Sensitivity to Tonality across the Pitch Range

Octave Bias in Pitch Perception: The Influence of Pitch Height on Pitch Class Identification

Pitch height and pitch class are different, but strictly related, percepts of music tones. To investigate the influence of pitch height in a pitch class identification task, we systematically analyzed the errors-in terms of direction and amount-committed by a group of musicians. The aim of our study was to verify the existence of constant errors in the identification of pitch classes across consecutive octaves. Stimuli were single piano tones from the C major scale executed in two consecutive octaves. Participants showed different response patterns in the two octaves. The direction of errors revealed a constant tendency to underestimate pitch classes in the lowest octave and to overestimate pitch classes in the highest octave. Thus, pitch height showed to influence pitch class identification. We called this bias "pitch class polarization", since the same pitch class was judged to be respectively lower and higher, depending on relatively low or high pitch height.

Tonal priming is resistant to changes in pitch height

Research on tonal priming has consistently shown that tonally expected events are processed more efficiently and has confirmed that the locus of the effect is cognitive rather than sensory. However, it is also important to investigate the role of pitch height, because models of tonal priming collapse across octaves, yet it is possible that pitch height may modulate the effectiveness of tonal priming. We systematically tested this issue by varying the pitch heights of a related (tonic) or a less-related (subdominant) target chord following a tonal context. Musically untrained participants (N = 30) made speeded consonant/dissonant judgments of the final chord of an eight-chord sequence. The effects of tonal priming emerged in accuracy and reaction time measures for all octaves, except for a ceiling effect on accuracy in the matching (original pitch height) condition. In a second experiment, we increased the shift to two octaves and compressed the chords to eliminate overlap between the target and context chords; again, tonal priming emerged. These findings have implications for the behavioral study of tonal priming and support the assumption of octave equivalence in computational models.

Designing the Model Human Cochlea: An Ambient Crossmodal Audio-Tactile Display

We present a model human cochlea (MHC), a sensory substitution technique and system that translates auditory information into vibrotactile stimuli using an ambient, tactile display. The model is used in the current study to translate music into discrete vibration signals displayed along the back of the body using a chair form factor. Voice coils facilitate the direct translation of auditory information onto the multiple discrete vibrotactile channels, which increases the potential to identify sections of the music that would otherwise be masked by the combined signal. One of the central goals of this work has been to improve accessibility to the emotional information expressed in music for users who are deaf or hard of hearing. To this end, we present our prototype of the MHC, two models of sensory substitution to support the translation of existing and new music, and some of the design challenges encountered throughout the development process. Results of a series of experiments conducted to assess the effectiveness of the MHC are discussed, followed by an overview of future directions for this research.

Urgency is a non-monotonic function of pulse rate

Magnitude estimation was used to assess the experience of urgency in pulse-train stimuli (pulsed white noise) ranging from 3.13 to 200 Hz. At low pulse rates, pulses were easily resolved. At high pulse rates, pulses fused together leading to a tonal sensation with a clear pitch level. Urgency ratings followed a nonmonotonic (polynomial) function with local maxima at 17.68 and 200 Hz. The same stimuli were also used in response time and pitch scaling experiments. Response times were negatively correlated with urgency ratings. Pitch scaling results indicated that urgency of pulse trains is mediated by the perceptual constructs of speed and pitch.