Exploring Pitch Perception Thresholds in Very Short Tones: Minimum Tone Duration for Perception of Pitch in 2-Tone and 3-Tone Sequences

Abstract

To teach students the elements of music, comprehensive understanding of each element is essential. The thesis aimed to improve understanding of pitch perception in short contiguous tone sequences. A study with 20 first-year psychology students established that the ability to order tones does not mean their pitch can be identified. With timbre varied between stimuli, longer durations were required to identify the order of 2-tone sequences, compared to when timbre was the same for all stimuli ( p < .01, effect size = 0.72). It was concluded that identification of the shortest stimuli relied on sound analogue comparison (holistic representations of sound sequences), not pitch perception. A method to establish the Minimum Duration for Perception of Pitch (MDPP) in short contiguous tone sequences was created using target and test tones of different timbre and duration. Tone durations under 40ms were asynchronously modified by frequency level with lower frequencies retaining longer durations. Using a 3-forced-choice paradigm, four experienced musicians (18-58 years; 3 males) matched short sine wave target tones against long piano test tones as either the same pitch, or a semitone higher or lower. Mean overall MDPP was 8ms for single tones, 24ms for 2-tone sequences and 47ms for 3-tone sequences. Results for single tones matched those from previous research. Minimum durations varied extensively, depending on each tone’s position in 2-tone and 3-tone sequences. Longer minimum durations were recorded to identify low compared to high tones in the first position of 2-tone sequence (13ms difference, 95% CI [1ms, 25ms], p = .043) and in both the first position (54ms difference, 95% CI [2ms, 104ms], p = .046.) and the second position (53ms difference, 95% CI [19ms, 88ms], p = .014) of 3-tone sequences. It was suggested that differences were caused by (i) preconscious adjustment of low tones to accommodate subsequent high tones as harmonics of the lower tones, causing identification errors in low tones; and (ii) stream segregation of higher tones, enabling easier identification of high tones. Tones positioned last were unaffected by the relative pitch of previous tones. Further work will be required to establish the duration at which the number of segments in a sequence of tones no longer affects the MDPP by increasing the number of segments until the average minimum duration of tone segments reaches asymptote. Results were used to select durational limits for an aural training program to teach students musical intervals. The program used temporal occlusion (the reduction of tone durations to improve focus and concentration) to improve interval recognition skills for the first four intervals of a major scale (tone durations 1 second--20ms). Participants were 84 Year 8 students (aged 12-14, music experience 2-5 years) The study compared the new program to the school’s current aural training program; both were computer-based, self-explanatory, and modified training activities based on success. The new method was not significantly better than the current program. Suggested improvements included creating targeted videos for explaining tasks, improving “game like” aspects and providing opportunities for person-to-person interaction.