Threshold determinations were made at 9 frequencies from 250 to 8,000 cps on a Beltone audiometer provided with PDR-8 earphones calibrated in a National Bureau of Standards Coupler 9-A. Measurements were made on both right and left ears, and all subjects were individually tested in an anechoic chamber. There are only minor differences (less than 5 db.) between the average sensitivity of right and left ears. In the 51-65 age groups, women have poorer hearing and greater variability at the lower frequencies, i.e., at least below 1,000 cps, while the men have significantly poorer hearing and greater variability at least from 3,000 cps and above. For both men and women, there is a decrease in hearing sensitivity with increasing age and a progressive spreading of the loss from the higher to the lower frequencies. Men are more affected than the women, with the hearing loss occurring at an earlier age by at least 5 years (32 years vs. 37 years) and producing a greater degree of auditory impairment at the higher frequencies.