Recent research has begun measuring auditory working memory with a continuous adjustment task in which listeners adjust attributes of a sound to match a stimulus presented earlier. This approach captures auditory memory\'s continuous nature better than standard change detection paradigms that collect binary (\"same or different\") memory measurements. In two experiments, we assessed the impact of different interference stimuli (multitone complexes vs. white noise vs. silence) on the precision and accuracy of participants\' reproductions of pitch from memory. Participants were presented with a target multitone complex stimulus followed by eight successive interference signals. Across trials, these signals alternated between additional multitone complexes, randomly generated white noise samples, or (in Experiment 2) silence. This was followed by a response period where participants adjusted the pitch of a response stimulus using a MIDI touchpad to match the target. Experiment 1 found a significant effect of interference type on performance, with tone interference signals producing the greatest impairments to participants\' accuracy and precision compared to white noise. Interestingly, it also found a compression in the participants\' responses, with overestimations of low-frequency targets and underestimations for high-frequency targets. Experiment 2 replicated results from Experiment 1, with an additional silence condition showing the best performance, suggesting that non-tonal signals also generate interference. In general, results support a shared resource model of working memory with a limited capacity that can be flexibly allocated to hold items in memory with varying levels of fidelity. Interference does not appear to knock items out of a fixed precision slot, but rather robs a portion of capacity from stored items.

Interactive vocal communication, similar to a human conversation, requires flexible and real-time changes to vocal output in relation to preceding auditory stimuli. These vocal adjustments are essential to ensuring both the suitable timing and content of the interaction. Precise timing of dyadic vocal exchanges has been investigated in a variety of species, including humans. In contrast, the ability of non-human animals to accurately adjust specific spectral features of vocalization extemporaneously in response to incoming auditory information is less well studied. One spectral feature of acoustic signals is the fundamental frequency, which we perceive as pitch. Many animal species can discriminate between sound frequencies, but real-time detection and reproduction of an arbitrary pitch have only been observed in humans. Here, we show that nightingales in the wild can match the pitch of whistle songs while singing in response to conspecifics or pitch-controlled whistle playbacks. Nightingales matched whistles across their entire pitch production range indicating that they can flexibly tune their vocal output along a wide continuum. Prompt whistle pitch matches were more precise than delayed ones, suggesting the direct mapping of auditory information onto a motor command to achieve online vocal replication of a heard pitch. Although nightingales\' songs follow annual cycles of crystallization and deterioration depending on breeding status, the observed pitch-matching behavior is present year-round, suggesting a stable neural circuit independent of seasonal changes in physiology. Our findings represent the first case of non-human instantaneous vocal imitation of pitch, highlighting a promising model for understanding sensorimotor transformation within an interactive context. VIDEO ABSTRACT.

OBJECTIVE: Pitch perception distortion (PPD) is a novel term describing a phenomenon in which an amplified, accompanied singer\'s perception of their sung pitch relative to band or accompaniment becomes ambiguous, leading to one of two conditions: a) the singer believes they are out of tune with the accompaniment, but are in tune as perceived by a listener, or b) the singer believes they are in tune with the accompaniment, but are not. This pilot study aims to investigate the existence and incidence of PPD among amplified, accompanied performers and identify associated variables.
METHODS: 115 singers were recruited to participate in an online survey, which collected information on musical training, performance environment, and PPD experience.
RESULTS: Reported PPD incidence was 68%, with 92% of respondents indicating that PPD occurred rarely. The factors reported as most associated with PPD experiences included loud stage volume, poor song familiarity, singing outside one\'s habitual pitch range, and singing loudly. Contrary to previous studies and our hypotheses, no association was found between modality of auditory feedback (e.g., in-ears versus floor monitors) and incidence of PPD. Additionally, higher levels of training were found to be associated with higher incidence of PPD.
CONCLUSIONS: The reported incidence supports that PPD exists beyond chance and anecdotal experience. In light of the highly trained sample, the data suggest that pitch accuracy in accompanied, amplified performance may be more associated with aural environment-specifically loud stage volume-and a highly trained singer\'s tuning strategy in response to that environment rather than a singer\'s mastery of vocal intonation skills in isolation. Loud stage volume was implicated as a primary factor associated with PPD, which may be related to the stapedius reflex. Future investigations will target attempted elicitation of PPD in trained singers after establishing baseline auditory reflex thresholds and objective measurements of intonation accuracy.

OBJECTIVE: Pitch perception is an important part of accurate singing. Therefore, accurate singing requires the ability to accurately assess the pitch in one\'s own voice.There are two objectives of this study the first was to investigate whether there is a measurable difference in perceived pitch in one\'s voice to the pitch one perceives from an external sound source. The second, to measure the effects of occlusion on pitch accuracy over a melodic phrase.
METHODS: We recruited 16 participants for this study. The study that was designed to investigate the perceptual difference was split into two parts. The first is a one-to-one pitch matching test where they would recreate a pitch with singing and matching external pitches. The second was singing the familiar song \'Happy Birthday\' which was used to measure pitch accuracy over a melodic phrase and to measure the effects of occlusion on pitch accuracy while singing.
METHODS: The one-to-one study involved singing back a series of 5 notes to a set vowel which were the same 5 notes used when matching them to a series of possible pitches on the button test. The melodic test was to sing \'Happy Birthday\' 3 times, the first normally, the second wearing headphones to occlude the ear to reduce air conductive hearing and the third time with white noise to mask all hearing.
RESULTS: The results showed a higher accuracy of pitch matching with external sounds over using their voice, and some form of occlusion (wearing headphones or headphones with white noise) showed the version with higher pitch accuracy.
CONCLUSIONS: The results of this study showed that there was improved pitch accuracy when comparing two external sounds in pitch and when singing occlusion of some form improved pitch accuracy. This could suggest a difference when recreating pitch between the voice and matching external sound sources. Furthermore, with the improvements shown from occluding the ears, it could further suggest a difference in pitch perception abilities between the voice and external sound sources. This could have implications of improving pitch accuracy in a studio environment.

Two-electrode stimuli presented on adjacent mid-array contacts in cochlear-implant users elicit pitch percepts that are not consistent with a summation of the two temporal patterns. This indicates that low-rate temporal rate codes can be applied with considerable independence on adjacent mid-array electrodes. At issue in this study was whether a similar independence of temporal pitch cues can also be observed for more apical sites of stimulation, where temporal cues have been shown to be more reliable than place cues, in contrast to middle and basal sites. In cochlear-implant recipients with single-sided deafness implanted with long lateral-wall electrode arrays, pitch percepts were assessed by matching the pitch of dual-electrode stimuli with pure tones presented to the contralateral normal-hearing ear. The results were supported with an additional pitch-ranking experiment, in a different subject population with bilateral deafness. Unmodulated pulse trains with 100, 200, and 400 pulses per second were presented on three pairs of adjacent electrodes. Pulses were separated by the minimal interchannel delay (1.7 µs) in a short-delay configuration and by half the pulse period in a long-delay configuration. The hypothesis was that subjects would perceive a pitch corresponding to the doubled temporal pattern for the long-delay stimuli due to the summation of excitation patterns from adjacent apical electrodes, if those electrodes were to activate largely overlapping neural populations. However, we found that the mean matched acoustic pitch of the long-delay pulses was not significantly different from that of the short-delay pulses. These findings suggest that also in the apical region in long-array cochlear-implant recipients, temporal cues can be transmitted largely independently on adjacent electrodes.

Tinnitus assessment is a precursor for individualized treatment and outcome measurement. In the recent years, several studies proposed two-alternative forced choice (2AFC) recursive matching as a method to determine tinnitus pitch-match frequency in a standardized reliable manner. Currently, pure tones are used as comparison stimuli to assess pitch-match frequency. In this study, we investigated the psychometric quality of the method comparing different sound types. We measured 20 chronic tinnitus patients in 2 runs on 3 days. To assess pitch-match frequency, we used 2AFC recursive matching and compared results between pure tones and narrow band noise (NBN). Test-retest reliability between runs and across sound types was high (α>0.9) and increased across days. Perceived matching difficulty and time to completion decreased over repetitions. Importantly, the difference of matched frequencies (DMF) between runs was significantly less for NBN. When patients matched the spectral bandwidth of a test tone to their tinnitus, consistency was high (α=0.86) and no patient indicated continuously a pure tone. In conclusion, we recommend using NBN sounds in 2AFC recursive matching to assess pitch-match frequency as a standardized reliable method. Such a procedure could be offered as smartphone-based application to monitor tinnitus symptomatology for individualized assessment and treatment outcome.

BACKGROUND: Pitch perception and pitch matching may link to individual reading skills.
OBJECTIVE: In this study, we examined pitch perception and pitch matching tasks in children with learning disabilities to determine whether there was any connection between these tests and the reading fluency in these children.
METHODS: The study used different types of pitch discrimination tests and reading fluency tests to compare the two groups.
RESULTS: Results indicated that the accuracy of pitch discrimination and reading fluency was significantly different in these children with learning disabilities relative to typically developing children. This study also indicated that they exhibit impaired pitch matching, which linked to their reading skills.
CONCLUSIONS: The results indicate that processing and production of speech may be impacted by individuals\' musical pitch perception and matching ability. The results may also give us a piece of evidence that we need further research on how these deficits in musical pitch perception affect our speech and language production in children and adults.

The determination of the tinnitus pitch-match (PM) frequency is not straightforward but an important audiological assessment recommended for clinical and research purposes. We evaluated repetitive recursive matching using an iPod-based matching procedure as a method to estimate a patient\'s PM frequency without audiometric equipment.
One hundred and seventeen patients with chronic tonal tinnitus (uni- and bilateral tinnitus) measured their tinnitus in 10 sessions using a self-administered automated iPod-based procedure comprising a recursive 2 interval forced-choice test.
Mean SD of the PM frequency of all participants across sessions was 0.41 octaves. The internal consistency measured by Cronbach\'s α was very high (0.8->0.95). As an example, 7 PMs obtained excellent internal consistency (α = 0.93). The exclusion of the first and/or second session led to more definite PMs with a decreased SD. Outliers were identified by PMs departing 2 SDs (i.e., 0.94 octaves) from the mean variability (n = 5).
Repetitive recursive matching together with recommendations for the exclusion of initial and redundant sessions as well as outlier identification and treatment can enable a reliable estimation of the PM frequency.

There is often a mismatch for bilateral cochlear implant (CI) users between the electrodes in the two ears that receive the same frequency allocation and the electrodes that, when stimulated, yield the same pitch. Studies with CI users who have extreme mismatches between the two ears show that adaptation occurs in terms of pitch matching, reducing the difference between which electrodes receive the same frequency allocation and which ones produce the same pitch. The considerable adaptation that occurs for these extreme cases suggests that adaptation should be sufficient to overcome the relatively minor mismatches seen with typical bilateral CI users. However, even those with many years of bilateral CI use continue to demonstrate a mismatch. This may indicate that adaptation only occurs when there are large mismatches. Alternatively, it may indicate that adaptation occurs regardless of the magnitude of the mismatch, but that adaptation is proportional to the magnitude of the mismatch, and thus never fully counters the original mismatch. To investigate this, six bilateral CI users with initial pitch-matching mismatches of less than 3 mm completed a pitch-matching task near the time of activation, 6 months after activation, and 1 year after activation. Despite relatively small initial mismatches, the results indicated that adaptation still occurred.

Perceiving and producing vocal sounds are important functions of the auditory-motor system and are fundamental to communication. Prior studies have identified a network of brain regions involved in pitch production, specifically pitch matching. Here we reverse engineer the function of the auditory perception-production network by targeting specific cortical regions (e.g., right and left posterior superior temporal (pSTG) and posterior inferior frontal gyri (pIFG)) with cathodal transcranial direct current stimulation (tDCS)-commonly found to decrease excitability in the underlying cortical region-allowing us to causally test the role of particular nodes in this network. Performance on a pitch-matching task was determined before and after 20 min of cathodal stimulation. Acoustic analyses of pitch productions showed impaired accuracy after cathodal stimulation to the left pIFG and the right pSTG in comparison to sham stimulation. Both regions share particular roles in the feedback and feedforward motor control of pitched vocal production with a differential hemispheric dominance.