A comparison of procedures in "otometry": absolute versus equal-loudness judgments.

Normal-hearing men and women (N: 20) judged damped wave signal trains (3/sec; fc = .35, .5, .7, 1, 1.4, 2, 2.8, or 4 kc/s) to be on the verge from "normal" to "loud," and from "normal" to "soft." Judgments were binaural about 1 m from a loudspeaker. "Normal" (most comfortable ?) loudness was calculated at halfway in db between the two transition zones. A replication showed that 70% of Ss yielded the same "Normal" within 9 db for all fc, while only 35% could yield the same "Normal" within 6 db for all fc. Mean "Normal" for 1 kc/s was 72.8 db SPL re 20 mu Pa. Ss made equal-loudness judgments by adjusting other fc to this standard. Variances of equal-loudness judgments were 2--3 times better (smaller) than of "Normal" estimates. It was suggested that "Otometry" utilize the equal-loudness measurement procedure recommended originally by Victoreen (J. Acoust. Soc. Am., 1974, 55, 309-312).