Zwicker tone interval settings are slightly more variable than pure-tone matches.

Evidence

To compare the reliability of the musical interval adjustments in the ZT conditions with that in the matched PT conditions, we calculated the ratio of the respective SDs. This was done as follows: (1) Separately for each subject, each musical interval (minor third, perfect fifth), each reference condition (ZT, PT) and each LEF (or reference PT tone frequency) we determined the SD of the adjusted frequencies across the 12 interval adjustments expressed as a percentage of the geometric mean; (2) These were geometrically averaged across the eight LEFs (or PT frequencies) to obtain the representative SD; (3) The representative SD for the ZT was divided by the representative SD for the PT. This ratio is shown in the group of two bars on the left-hand side of each panel in Fig. 2 . Musical interval adjustments for the ZTs were somewhat more variable than for the matched PTs; the ratio of the SDs was between 1.1 and 2.2. Four univariate analyses of variance conducted separately on the data for each subject (using the SD of the logarithms of the individual adjusted frequencies within a given LEF or reference frequency as input data) showed that for three of the subjects the SDs were significantly larger for the ZT than for the PT conditions (with p < 0.01 for subjects 1 and 2, and p < 0.05 for subject 3). The number above each bar in Fig. 2 indicates the size of the representative SD for the PT condition in percent (ranging from 0.9‑1.5 %). The representative SD for the ZT condition ranged from 1.2‑2.5 %. By comparison, the SDs observed by Burns and Feth ( 1983 ) for the same musical interval adjustments were on average 1.2 % and 4.2 % for 1-kHz and 10-kHz 70-dB SPL reference tones, respectively. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5418