The present paper is an addendum to a laboratory study published in 1959 on the normal thresholds of hearing for pure tones for an age-stratified sample of subjects drawn from a population exposed to minimal levels of industrial noise. It provides audiometric data (250–8000 cps) for 205 subjects in a 51- to 57-year-old group to supplement the earlier data for 500 subjects in four age groups between 18 to 49 years. The results of this study confirm the previously reported findings that (1) there is less than 5 db difference in the average sensitivity between right and left ears, (2) there is a decrease in hearing sensitivity with advancing age for both men and women, and (3) hearing loss with advancing age spreads progressively from higher to lower frequencies. Although women in general have better hearing and less intersubject variability than men, this trend is reversed for the lower frequencies in the 51- to 57-year-old age group. It is concluded that while the onset of presbycusis is later for women than for men, auditory deterioration proceeds at a faster rate in women than in men after about 50 years of age.