These files contain the single-vowel waveforms used to make the double-vowel
stimuli. To make a double vowel, two single vowel waveforms were selected,
one was scaled by the appropriate scale factor, both vowels were added,
and the sum was scaled to a standard RMS value (60 dB re: 1). You need to
do the same to obtain the stimuli that were actually used in the experiment.
Files are in AIFF format, at 20 kHz sampling rate. They should be 270 ms
in duration, with 20 ms raised-cosine onset and offset ramps. Vowels were
paired with F0s arithmetically centred on 132 Hz.