Pitch-verticality and pitch-size cross-modal interactions

Two studies were conducted on cross-modal matching between pitch and sound source localization on the vertical axis, and pitch and size. In the first study 100 Hz, 200 Hz, 600 Hz, and 800 Hz tones were emitted by a loudspeaker positioned 60 cm above or below to the participant’s ear level. Using a speeded classification task, 30 participants had to indicate the sound source in 160 trials. Both reaction times and errors were analyzed. The results showed that in the congruent condition of high-pitched tones emitted from the upper loudspeaker, reaction times were significantly faster and the number of errors was significantly lower. Pitch was mapped on the vertical axis for sound localization. A main effect for sound source direction was also found. Tones coming from the upper loudspeaker were recognized faster and more accurately. Males were faster than females in identifying sound source direction. In the second experiment, 20 participants had to match 21 tones varying in pitch with 9 circles differing in visual angle on 42 trials. The results showed a clear inverse linear association between log-spaced tone pitch and circle diameter.