In a preliminary experiment of between 5 and 8 2–h sessions per listener, the following stimulus parameters were tested and determined individually for each listener. Firstly, ΔF0 was chosen so as to give medium to high performance in context trials. Secondly, the percentage of mistuning of harmonics 3 and 4 was chosen independently so as to give low (but above chance) to medium performance in test trials that were interspersed within context blocks providing reliable frequency information for the given harmonic; above chance performance was required to allow measurement of a possible deterioration in the unreliable context condition, and small amounts of mistuning giving low to medium performance rather than large amounts of mistuning were desirable to prevent perceptual segregation of the mistuned harmonic. The final stimulus parameters that were used in the main experiment are shown in Table 1 for each listener. ΔF0 in the context trials was between 1 and 1.5 %, while the amount of mistuning in the test trials was between 0.3 and 2.5 %.TABLE 1Stimulus parameters used in the main experiment for individual listenersListenerContext trials: ΔF0 [%]Test trials: mistuning of 3rd harmonic [%]Test trials: mistuning of 4th harmonic [%]11.02.51.521.51.52.031.01.51.041.01.01.2551.00.750.7561.50.60.571.00.60.3