Pitch discrimination is better for synthetic timbre than natural musical instrument timbres, despite familiarity

Pitch discrimination is better for complex tones than for pure tones, but how more subtle differences in timbre affect pitch discrimination is not fully understood. This study compared pitch discrimination thresholds of flat-spectrum harmonic complex tones with those of natural sounds played by musical instruments of three different timbres (violin, trumpet, and flute). To investigate whether natural familiarity with sounds of particular timbres affects pitch discrimination thresholds, this study recruited musicians who were trained on one of the three instruments. We found that flautists and trumpeters could discriminate smaller differences in pitch for artificial flat-spectrum tones, despite their unfamiliar timbre, than for sounds played by musical instruments, which are regularly heard in everyday life (particularly by musicians who play those instruments). Furthermore, thresholds were no better for the instrument a musician was trained to play than for other instruments, suggesting that even extensive experience listening to and producing sounds of particular timbres does not reliably improve pitch discrimination thresholds for those timbres. The results show that timbre familiarity provides minimal improvements to auditory acuity, and physical acoustics (i.e., the presence of equal-amplitude harmonics) determine pitch-discrimination thresholds more than does experience with natural sounds and timbre-specific training.

The Influence of the Psychophysical Assessment Paradigm on Pitch Discrimination for Adults (and a Pilot Sample of Children)

Pitch discrimination ability has been of research interest due to its potential relationship to language and literacy. However, assessment protocols for pitch discrimination have varied widely. Prior studies with both children and adults have produced conflicting performance findings across different pitch discrimination research paradigms, though they have consistently shown that discrimination accuracy is based on the psychophysical assessment method applied. In the present study, we examined pitch discrimination performance among convenience samples of 19 adult women and ten female children across six different adaptive psychophysical measurement conditions. We found pitch discrimination performance in both groups to be impacted by the measurement paradigm such that, while adults exhibited significantly better discrimination thresholds than did children, the pattern of performance across the six conditions was similar for both the adults and the children.

A Preliminary Exploration of Pitch Discrimination, Temporal Sequencing, and Prosodic Awareness Skills of Children Who Participate in Different School-Based Music Curricula

Musical training has been shown to have a positive influence on a variety of skills, including auditory-based tasks and nonmusical cognitive and executive functioning tasks; however, because previous investigations have yielded mixed results regarding the relationship between musical training and these skills, the purpose of this study was to examine and compare the auditory processing skills of children who receive focused, daily musical training with those with more limited, generalized musical training. Sixteen typically developing children (second–fourth grade) from two different schools receiving different music curricula were assessed on measures of pitch discrimination, temporal sequencing, and prosodic awareness. The results indicated significantly better scores in pitch discrimination abilities for the children receiving daily, focused musical training (School 1) compared to students attending music class only once per week, utilizing a more generalized elementary school music curriculum (School 2). The findings suggest that more in-depth and frequent musical training may be associated with better pitch discrimination abilities in children. This finding is important given that the ability to discriminate pitch has been linked to improved phonological processing skills, an important skill for developing spoken language and literacy. Future investigations are needed to determine whether the null findings for temporal sequencing and prosodic awareness can be replicated or may be different for various grades and tasks for measuring these abilities.

Perception and learning of relative pitch by musicians using the vibrotactile mode

This study investigated the perception and learning of relative pitch using vibrotactile stimuli by musicians with and without a hearing impairment. Notes from C3 to B4 were presented to the fingertip and forefoot. Pre- and post-training tests in which 420 pairs of notes were presented randomly were carried out without any feedback to participants. After the pre-training test, 16 short training sessions were carried out over six weeks with 72 pairs of notes per session and participants told whether their answers were correct. For amateur and professional musicians with normal hearing and professional musicians with a severe or profound hearing loss, larger pitch intervals were easier to identify correctly than smaller intervals. Musicians with normal hearing had a high success rate for relative pitch discrimination as shown by pre- and post-training tests, and when using the fingertips, there was no significant difference between amateur and professional musicians. After training, median scores on the tests in which stimuli were presented to the fingertip and forefoot were >70% for intervals of 3–12 semitones. Training sessions reduced the variability in the responses of amateur and professional musicians with normal hearing and improved their overall ability. There was no significant difference between the relative pitch discrimination abilities between one and 11 semitones, as shown by the pre-training test, of professional musicians with and without a severe/profound hearing loss. These findings indicate that there is potential for vibration to be used to facilitate group musical performance and music education in schools for the deaf.

No interaction between fundamental-frequency differences and spectral region when perceiving speech in a speech background

Differences in fundamental frequency (F0) or pitch between competing voices facilitate our ability to segregate a target voice from interferers, thereby enhancing speech intelligibility. Although lower-numbered harmonics elicit a stronger and more accurate pitch sensation than higher-numbered harmonics, it is unclear whether the stronger pitch leads to an increased benefit of pitch differences when segregating competing talkers. To answer this question, sentence recognition was tested in young normal-hearing listeners in the presence of a single competing talker. The stimuli were presented in a broadband condition or were highpass or lowpass filtered to manipulate the pitch accuracy of the voicing, while maintaining roughly equal speech intelligibility in the highpass and lowpass regions. Performance was measured with average F0 differences (ΔF0) between the target and single-talker masker of 0, 2, and 4 semitones. Pitch discrimination abilities were also measured to confirm that the lowpass-filtered stimuli elicited greater pitch accuracy than the highpass-filtered stimuli. No interaction was found between filter type and ΔF0 in the sentence recognition task, suggesting little or no effect of harmonic rank or pitch accuracy on the ability to use F0 to segregate natural voices, even when the average ΔF0 is relatively small. The results suggest that listeners are able to obtain some benefit of pitch differences between competing voices, even when pitch salience and accuracy is low. The accuracy with which we are able to discriminate the pitch of a harmonic complex tone depends on the F0 and the harmonic numbers present. For F0s in the average range of speech (100–200 Hz), pitch discrimination is best (implying accurate F0 coding) when harmonics below about the 10th are present [6–10]. When these lower-numbered harmonics are present, pitch discrimination is also independent of the phase relationships between the harmonics, suggesting that these harmonics are spectrally resolved to some extent. In contrast, when only harmonics above the 10th are present in this range of F0s, pitch discrimination is poorer and is affected by the phase relationships between harmonics, suggesting that interactions occur between these spectrally unresolved harmonics [6–10]. Psychoacoustic studies of sound segregation have often been carried out with interleaved sequences of tones. Some of these studies have investigated segregation based on differences in pitch accuracy and have varied the accuracy by systematically varying whether resolved or only unresolved harmonics are present. Previous studies have found that stream segregation can occur with alternating sequences of tones, even if the tones consist only of unresolved harmonics [11–14]. However, the question of whether streaming is greater with resolved than unresolved harmonics has received mixed answers. In cases where the listeners’ task was to segregate the streams, some studies have shown little difference in streaming between conditions containing resolved or only unresolved harmonics [11, 15], whereas another study using a similar approach found significantly greater stream segregation when resolved harmonics were present than when only unresolved harmonics were present [12]. However, in situations where the task was either neutral or encouraged listeners to integrate the sequences into a single stream, the results have been consistent across studies in showing greater segregation for complex tones containing resolved harmonics than for tones containing only unresolved harmonics [13, 14]. These findings support the idea that pitch accuracy can affect our ability to segregate sounds. Less is known about the role of low-numbered harmonics in the context of segregating competing speech. Bird and Darwin [2] showed that lower harmonics dominate performance in a speech-segregation task based on F0 differences, but they did not test any conditions containing only high-numbered harmonics. Oxenham and Simonson [16] explored the effect of harmonic rank on speech intelligibility by comparing conditions where the target and single-talker masker had been lowpass (LP) or highpass (HP) filtered to either retain (LP-filtered) or remove (HP-filtered) the spectrally resolved components from the target and masker [16]. The LP and HP cutoff frequencies were selected to produce roughly equal performance in noise for both conditions. Surprisingly, performance in the LP and HP conditions improved by similar amounts when the noise masker was replaced by a single-talker masker with a different average F0, suggesting no clear benefit of having resolved harmonic components in the speech. However, that study only used relatively large values of average ΔF0 that according to recent F0 estimates were approximately 4 and 8 semitones (ST). Moreover, this study did not parametrically vary the ΔF0 between the target and masker. It may be that pitch accuracy is only relevant for more challenging conditions, i.e. for conditions with smaller average values of ΔF0. Thus, it remains unclear whether the effect of ΔF0 on performance is affected by the presence or absence of low-numbered, spectrally resolved harmonics. The aim of the present study was to determine whether there is an effect of spectral region, and hence pitch coding accuracy, on the ability of listeners to use average F0 differences between a target and an interfering talker to understand natural speech.

Audiovisual structural connectivity in musicians and non-musicians: a cortical thickness and diffusion tensor imaging study

Our sensory systems provide complementary information about the multimodal objects and events that are the target of perception in everyday life. Professional musicians’ specialization in the auditory domain is reflected in the morphology of their brains, which has distinctive characteristics, particularly in areas related to auditory and audio-motor activity. Here, we combined diffusion tensor imaging (DTI) with a behavioral measure of visually induced gain in pitch discrimination, and we used measures of cortical thickness (CT) correlations to assess how auditory specialization and musical expertise are reflected in the structural architecture of white and grey matter relevant to audiovisual processing. Across all participants (n = 45), we found a correlation (p < 0.001) between reliance on visual cues in pitch discrimination and the fractional anisotropy (FA) in the left inferior fronto-occipital fasciculus (IFOF), a structure connecting visual and auditory brain areas. Group analyses also revealed greater cortical thickness correlation between visual and auditory areas in non-musicians (n = 28) compared to musicians (n = 17), possibly reflecting musicians’ auditory specialization (FDR < 10%). Our results corroborate and expand current knowledge of functional specialization with a specific focus on audition, and highlight the fact that perception is essentially multimodal while uni-sensory processing is a specialized task.

The Contribution of Frequency Discrimination Ability to Auditory Temporal Patterning Tests in Children

Purpose The Pitch Patterns Test (PPT) and the Duration Patterns Test (DPT) are clinical auditory processing tests that evaluate temporal patterning skills based on pitch (PPT) or duration (DPT) aspects of sound. Although temporal patterning tests are categorized under the temporal processing domain, successful performance on the PPT also relies on accurate pitch discrimination. However, the relationship between pitch discrimination ability and temporal patterning skills has not been thoroughly evaluated. This study examined the contribution of pitch discrimination ability to performance on temporal patterning in children through the use of a pitch discrimination task and the PPT. The DPT was also given as a control measure to assess temporal patterning with no pitch component. Method Thirty-two typically developing elementary school–age children (6;11–11;3 [years;months]) with normal hearing were given a series of three counterbalanced tasks: an adaptive psychophysical pitch discrimination task (difference limen for frequency [DLF]), the PPT, and the DPT. Results Correlational analysis revealed moderate correlations between DLF and PPT scores. After accounting for age, results of a linear regression analysis suggested that pitch discrimination accounts for a significant amount of variance in performance on the PPT. No significant correlation was found between DLF and DPT scores, supporting the hypothesis that the pitch task had no significant temporal patterning component contributing to the overall score. Discussion These findings indicate that pitch discrimination contributes significantly to performance on the PPT, but not the DPT, in a typically developing pediatric population. This is an important clinical consideration in both assessment and utilization of targeted therapy techniques for different clinical populations.

Infants can outperform adults in pitch and timbre perception

Adults perceive pitch with fine precision, an ability ascribed to cortical functions that are also important for speech and music perception. Infants display neural immaturity in the auditory cortex, suggesting that pitch discrimination may improve throughout infancy. In three experiments, we tested the limits of pitch and timbre perception in 66 infants and 44 adults. Contrary to expectations, we found that infants surpassed adults in detecting subtle changes in pitch in the presence of random variations in timbre, and vice versa. The results indicate high fidelity of pitch and timbre coding in infants, implying that fully mature cortical processing is not necessary for accurate discrimination of these features. The surprising superiority of infants over adults may reflect a developmental trajectory for learning natural statistical covariations between pitch and timbre that improves coding efficiency in adults, but results in degraded perceptual acuity when expectations for such covariations are violated.