rating the sound insulation and the audibility of various noises. Sound transmission loss measurements were made in 1/3 octave bands from 100 to 4000 Hz. In addition to the standard ISO and ASTM single number ratings, 20 different single number sound isolation measures were calculated. Most were simple variations of the standard quantities. The standard STC rating (including the 8-dB rule) was one of the better predictors of most responses. Excluding the 8-dB rule decreased correlations with responses and especially those concerning hearing musical sounds. Several responses were best correlated with transmission loss values in the 160- and 200-Hz bands.