Cochlear implants are medical devices that have restored hearing to approximately one million people around the world. Outcomes are impressive and most recipients attain excellent speech comprehension in quiet without relying on lip-reading cues, but pitch resolution is poor compared to normal hearing. Amplitude modulation of electrical stimulation is a primary cue for pitch perception in cochlear implant users. The experiments described in this article focus on the relationship between sensitivity to amplitude modulations and pitch resolution based on changes in the frequency of amplitude modulations. In the first experiment, modulation sensitivity and pitch resolution were measured in adults with no known hearing loss and in cochlear implant users with sounds presented to and processed by their clinical devices. Stimuli were amplitude-modulated sinusoids and amplitude-modulated narrow-band noises. Modulation detection and modulation frequency discrimination were measured for modulation frequencies centered on 110, 220, and 440 Hz. Pitch resolution based on changes in modulation frequency was measured for modulation depths of 25 %, 50 %, 100 %, and for a half-waved rectified modulator. Results revealed a strong linear relationship between modulation sensitivity and pitch resolution for cochlear implant users and peers with no known hearing loss. In the second experiment, cochlear implant users took part in analogous procedures of modulation sensitivity and pitch resolution but bypassing clinical sound processing using single-electrode stimulation. Results indicated that modulation sensitivity and pitch resolution was better conveyed by single-electrode stimulation than by clinical processors. Results at 440 Hz were worse, but also not well conveyed by clinical sound processing, so it remains unclear whether the 300 Hz perceptual limit described in the literature is a technological or biological limitation. These results highlight modulation depth and sensitivity as critical factors for pitch resolution in cochlear implant users and characterize the relationship that should inform the design of modulation enhancement algorithms for cochlear implants.

BACKGROUND: Rehabilitation of hearing and listening difficulties through neuroplasticity of the auditory nervous system is a promising technique. Evidence of enhanced auditory processing in adult musicians is often not based on clinical auditory processing tests and is lacking in children with musical education.
OBJECTIVE: The aim of this study is to investigate the temporal resolution and frequency discrimination elements of auditory processing both in adults and children with musical education and to compare them with those without any musical education.
METHODS: Participants consisted of ten children without musical training and ten children with musical training with mean age 11.3 years and range 8-15 years as well as ten adults without musical education and ten adults with musical education with mean age 38.1 years and range 30-45 years. All participants were tested with two temporal resolution tests (GIN:Gaps-In-Noise and RGDT:Random Gap Detection Test), a temporal ordering frequency test (FPT:Frequency Pattern Test), and a frequency discrimination test (DLF: Different Limen for Frequency).
RESULTS: All test results revealed better performance in both children and adults with musical training for both ears.
CONCLUSIONS: A positive effect of formal music education for specific auditory processing elements in both children and adults is documented. Larger samples, longitudinal studies, as well as groups with impaired hearing and/or auditory processing are needed to further substantiate the effect shown.

There is an increasing body of evidence suggesting that there are low-level perceptual processes involved in crossmodal correspondences. In this study, we investigate the involvement of the superior colliculi in three basic crossmodal correspondences: elevation/pitch, lightness/pitch, and size/pitch. Using a psychophysical design, we modulate visual input to the superior colliculus to test whether the superior colliculus is required for behavioural crossmodal congruency effects to manifest in an unspeeded multisensory discrimination task. In the elevation/pitch task, superior colliculus involvement is required for a behavioural elevation/pitch congruency effect to manifest in the task. In the lightness/pitch and size/pitch task, we observed a behavioural elevation/pitch congruency effect regardless of superior colliculus involvement. These results suggest that the elevation/pitch correspondence may be processed differently to other low-level crossmodal correspondences. The implications of a distributed model of crossmodal correspondence processing in the brain are discussed.

This study investigated whether the interference between two tasks in dual-task processing stems from bottleneck limitations or insufficient cognitive resources due to resource sharing. Experiment 1 used tone discrimination as Task 1 and word or pseudoword classification as Task 2 to evaluate the effect of automatic versus controlled processing on dual-task interference under different SOA conditions. Experiment 2 reversed the task order. The results showed that dual-task interference persisted regardless of task type or order. Neither experiment found evidence that automatic tasks could eliminate interference. This suggests that resource limitations, rather than bottlenecks, may better explain dual-task costs. Specifically, when tasks compete for limited resources, the processing efficiency of both tasks is significantly reduced. Future research should explore how cognitive resources are dynamically allocated between tasks to better account for dual-task interference effects.

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.

Musicians display a variety of auditory perceptual benefits relative to people with little or no musical training; these benefits are collectively referred to as the \"musician advantage.\" Importantly, musicians consistently outperform nonmusicians for tasks relating to pitch, but there are mixed reports as to musicians outperforming nonmusicians for timbre-related tasks. Due to their experience manipulating the timbre of their instrument or voice in performance, we hypothesized that musicians would be more sensitive to acoustic context effects stemming from the spectral changes in timbre across a musical context passage (played by a string quintet then filtered) and a target instrument sound (French horn or tenor saxophone; Experiment 1). Additionally, we investigated the role of a musician\'s primary instrument of instruction by recruiting French horn and tenor saxophone players to also complete this task (Experiment 2). Consistent with the musician advantage literature, musicians exhibited superior pitch discrimination to nonmusicians. Contrary to our main hypothesis, there was no difference between musicians and nonmusicians in how spectral context effects shaped instrument sound categorization. Thus, musicians may only outperform nonmusicians for some auditory skills relevant to music (e.g., pitch perception) but not others (e.g., timbre perception via spectral differences).

Harmonic complex tones are easier to detect in noise than inharmonic complex tones, providing a potential perceptual advantage in complex auditory environments. Here, we explored whether the harmonic advantage extends to other auditory tasks that are important for navigating a noisy auditory environment, such as amplitude- and frequency-modulation detection. Sixty young normal-hearing listeners were tested, divided into two equal groups with and without musical training. Consistent with earlier studies, harmonic tones were easier to detect in noise than inharmonic tones, with a signal-to-noise ratio (SNR) advantage of about 2.5 dB, and the pitch discrimination of the harmonic tones was more accurate than that of inharmonic tones, even after differences in audibility were accounted for. In contrast, neither amplitude- nor frequency-modulation detection was superior with harmonic tones once differences in audibility were accounted for. Musical training was associated with better performance only in pitch-discrimination and frequency-modulation-detection tasks. The results confirm a detection and pitch-perception advantage for harmonic tones but reveal that the harmonic benefits do not extend to suprathreshold tasks that do not rely on extracting the fundamental frequency. A general theory is proposed that may account for the effects of both noise and memory on pitch-discrimination differences between harmonic and inharmonic tones.

The study objective was to characterize cochlear implant (CI) pitch perception for pure, complex, and modulated tones for frequencies and fundamental frequencies in the ecologically essential range between 110 and 440 Hz. Stimulus manipulations were used to examine CI users\' reliance on stimulation place and rate cues for pitch discrimination.
The study was a within-subjects design with 21 CI users completing pitch discrimination measures using pure, complex, and modulated tones. Stimulus manipulations were used to test whether CI users have better pitch discrimination for low-pass compared with high-pass filtered harmonic complexes, and to test whether they have better pitch discrimination when provided a covarying place cue when listening to amplitude-modulated tones.
Averaged across conditions, participants had better pitch discrimination for pure tones compared with either complex or amplitude-modulated tones. Participants had better pitch discrimination for low-pass compared with high-pass harmonic complexes and better pitch discrimination for amplitude-modulated tones when provided a covarying place cue.
CI users integrate place and rate cues across the ecologically essential pitch range between 110 and 440 Hz. We interpret the observed better pitch discrimination for low-pass compared with high-pass filtered harmonics complexes, and for amplitude-modulated tones when provided a covarying place cue, as evidence for the importance of providing place-of-excitation cues for fundamental frequencies below 440 Hz. Discussion considers how such encoding could be implemented with existing devices.

In the present paper, we carry out a replication of a seminal paper by Kahneman, D. & Beatty, J. (1967). Perception & Psychophysics, 2(3),101-105 for using pupillometry as an implicit measure of auditory processing load, specifically, non-verbal auditory processing. While numerous papers since have supported the notion that pupillometry is a fairly reliable index of processing load in general  (Zekveld, A. A., Koelewijn, T., and Kramer, S. E. (2018). Trends in Hearing, 22,1-25; Winn, M. B., Wendt, D., Koelewijn, T., and Kuchinsky, S. E. (2018). Trends in Hearing, 22,1-32), they typically have relied on memory recall, and/or more sophisticated cognitive tasks such as language comprehension or split attention. Kahneman and Beatty\'s paper, despite that it was published more than 50 years ago, continues to be the primary citation to support the claim that pupillometry is a reliable index of task difficulty for a simple non-verbal pitch discrimination task therefore giving us an implicit measure for listening effort (e.g.,Kramer, S. E., Lorens, A., Coninx, F., Zekveld, A. A., Piotrowska, A., & Skarzynski, H. (2013). Language and Cognitive Processes, 28(4),426-442; Schlemmer, K. B., Kulke, F., Kuchinke, L., & Van Der Meer, E. (2005). Psychophysiology, 42(4),465-472; Lisi, M., Bonato, M., and Zorzi, M. (2015). Biological Psychology, 112,39-45). This type of task takes very little explicit memory, is non-verbal, and relies heavily on more low-level, automatic perceptual processing. Using two different replication studies, one exact, and one modified, we only replicated the main result in the modified replication. The true replication failed to replicate on all nine statistical tests. Overall, our findings suggest that pupil dilation can be used as an implicit measure of task difficulty for a simple, non-semantic, auditory task, however, the robustness of the effect appears relatively weak in comparison with the original study, and the amount of variation across participants much greater.

OBJECTIVE: Music is a highly complex acoustic stimulus in both spectral and temporal contents. Accurate representation and delivery of high-fidelity information are essential for music perception. However, it is unclear how well bone-anchored hearing implants (BAHIs) transmit music. The study objective is to establish music perception performance baselines for BAHI users and normal hearing (NH) listeners and compare outcomes between the cohorts.
METHODS: A case-controlled, cross-sectional study was conducted among 18 BAHI users and 11 NH controls. Music perception was assessed via performance on seven major musical element tasks: pitch discrimination, melodic contour identification, rhythmic clocking, basic tempo discrimination, timbre identification, polyphonic pitch detection, and harmonic chord discrimination.
RESULTS: BAHI users performed comparably well on all music perception tasks with their device compared with the unilateral condition with their better-hearing ear. BAHI performance was not statistically significantly different from NH listeners\' performance. BAHI users performed just as well, if not better than NH listeners when using their control contralateral ear; there was no significant difference between the two groups except for the rhythmic timing (BAHI non-implanted ear 69% [95% CI: 62%-75%], NH 56% [95% CI: 49%-63%], p = 0.02), and basic tempo tasks (BAHI non-implanted ear 80% [95% CI: 65%-95%]; NH 75% [95% CI: 68%-82%, p = 0.03]).
CONCLUSIONS: This study represents the first comprehensive study of basic music perception performance in BAHI users. Our results demonstrate that BAHI users perform as well with their implanted ear as with their contralateral better-hearing ear and NH controls in the major elements of music perception.
METHODS: 3 Laryngoscope, 134:1381-1387, 2024.