Pitch Perception Research Articles

Baldwin as phonographer

ABSTRACT William Baldwin wrote a variety of kinds of books, but through them all he displayed his skills as a phonographer, as a writer of sound. Geoffrey Streamer’s story about hearing animals speak is the best known of these works, but Baldwin’s compilation of ‘sayings’ of philosophers, his ballading of The Song of Solomon on the model of Sternhold’s Psalm tunes, his noisy tour of Hell in his satire on the death of Bishop Paul III of Rome, the transcribed voices collected in A Mirror for Magistrates, and his ‘funerals’ for Edward VI are all sound-rich books. What is more, the sounds in these books are located sounds. They are associated with particular acoustic environments, and they challenge readers to place themselves imaginatively in those environments. In this respect, Baldwin’s phonographies resemble the art of contemporary sound artists like Brandon LaBelle in Acoustic Territories.

Modification of transformer coupled permeameter for frequency extension

A broadband and high-sensitivity permeability measurement system that covers 10 MHz–20 GHz was previously developed and named the transformer coupled permeameter (TC-Perm). This paper describes the modifications of the TC-Perm system to further extend the operation frequency range on both the high and low frequency sides. In the previous system, the high frequency limit was set by a large notch appearing at around 22 GHz, which was considered to be caused by the excitation of two unwanted modes. In the new system, the jig design was modified to have a back ground plane and vias to suppress these unwanted modes, which resulted in a clean transmission characteristic over the entire frequency range up to 44 GHz. The low frequency limit is determined by the noise figure (NF) of the vector network analyzer input, which was measured to be ∼35 dB in the previous system configuration. The new system employed a low noise amplifier and analog switches to improve the NF to be 2.7 dB below 100 MHz. As a result of these modifications, the operation frequency range of the new TC-Perm system was extended to cover 1 MHz–44 GHz, which is sufficient for characterizing magnetic materials used in noise suppression sheets targeting fifth-generation millimeter-wave (5G mmWave) wireless communication.

Theoretical Study of Rampwise DPWM Technique to Reduce Motor Acoustic Noise

Motor acoustic noise generated near living environments such as elevators and electric vehicles may cause discomfort. In order to reduce the acoustic noise, the switching frequency is set to the high side of the audible frequency range. In this case, however, the switching loss is increased. The conventional discontinuous PWM (DPWM) method is widely used since it can reduce the switching loss drastically. However, it produces larger acoustic noise than the conventional sinusoidal PWM method. The authors have previously proposed Rampwise DPWM techniqueh which can reduce both acoustic noise and switching loss. In this paper, the line-line voltage with the proposed Rampwise DPWM technique is expanded into a real-valued Fourier series, and the frequency characteristics are analyzed. It is theoretically confirmed that the rampwise part in the Rampwise DPWM technique can achieve reduction of motor acoustic noise. Furthermore, the reduction effect of motor acoustic noise with the Rampwise DPWM technique is theoretically and experimentally verified.

Neurophysiological time course of timbre-induced music-like perception.

Traditionally, pitch variation in a sound stream has been integral to music identity. We attempt to expand music's definition, by demonstrating that the neural code for musicality is independent of pitch encoding. That is, pitchless sound streams can still induce music-like perception and a neurophysiological hierarchy similar to pitched melodies. Previous work reported that neural processing of sounds with no-pitch, fixed-pitch, and irregular-pitch (melodic) patterns, exhibits a right-lateralized hierarchical shift, with pitchless sounds favorably processed in Heschl's gyrus (HG), ascending laterally to nonprimary auditory areas for fixed-pitch and even more laterally for melodic patterns. The objective of this EEG study was to assess whether sound encoding maintains a similar hierarchical profile when musical perception is driven by timbre irregularities in the absence of pitch changes. Individuals listened to repetitions of three musical and three nonmusical sound-streams. The nonmusical streams were comprised of seven 200-ms segments of white, pink, or brown noise, separated by silent gaps. Musical streams were created similarly, but with all three noise types combined in a unique order within each stream to induce timbre variations and music-like perception. Subjects classified the sound streams as musical or nonmusical. Musical processing exhibited right dominant α power enhancement, followed by a lateralized increase in θ phase-locking and spectral power. The θ phase-locking was stronger in musicians than in nonmusicians. The lateralization of activity suggests higher-level auditory processing. Our findings validate the existence of a hierarchical shift, traditionally observed with pitched-melodic perception, underscoring that musicality can be achieved with timbre irregularities alone.NEW & NOTEWORTHY EEG induced by streams of pitchless noise segments varying in timbre were classified as music-like and exhibited a right-lateralized hierarchy in processing similar to pitched melodic processing. This study provides evidence that the neural-code of musicality is independent of pitch encoding. The results have implications for understanding music processing in individuals with degraded pitch perception, such as in cochlear-implant listeners, as well as the role of nonpitched sounds in the induction of music-like perceptual states.

Does Binaural Stimulation Enhance Temporal Processing in Young Children?

Background and objective Temporal processing abilities help perceive signal changes over time. Efficient temporal processing is necessary for pitch perception, voice identification, and speech perception. It plays a significant role in language development. Internal redundancy of the central auditory nervous plays a role in processing sensory information. There is a need to gain more insights into the maturation of neural hardwiring that supports binaural temporal processing at a young age. The purpose of the present study was to evaluate the difference between monaural and binaural temporal processing in children aged 7-11 years. Methods Temporal processing was assessed using gap detection and temporal modulation transfer function (TMTF) tests. The tests were administered in 40 typically developing children with normal clinical auditory sensitivity. The maximum likelihood procedure (MLP), a MATLAB toolbox, was employed to deliver the stimulus. A multivariate analysis followed by post hoc analysis was performed to analyze the data. Results There was a significant difference between binaural and monoaural stimulation in children aged 7-11 years. However, there was no statistically significant difference between the right and left ears for gap detection threshold (GDT) and TMTF across all test frequencies. Conclusion Based on our findings, binaural stimulation enhances temporal processing in young children.

Superior broadband sound absorption in hierarchical ultralight graphene oxide aerogels achieved through emulsion freeze-casting

Ultra-lightweight aerogels have profound applications as advanced multi-functional sound-absorbing materials. At present, conventional aerogels are associated with pores with sizes too small for effective sound absorption in the audible range. In this work, we fabricated a hierarchically porous ultralight graphene oxide (GO) aerogel through a novel emulsion freeze-casting process of an air-in-water emulsion. Microstructural analysis of the aerogels reveals a hierarchical pore morphology consisting of highly inter-connected pores produced from the emulsion bubbles and the micro-pores produced by freeze-casting. Sound absorption measurements revealed that an aerogel with a surfactant-to-GO weight ratio of 1:1 displays an average absorption coefficient of up to 0.86 at a broadband frequency range between 250 Hz and 6300 Hz, a vast improvement by up to 58% as compared to conventional GO aerogels. Numerical microstructural models were developed to model the acoustic absorption phenomenon and understand the mechanisms behind enhanced sound absorption. These models identified the enhanced acoustic absorption as attributed to the increased air-wetting area as derived from the high reticulation rate in this hierarchical microstructure. Overall, we demonstrate the potential of leveraging the highly inter-dependent material-process-structure relationships of GO aerogel production to achieve hierarchical GO aerogels as advanced ultralight sound-absorbing materials.

Hearing in helmeted guineafowl (Numida meleagris): audiogram from 2Hz to 10kHz and localization acuity for brief noise bursts.

Behavioral hearing thresholds and noise localization acuity were determined using a conditioned avoidance/suppression procedure for three Helmeted guineafowl (Numida meleagris). The guineafowl responded to frequencies as low as 2Hz at 82.5dB SPL, and as high as 8kHz at 84.5dB SPL.At a level of 60dB SPL, their hearing range spanned 8.12 octaves (24.6Hz-6.86kHz). Like most birds, they do not hear sounds above 8kHz. However, the guineafowl demonstrated good low-frequency hearing (frequencies below 32Hz), showing thresholds that are more sensitive than both the peafowl and pigeon, both of which hear infrasound. It thus appears that infrasound perception may be more common than previously thought and may have implications for species that inhabit areas with wind energy facilities. The guineafowls' minimum audible angle for a 100-ms broadband noise burst was 13.8 °, at the median for birds and near the mean for mammals. Unlike in mammals, the small sample of bird species and limited representation of lifestyles do not yet allow for meaningful interpretations of the selective pressures or mechanisms that underlie their abilities to locate sound sources.

Antlion larvae localize long distant preys by a mechanism based on time difference.

Pit building antlions Euroleon nostras have been submitted to artificial cues in order to delineate their faculty to localize a prey. Series of propagating pulses in sand have been created from an extended source made of 10 piezoelectric transducers equally spaced on a line and located at a large distance from the pit. The envelope of each pulse encompasses six oscillations at a carrier frequency of 1250 Hz and up to eight oscillations at 1666 Hz. In one set of experiments, the first wave front is followed by similar wave fronts and the antlions respond to the cue by throwing sand in the opposite direction of the wave front propagation direction. In another set of experiments, the first wave front is randomly spatially structured while the propagation of the wave fronts inside the envelope of the pulse are not. In that case, the antlions respond less to the cue by throwing sand, and when they do, their sand throwing is more randomly distributed in direction. The finding shows that the localization of vibration signal by antlions are based on the equivalent for hearing animals of interaural time difference in which the onset has more significance than the interaural phase difference.

Talker adaptation or "talker" adaptation? Musical instrument variability impedes pitch perception.

Listeners show perceptual benefits (faster and/or more accurate responses) when perceiving speech spoken by a single talker versus multiple talkers, known as talker adaptation.While near-exclusively studied in speech and with talkers, some aspects of talker adaptation might reflect domain-general processes. Music, like speech, is a sound class replete with acoustic variation, such as a multitude of pitch and instrument possibilities. Thus, it was hypothesized that perceptual benefits from structure in the acoustic signal (i.e., hearing the same sound source on every trial) are not specific to speech but rather a general auditory response. Forty nonmusician participants completed a simple musical task that mirrored talker adaptation paradigms. Low- or high-pitched notes were presented in single- and mixed-instrument blocks. Reflecting both music research on pitch and timbre interdependence and mirroring traditional "talker" adaptation paradigms, listeners were faster to make their pitch judgments when presented with a single instrument timbre relative to when the timbre was selected from one of four instruments from trial to trial. A second experiment ruled out the possibility that participants were responding faster to the specific instrument chosen as the single-instrument timbre. Consistent with general theoretical approaches to perception, perceptual benefits from signal structure are not limited to speech.

High-order implicit time integration scheme with controllable numerical dissipation based on mixed-order Padé expansions

A single-step high-order implicit time integration scheme with controllable numerical dissipation at high frequencies is presented for the transient analysis of structural dynamic problems. The amount of numerical dissipation is controlled by a user-specified value of the spectral radius ρ∞ in the high frequency limit. Using this user-specified parameter as a weight factor, a Padé expansion of the matrix exponential solution of the equation of motion is constructed by mixing the diagonal and sub-diagonal expansions. An efficient time-stepping scheme is designed where systems of equations, similar in complexity to the standard Newmark method, are solved recursively. It is shown that the proposed high-order scheme achieves high-frequency dissipation, while minimizing low-frequency dissipation and period errors. The effectiveness of the provided dissipation control and the efficiency of the scheme are demonstrated by numerical examples. A simple guideline for the choice of the controlling parameter and time step size is provided. The source codes written in MATLAB and FORTRAN are available for download at: https://github.com/ChongminSong/HighOrderTimeIntegration.

Distribution of multiunit pitch responses recorded intracranially from human auditory cortex.

The perception of pitch is a fundamental percept, which is mediated by the auditory system, requiring the abstraction of stimulus properties related to the spectro-temporal structure of sound. Despite its importance, there is still debate as to the precise areas responsible for its encoding, which may be due to species differences or differences in the recording measures and choices of stimuli used in previous studies. Moreover, it was unknown whether the human brain contains pitch neurons and how distributed such neurons might be. Here, we present the first study to measure multiunit neural activity in response to pitch stimuli in the auditory cortex of intracranially implanted humans. The stimulus sets were regular-interval noise with a pitch strength that is related to the temporal regularity and a pitch value determined by the repetition rate and harmonic complexes. Specifically, we demonstrate reliable responses to these different pitch-inducing paradigms that are distributed throughout Heschl's gyrus, rather than being localized to a particular region, and this finding was evident regardless of the stimulus presented. These data provide a bridge across animal and human studies and aid our understanding of the processing of a critical percept associated with acoustic stimuli.

Audiometric Outcomes After the Middle Cranial Fossa Repair of Superior Semicircular Canal Dehiscence.

To evaluate the audiometric outcomes after the middle cranial fossa approach (MCF) for superior canal dehiscence (SCD) repair. Retrospective review. Tertiary referral center. SCD cases presented to a single institution between 2012 and 2022. The MCF repair of SCD. Air conduction (AC) threshold (250-8,000 Hz), bone conduction threshold (BC) (250-4,000 Hz), and air bone gap (ABG) (250-4,000 Hz) at each frequency, pure tone average (PTA) (500, 1,000, 2,000, 3,000 Hz). Among 202 repairs, 57% were bilateral SCD disease and 9% had previous surgery on the affected ear. The approach significantly narrowed ABG at 250, 500, and 1,000 Hz. The narrowing of ABG was achieved by both decreased AC and increased BC at 250 Hz, but mediated primarily by increased BC at 500 Hz and 1,000 Hz. Among cases without previous ear surgery, mean PTA remained in the normal hearing range (mean: preop, 21 dB; postop, 24 dB) and clinically important hearing loss (PTA increased by ≥10 dB) after the approach was noted in 15% of cases. Among cases with previous ear surgery, mean PTA remained in the mild hearing loss range (mean: preop, 33 dB; postop, 35 dB) and clinically important hearing loss after the approach was noted in 5% of cases. This is the largest study to date examining the audiometric outcomes after the middle cranial fossa approach for SCD repair. Findings of this investigation support that the approach is effective and safe with long-term hearing preservation for most.

Sound detection and production mechanisms in aquatic decapod and stomatopod crustaceans.

The sensory systems of crustaceans (aquatic decapods and stomatopods) have adapted to a diverse range of aquatic ecosystems. Sound production in aquatic crustaceans is more widespread than previously thought, and has been shown to play a major role in many of their life-history strategies; however, there are still many gaps in our understanding of their sound reception abilities. Crustaceans have three main sensory receptors for sound - the statocyst, superficial hair cells and chordotonal organs - which are all sensitive to the particle motion component of the sound field, rather than the pressure component. Our current understanding of these receptors is that they are sensitive to low-frequency sounds (<2000 Hz). There are a wide variety of sound-producing mechanisms employed by these animals, ranging from stridulation to implosive cavitation (see Glossary). These signals are used for a range of social behaviours, such as courtship, territorial defence and assessing 'resource guarding'. Furthermore, there are examples of sound signals that exceed their hearing range, highlighting a mismatch in our understanding of their hearing systems. This mismatch provides weight to the suggestion that another sound transmission channel - substrate-borne vibrations - might be at play, particularly because most crustaceans live on or near the seafloor. Finally, suggestions are made regarding potential future work that is needed to fill the substantial gaps in our understanding of how crustaceans hear and produce sound.

Electron trajectories in a collisional crossed-field gap

The Hull cutoff represents the maximum magnetic field in a vacuum crossed-field gap (CFG) such that an electron emitted from the cathode reaches the anode. Prior studies demonstrated that introducing ions into a CFG always causes increased excursion of electrons toward the anode. In this paper, we assess a collisional CFG by incorporating collision frequency into the electron force law. The theoretical electron trajectories agree well with a one-dimensional particle-in-cell simulation and demonstrate that emitted electrons always cross a collisional CFG. We derive a modified Hull cutoff condition for a collisional CFG corresponding to an electron reaching the anode with zero velocity in the direction of the electric field. Rather than representing the threshold for magnetic insulation, this condition gives the maximum magnetic field and maximum collision frequency for which an electron reaches the anode without turning around; higher magnetic fields and/or collision frequencies cause the electron to turn around before crossing the gap. Further increasing either quantity causes the electron to change direction more frequently as it crosses the gap, noticeably increasing the transit time with each change in electron direction. In the limit of high collision frequency, the electron velocity across the gap approaches a constant, meaning that electrons will reach the anode at nonzero velocity. The transit time above this condition increases smoothly and monotonically with increasing magnetic field or collision frequency. These results elucidate the implications of collisions on magnetic insulation for future assessments of the limiting current in a collisional CFG.

Matching the pitch perception of the cochlear implanted ear with the contralateral ear in patients with single-sided deafness: a novel approach.

Single-sided deaf patients following cochlear implantation often compare the sound quality of their implanted ear with normal hearing. The interaural differences can result in dissatisfaction with speech comprehension and reduced time of usage of the speech processor; hence, prolonging auditory adaptation time. The proposed calibration method presented in this study demonstrates how the frequency distribution of the cochlear implant can be set to adequately approximate the pitch perception of the contralateral normal hearing ear towards improving speech intelligibility in a noisy environment. In 12 postlingual single-sided deaf patients, subjective interaural pitch-matching was carried out to determine new central frequencies for the reallocation of the frequency bands of their speech processor (CP910, CP950 or CP1000, Cochlear, Australia). The patients were asked to compare the pitch of the tones presented to their normal hearing ear to the pitch of individual channels of their cochlear implant (CI522 or CI622, Cochlear, Australia). A third-degree polynomial curve was fit to the acquired matching frequencies to create the new frequency allocation table. Audiological measurements (free-field aided thresholds, speech reception thresholds, and monosyllabic word recognition score) in noise, together with a Speech, Spatial and Qualities of Hearing Scale (SSQ12) questionnaire (short version of the original SSQ) results were evaluated prior to the pitch-matching procedure, and again, 2 weeks later. The free-field aided thresholds of the patients showed no greater shift than ± 5dB following the procedure; however, their monosyllabic word recognition score in noise improved significantly (mean - 9.58%, SD 4.98%, matched pairs t test comparison: p < 0.001). The results of the SSQ12 questionnaire also showed significant improvement in speech intelligibility, sound localization, and sound quality (mean 0.96 points, SD 0.45 points, matched pairs t test comparison: p < 0.001). Matching the pitch perception of the implanted cochlea with the sensation of the normal hearing contralateral ear, resulted in significant changes in the quality of hearing in patients with single-sided deafness. It is plausible the procedure can usher positive results in bimodal patients or following sequential bilateral cochlear implantation.

0486 The Effect of Acoustic Resonance Therapy on CPAP Adherence

Abstract Introduction CPAP is the gold standard therapy for OSA. Unfortunately, a significant percentage of patients do not tolerate CPAP therapy. Of those who struggle, a significant portion state that nasal congestion is a limiting factor. Acoustic Resonance Therapy (ART) is a new non-medication based treatment for nasal congestion. We sought to determine if patients struggling with Medicare CPAP adherence and reporting nasal symptoms would benefit by the addition of ART. Methods This was an IRB approved, prospective, non-randomized, controlled pre-/post-treatment study. Twenty-five adult participants with an OSA diagnosis (AHI&amp;gt;5) were enrolled by BetterNight (OSA management, San Diego, CA). Participants were new to CPAP within the previous 90 days and were not Medicare adherent. Participants self-reported nasal congestion as a significant contributor to non-adherence. After struggling with CPAP for varying durations, participants began the Sonu vibrational headband system (SoundHealth Systems, Los Altos, CA) for 15 minutes each evening, immediately prior to wearing CPAP, on 28 sequential nights. The Sonu headband is worn circumferentially just above the eyebrows. It utilizes a smartphone application and the self-facing camera to capture a facial scan and estimate sinonasal volume which determines the appropriate resonant frequencies and harmonics. Two vibrational transducers produce a signal in the audible acoustic range, from 80 Hz to 16 KHz. Total nasal symptom scores (TNSS) were obtained at baseline and self-reported daily during Sonu use. Results Participants were 64% male, age 48.2±12.9, AHI 31.6±22.7, BMI 32.5±6.6 (mean±SD). On days the 25 participants used CPAP, mean hours (h) of use increased during the intervention from 2.7h±1.9 to 4.0h±2.2 (48%,p=0.004). On a subset of 12 participants for whom 28 days of pre/post data was available, mean total hours of CPAP use increased from 64.8h±51.6 to 94.0h±59.4 (45%,p=0.0107). CPAP Medicare adherence increased from 30.0%±27.4 to 45.8%±35.0 (53%,p=0.0175). TNSS decreased from 4.8±2.2 to 2.1±1.9 (-56%,p=0.0016). Conclusion The use of the Sonu headband was associated with increased hours of CPAP use, improved CPAP adherence and reduced nasal symptoms. Support (if any)

Bioinspired Soft Elastic Metamaterials for Reconstruction of Natural Hearing.

Natural hearing which means hearing naturally like normal people is critical for patients with hearing loss to participate in life. Cochlear implants have enabled numerous severe hearing loss patients to hear voice functionally, while cochlear implant users can hardly distinguish different tones or appreciate music subject to the absence of rate coding and insufficient frequency channels. Here a bioinspired soft elastic metamaterial that reproduces the shape and key functions of the human cochlea is reported. Inspired by human cochlea, the metamaterials are designed to possess graded microstructures with high effective refractive index distributed on a spiral shape to implement position-related frequency demultiplexing, passive sound enhancements of 10 times, and high-speed parallel processing of 168-channel sound/piezoelectric signals. Besides, it is demonstrated that natural hearing artificial cochlea has fine frequency resolution up to 30Hz, a wide audible range from 150-12000Hz, and a considerable output voltage that can activate the auditory pathway in mice. This work blazes a promising trail for reconstruction of natural hearing in patients with severe hearing loss.

Language experience predicts music processing in a half-million speakers of fifty-four languages

Tonal languages differ from other languages in their use of pitch (tones) to distinguish words. Lifelong experience speaking and hearing tonal languages has been argued to shape auditory processing in ways that generalize beyond the perception of linguistic pitch to the perception of pitch in other domains like music. We conducted a meta-analysis of prior studies testing this idea, finding moderate evidence supporting it. But prior studies were limited by mostly small sample sizes representing a small number of languages and countries, making it challenging to disentangle the effects of linguistic experience from variability in music training, cultural differences, and other potential confounds. To address these issues, we used web-based citizen science to assess music perception skill on a global scale in 34,034 native speakers of 19 tonal languages (e.g., Mandarin, Yoruba). We compared their performance to 459,066 native speakers of other languages, including 6 pitch-accented (e.g., Japanese) and 29 non-tonal languages (e.g., Hungarian). Whether or not participants had taken music lessons, native speakers of all 19 tonal languages had an improved ability to discriminate musical melodies on average, relative to speakers of non-tonal languages. But this improvement came with a trade-off: tonal language speakers were also worse at processing the musical beat. The results, which held across native speakers of many diverse languages and were robust to geographic and demographic variation, demonstrate that linguistic experience shapes music perception, with implications for relations between music, language, and culture in the human mind.

Behavioral response of Spodoptera exigua under bat echolocation call stress

Predation risk can shape prey behavior and limit population density. The ultrasonic sound emitted by bats creates a soundscape of fear which can affect moth trait expression and population dynamics via non-consumptive effects. Bat echolocation calls can be categorized as constant frequency (CF), frequency modulation (FM), or some combination of both (FM-CF-FM or FM-CF). Different sound characteristics may encode different levels of predation risk for moths and thus result in variable non-consumptive effects. To investigate the non-consumptive effects on moths of different types of bats echolocation calls, we played back three types of calls with distinct characteristics to an agricultural pest species, the beet armyworm, Spodoptera exigua, two CF calls from bats that prey on the moth, and one FM call from a bat that is sympatric with the moth and represents the echolocation sound typical of most insect-eating bats. Our results showed that the FM echolocation calls of the Oriental serotine bat, Eptesicus pachyomus, negatively affected the reproductive behavior of adult S. exigua, and altered larval energy metabolism and consumption. Calls of the big-eared horseshoe bat, Rhinolophus macrotis, with a dominant frequency of 58 kHz, only affected the reproductive behavior of adult S. exigua, whereas calls of the least horseshoe bat, Rhinolophus pusillus, with a dominant frequency of 110 kHz, had no measurable effects on S. exigua. The non-consumptive effects observed included reduced activity frequency, reduced food intake, and increased body weight of the moth in response to the soundscape of fear created by bats. Overall, FM calls with frequency within the moth's hearing range had greater effects on the moths. Our findings indicate that bat calls detectable by moths, whether or not the bats actually hunt them, create a soundscape of fear with negative impacts on moth behavior and life history, and likely make a valuable contribution to pest control.

Absorption, scattering and shadow by a noncommutative black hole with global monopole

In this paper, we investigate the process of massless scalar wave scattering due to a noncommutative black hole with a global monopole through the partial wave method. We computed the cross section of differential scattering and absorption at the low frequency limit. We also calculated, at the high frequency limit, the absorption and the shadow radius by the null geodesic method. We showed that noncommutativity causes a reduction in the differential scattering/absorption cross section and shadow radius, while the presence of the global monopole has the effect of increasing the value of such quantities. In the limit of the null mass parameter, we verify that the cross section of differential scattering, absorption and shadow ray approach to a non-zero value proportional to a minimum mass.