Sound Stimuli Research Articles

Brain response to sound motion-onset in human

This review comprehensively examines the features of the motion-specific brain response produced by human hearing system, the so-called motion-onset response (MOR). We discuss the interpretations of this component of auditory evoked potentials, its dependence on velocity and direction of sound motion and on various spatial characteristics of sound stimuli. We review the studies of event-related oscillations underlying the MOR which have shown that gradual sound motion causes the phase alignment of the delta-alpha range to the motion onset. We also consider the influence of audio-visual integration on motion processing. The MOR component as a correlate of the processes of spatial integration can provide new information about an early pre-conscious activation of brain structures that facilitates orientation and adaptation of a person to a changing acoustic environment.

Sensory and affective dimensions in loudness perception: Insights from young adults

Traditional psychoacoustic measures often lack accuracy in diagnosing hyperacusis and other sound tolerance disorders, possibly due to their reliance on artificial stimuli and unidimensional scales. The aim of this study was to assess loudness across sensory and affective dimensions using natural sounds, drawing on pain research wherein intensity and unpleasantness are assessed separately. We hypothesized that similar distinctions apply to loudness perception. A total of 102 young adults with normal to mild hearing loss rated 32 sound stimuli (pleasant, unpleasant, neutral, and artificial) at 10 intensities (40 to 100 dBA) on sensory and affective scales. They also completed the Hyperacusis Questionnaire, the Noise Sensitivity Scale, and the Hospital Anxiety and Depression Scale. Mixed linear models indicated both correlations and dissociations between scales that varied according to intensity and valence. Louder stimuli were rated as more unpleasant, but only at high intensities. On the sensory scale, sounds were perceived as louder with increasing intensity; however, at low to moderate intensities, pleasant and neutral sounds were rated as louder, whereas at higher intensities, artificial and unpleasant stimuli were rated as louder. On the affective scale, the perception of unpleasantness also increased with intensity, but less steeply. At high intensities, artificial stimuli were rated similarly to unpleasant stimuli. Noise sensitivity scores predicted louder and more unpleasant ratings, whereas depression scores were associated with softer and less pleasant perceptions. This study highlights the need for multidimensional approaches in audiology and suggests that the integration of sensory and affective scales with natural stimuli may improve the diagnosis and treatment of sound tolerance disorders.

An acoustic nanogenerator based on porous PDMS/ZnO/PVDF-TrFE structure for self-powered intermediated-frequency sound monitoring

Abstract Sound energy is widely present in natural environment, nowadays predominantly collected using voluminous and heavy rigid devices, limiting their portability. Till now, there are few reports about using flexible materials to collect sound energy, and it is usually susceptible to environmental humidity. This study combines flexible polymer polydimethylsiloxane (PDMS), piezoelectric material polyvinylidene difluoride trifluoroethylene (PVDF-TrFE), nano zinc oxide (ZnO), and conductive carbon nanotubes (CNTs) to fabricate a porous nano ZnO/PVDF-TrFE/CNTs PDMS sound-driven nanogenerator (PZPCP SNG). It amalgamates frictional and piezoelectric effects: its porous structure enables efficient collection of vibration and frictional energy generated by sound waves; the piezoelectric effect of PVDF-TrFE and nano ZnO facilitates the conversion of acoustic mechanical energy, collectively enhancing the generator's output. Experimental optimization yields the best production conditions, achieving optimal outputs of 481.1 mV (open-circuit voltage), 209.13 nA (short-circuit current) under 400 Hz/125 dB sound stimuli, with a surface power density of 9.1 µW/m² (volumetric power density of 2.28 mW/m³). And it can convert sound ranging from 63-3000 Hz. With hardware circuitry, up to 5 series-connected light-emitting diodes (LEDs) can be illuminated within the circuit, demonstrating a certain degree of sound recognition capability. The proposed PZPCP SNG design is simple, effective, and lightweight, enabling flexible and stable intermediated-frequency acoustic energy harvesting. Its hydrophobic structural characteristics render it adaptable to various humidity, presenting a new approach toward widespread low-power sound detection and self-powering applications.

Study of Peculiarities of the Formation of Behavioral Skills in Rats in the Three-Arm Maze

The aim of our experimental research was to explore the formation of behavioral skills such as active avoidance learning in different species of rats in the three-arm maze. To determine which species is the most trainable, our study used 100 white outbred, 30 Long Evans and 30 Dumbo rats. The conditioned stimulus was a combination of playing the sound and turning off the light in a randomly selected target arm of the maze. 5 sec after the buzzer started to sound the light was turned off, then an unconditioned stimulus, the electric power, was applied to non-target arm, and the light was turned on. The task of the rat was to change the arm and enter the target (safety) arm of the maze after the sound stimulus. When the task was done, the floor of non-target arm was not charged furhter and the light was turned off. The interval between conditioned/unconditioned stimulus combinations was 30 s, it took 1 month to train each rat species and 20 sessions with different combinations of stimuli were used every day. The rat was considered trained when the probability of achieving the goal within a time limit not exceeding 6 s is 70% or higher of cases. It has been found that Dumbo rats are the best animals to train quickly in large groups to respond to an irritating stimulus.

Exploring Sound Frequency Detection in the Golden Rabbitfish, Siganus guttatus: A Behavioral Study.

This study investigates the auditory capabilities of Golden Rabbitfish (Siganus guttatus) and the potential efficacy of sound-based deterrent methods for behavior control. Behavioral experiments were conducted on Golden Rabbitfish to assess their responses to sound stimuli. Sinusoidal pulses in the range of 100~800 Hz, based on previous research on auditory evoked potentials (AEPs), were utilized. An analysis of behavioral trajectories, swimming speed, and acceleration changes revealed the fish's reactions to varying frequency sound stimuli. The results indicate that Golden Rabbitfish exhibited increased swimming activity and speed when stimulated by sound and notably moved away from the source under prolonged exposure to low-frequency acoustic signals. Specifically, the fish displayed the most significant response to 200 Hz sinusoidal pulses with a response threshold of 113~126 dB. These findings suggest that Golden Rabbitfish are particularly sensitive to low-frequency noise, aligning with AEP study outcomes. This study concludes that employing sound stimuli to deter Golden Rabbitfish in practical settings holds promise for mitigating economic losses in seaweed farming due to Golden Rabbitfish grazing.

Research on the effects of railway noise and biaxial vibration on calculation disturbances

This study conducted an evaluation experiment on simultaneous exposure to noise and two-axis vibration stimuli from railways, using noise stimuli from railways and two-axis vibration stimuli in the horizontal-vertical direction, and verified differences in evaluation of interference due to differences in noise and the direction of vibration. The experiment was conducted in a laboratory with a vibration exciter placed in a simple anechoic chamber, with the participation of 20 students. The stimuli presented utilized vibrations recorded indoors and sounds recorded outdoors. Both vertical and horizontal vibrations were presented in four levels, and the sound stimuli were presented at three levels: 50, 60, and 70 dB. The evaluation of annoyance and interference showed that under conditions of noise levels of 50 dB and 60 dB, discomfort and interference increased as the vertical vibration level increased with horizontal vibration levels (X: 2-6), confirming the combined effect of vertical vibration and noise. Even under conditions of a noise level of 70 dB, except for vibration conditions X: 2, Z: 2, and X: 6, Z: 6, the combined effect of vertical vibration and noise was confirmed.

A loudness evaluation test of environmental noises with complex frequency characteristics: a comparison of A-weighted sound pressure level and Moore-Glasberg loudness level

Noises generated from HVAC systems and machinery have complex frequency characteristics that include various frequency components such as tonal components. In order to evaluate and cope with these environmental noises appropriately, it is necessary to apply a noise evaluation index that fits well with psychological responses. In this study, the authors focused on loudness, the most primary aspect of psychoacoustics, and conducted a evaluation experiment using actual recorded sounds. The results of the loudness evaluation were examined using two noise evaluation indexes: A-weighted sound pressure level and Moore-Glasberg loudness level dictated by ISO532-2. As a result, the Moore-Glasberg loudness level showed better agreement with the evaluated loudness regardless of the type of the sound stimuli.

Simulation of pulse width modulation strategies: validation based on sound quality evaluations

Though the noise emitted by an electrical machine is less loud than the one from a combustion engine, the existing literature shows it is not always more pleasant. This is because of its strong tonal content, due to deterministic excitations (e.g. electromagnetic slotting and switching effects, mechanical gear mesh effects). The main source of magnetic noise is the radiation of the stator submitted to electromagnetic forces, which are harmonic by nature. Their highest frequency components are generated by the Pulse Width Modulation (PWM) technique designed to vary the supply frequency and operating speed of the electric machine. Several PWM strategies exist, leading to specific harmonic spectra. A temporal simulation model has been developed to auralize the corresponding electromagnetic noise emitted by the machine, considering its mechanical and electrical parameters. A testbench has been adapted to test the relevance of the model, both from an electrical and acoustic point of view. The simulation model and the testbench can be used to generate virtual and real sound stimuli to be assessed in a jury testing. The subjective evaluations allow to assess the relevance of the auralization model, but also to identify the least annoying strategies.

Whistle or squeal? Distinguish and evaluate two typical abnormal sounds of collaborative robots

The whistle and squeal are two typical abnormal sounds among the radiated noise of running collaborative robots, indicating potential faults and causing discomfort through auditory perception. This study investigated whether psychoacoustic parameters for sound quality could distinguish the whistle and squeal and evaluate their discomfort. A total of 20 abnormal sound stimuli, including 6 whistles and 14 squeals, were obtained from various collaborative robots. The cepstrum characteristics and sound quality metrics (i.e., roughness, sharpness, fluctuation strength and tonality) of all stimuli were analyzed by controlling the equal loudness. Twenty-four participants rated the 'discomfort of abnormal sound in the stimuli' on an 11-point scale. The results show that the modulation frequencies of the fundamental frequency of the whistles were 2.9 Hz to 5.5 Hz, whereas the squeals had no obvious modulation characteristics. The modulation frequencies of the fundamental frequency were highly correlated (with a correlation coefficient of 0.89) to the discomfort responses for whistles, whereas tonality was significantly correlated (with a correlation coefficient of 0.82) to the discomfort responses for squeals. The linear models using single dependent variables of modulation frequency in cepstrum and tonality had determination coefficients of 0.77 and 0.66, respectively, in evaluating the discomfort of whistles and squeals.

An interpretable tinnitus prediction framework using gap-prepulse inhibition in auditory late response and electroencephalogram.

Tinnitus is a neuropathological condition that results in mild buzzing or ringing of the ears without an external sound source. Current tinnitus diagnostic methods often rely on subjective assessment and require intricate medical examinations. This study aimed to propose an interpretable tinnitus diagnostic framework using auditory late response (ALR) and electroencephalogram (EEG), inspired by the gap-prepulse inhibition (GPI) paradigm. We collected spontaneous EEG and ALR data from 44 patients with tinnitus and 47 hearing loss-matched controls using specialized hardware to capture responses to sound stimuli with embedded gaps. In this cohort study of tinnitus and control groups, we examined EEG spectral and ALR features of N-P complexes, comparing the responses to gap durations of 50 and 20 ms alongside no-gap conditions. To this end, we developed an interpretable tinnitus diagnostic model using ALR and EEG metrics, boosting machine learning architecture, and explainable feature attribution approaches. Our proposed model achieved 90 % accuracy in identifying tinnitus, with an area under the performance curve of 0.89. The explainable artificial intelligence approaches have revealed gap-embedded ALR features such as the GPI ratio of N1-P2 and EEG spectral ratio, which can serve as diagnostic metrics for tinnitus. Our method successfully provides personalized prediction explanations for tinnitus diagnosis using gap-embedded auditory and neurological features. Deficits in GPI alongside activity in the EEG alpha-beta ratio offer a promising screening tool for assessing tinnitus risk, aligning with current clinical insights from hearing research.

Using the Cocktail Party Effect to Add the Coding Dimension of Auditory Event Related Potential Brain-Computer Interface.

The auditory event-related potential based brain-computer interface (aERP-BCI) is a classical paradigm of brain-computer communication. To improve the coding efficiency of aERP-BCI, this study proposes a method using two parallel voice channels to add the coding dimension based on the cocktail party effect. The novel paradigm used male and female voices to establish two parallel oddball sound stimulus sequences. In comparison, the baseline paradigm only presented male or female stimulus sequences. Both the double voice condition (DVC) and the single voice condition (SVC) paradigms carried out offline experiments and the DVC also carried out online experiment. Subsequently, the EEG signal and BCI operation results were compared and analyzed. The cocktail party effect caused a significant difference in the EEG responses of non-target stimulus between the focused vocal channel and the ignored vocal channel under the DVC paradigm, and the focused and ignored channels achieved a recognition accuracy of 97.2%. The target recognition rate of DVC was 82.3%, with no significant difference compared with 85% of SVC while the information transfer rate (ITR) of DVC reaching 15.3 bits/min was significantly higher than that of SVC. The cocktail party effect improves the coding efficiency by adding parallel channels without reducing the target/non-target stimulus recognition in the focused vocal channel. This provides a novel direction for the performance improvement of aERP-BCI.

Complex dynamic behavioral transitions in auditory neurons induced by chaotic activity

Chaotic sequences are widely used in secure communication due to their high randomness. Chaotic resonance (CR) refers to the resonant response of a system to weak signals induced by chaotic activity, but its practical application remains limited. This study designs a simplified FitzHugh-Nagumo (FHN) auditory neuron model by simulating the physiological activities of auditory neurons and considering the combined stimulation of chaotic activity and sound signals. It is found that the neuron dynamics depend on both external sound stimuli and chaotic current intensity. Chaotic currents induce spikes in the neuron output sequence through CR, and the spikes become more frequent with increasing current intensity, eventually leading to a chaotic state regardless of the initial state. However, the sensitivity of the initial value of this chaotic sequence shifts to the chaotic current excitation system. The injection of chaotic currents can reduce the system's average Hamiltonian energy under certain conditions. By measuring the complexity of the generated sequences, we find that the addition of chaotic currents can enhance the complexity of the original sequences, and the enhancement ability increases with the intensity. This provides a new approach to enhance the complexity of original chaotic sequences. Moreover, different chaotic currents can induce different chaotic sequences with varying abilities to enhance the complexity of the original sequences. We hope our work can contribute to secure communication.

Sound in mode on: how sound stimuli influence customer engagement?

AbstractThe objectives of this research are as follows: (i) to study whether the presence of sound stimuli influences customer engagement; (ii) to assess this effect on different dimensions of customer engagement (sensory experience, approach-avoidance response, and emotional response); and (iii) to study whether product type and customer involvement moderate the effect of sound on customer engagement. This research analyzes the effect of two different sound stimuli for two different product types on two digital channels. The experimental design for Study 1 is a 2 sound (sound associated with the product vs. no sound) × 2 product type (hedonic vs. utilitarian) displayed in a social network (Instagram) environment. The experimental design for Study 2 is a 2 sound (voiceover vs. no sound) × 2 product type (hedonic vs. utilitarian) displayed in a blog. Both studies additionally incorporate measured variables, with a particular focus on customer involvement (low and high). A total of 512 participants interacted with a condition and then completed a questionnaire. The presence of sound increases customer engagement in the sensory experience and approaching response. The interaction of sound (voice-over) and the hedonic product positively influences the emotional response, and customer involvement negatively moderates the influence of sound on the sensory experience.

Intranasal vs. intramuscular administration of azaperone, midazolam and ketamine in pigs.

To compare the efficacy of intranasal (IN) and intramuscular (IM) administrations of azaperone (3 mg kg-1), midazolam (0. 3 mg kg-1), and ketamine (7 mg kg-1) combination (AMK) in pigs. Study design: Randomized clinical trial. Animals: sixteen adult male pigs, immunocastrated, of mixed lineage. In phase I, these animals were randomly assigned to intranasal (GIN, n = 8) and intramuscular (GIM, n = 8) groups for arterial blood sample collection at 10, 20, 30, 45, 60, and 90 min after AMK administrations for gas and electrolyte analysis. In phase II, performed 1 week after phase I, the 16 pigs were allocated to both groups (GIM, n = 16/GIN, n = 16) and submitted to the same chemical restraint (CR) protocol, with a 96-h interval between administrations. Behavioral parameters (degree of CR, muscle relaxation, loss of postural reflex, and sound stimulus response) and vital parameters (pulse rate, respiratory rate, oxygen saturation, and rectal temperature) were evaluated after recumbency (Trec) and at 5, 15, 30, 45, 60, and 90 min after administrations. In addition, the latency period and duration of CR were determined. Latency to recumbency and duration of CR in GIN were shorter. CR scores did not vary between groups. Muscle relaxation was more intense in GIN at Trec. An initial tachycardia was observed, followed by a reduction in heart rate from T5 to T90 in both treatments (p < 0.05). The respiratory rate was higher at T45, T60, and T90 in GIN compared to baseline. Rectal temperature reduced in GIM from T45 onwards. elevated at T90 in the GIM (p < 0.05) and there was an incidence of mild hypoxemia in 47% of the animals in the GIM. IN administration was as effective as IM administration in promoting safe chemical restraint, with minimal changes in homeostasis, with a shorter duration and latency period.

Effects of Phasic Activation of Locus Ceruleus on Cortical Neural Activity and Auditory Discrimination Behavior.

Although the locus ceruleus (LC) is recognized as a crucial modulator for attention and perception by releasing norepinephrine into various cortical regions, the impact of LC-noradrenergic (LC-NE) modulation on auditory discrimination behavior remains elusive. In this study, we firstly recorded local field potential and single-unit activity in multiple cortical regions associated with auditory-motor processing, including the auditory cortex, posterior parietal cortex, secondary motor cortex, anterior cingulate cortex, prefrontal cortex, and orbitofrontal cortex (OFC), in response to optogenetic activation (40 Hz and 0.5 s) of the LC-NE neurons in awake mice (male). We found that phasic LC stimulation induced a persistent high gamma oscillation (50-80 Hz) in the OFC. Phasic activation of LC-NE neurons also resulted in a corresponding increase in norepinephrine levels in the OFC, accompanied by a pupillary dilation response. Furthermore, when mice were performing a go/no-go auditory discrimination task, we optogeneticaly activated the neural projections from LC to OFC and revealed a shortened latency in behavioral responses to sound stimuli and an increased false alarm rate. These impulsive behavioral responses may be associated with the gamma neural activity in the OFC. These findings have broadened our understanding of the neural mechanisms involved in the role of LC in auditory-motor processing.

Toward an endophenotype for ADHD: Exploring the duration mismatch negativity in drug-free children with ADHD

Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent disorders in children that is considered to affect early stages of information processes. Inefficient processing of temporal information, which is a vital auditory processing skill suggests itself as a potential candidate for investigating ADHD deficits. The Research Domain Criteria (RDoC), a neuroscience-based research framework, has been introduced to study mental illness without relying on pre-established diagnostic categories. In this regard, Mismatch Negativity (MMN) has been considered an ideal electrophysiological marker for investigating ADHD deficits. This study investigates alterations in the amplitude and latency of the MMN component in response to changes in the duration and Inter-Stimulus Interval (ISI) of basic sound stimuli within an oddball task. The MMN paradigm was employed to examine duration deviations in ADHD (n = 25, 84% male, mean age: 7.3 years, SD = 2.01) compared to Control group of typically developing (TD) children (n = 25, 72% male, mean age: 7.2 years, SD = 1.92). Participants with ADHD were introduced from an accredited psychiatrist. TD children were recruited from social media and online forms. Both groups were matched in terms of gender, age and IQ. The psychological tests conducted in this study included Conners’ Parent Rating Scale (CPRS), Gilliam Autism Rating Scale|Third Edition (Gars3), Sensory profile questionnaire and Edinburgh Handedness inventory. Our findings revealed reduced MMN amplitudes in response to two blocks of duration and ISI-based deviations in ADHD children. To elaborate in greater detail, at Fz, in Duration and ISI block, respectively, the ADHD group showed an amplitude of −1.2097 ± 0.2938 and −0.8553 ± 0.4423, while the normal group showed an amplitude of −1.8325 ± 0.3689 and −2.0855 ± 0.3802. Additionally, at Cz, the ADHD group exhibited a shorter amplitude (-1.2515 ± 0.3261 and −0.9367 ± 0.3432) compared to the normal group (−2.1319 ± 0.4445 and −2.7561 ± 0.4883), in the duration and ISI blocks, respectively. Furthermore, children with ADHD display longer MMN latencies in both experimental blocks, suggesting atypical responses. To provide more detail, at Fz, the ADHD group displayed MMN latencies of 239.68 ± 5.059 and 226.88 ± 4.885 in the Duration and ISI blocks, respectively, whereas the normal group showed MMN latencies of 228.56 ± 6.584 and 213.56 ± 4.153. Similarly, at Cz, the ADHD group exhibited longer MMN latencies (234.40 ± 5.741 and 231.44 ± 5.464) compared to the normal group (227.52 ± 6.710 and 218.00 ± 5.261) in the Duration and ISI blocks, respectively. Our findings were interpreted in the context of the internal clock model, which involves the pace of an internal pacemaker regulated by dopamine (DA) levels. The convergence of MMN and auditory timing abnormalities within the RDoC framework suggests their potential as endophenotypes for ADHD, highlighting the significance of sensory processing in understanding the disorder.

Increased risky choice during forced abstinence from fentanyl on the cued rat gambling task.

The use of illicit opioids has arguably never been more risky; street drug potency can be dangerously high, is often unknown to the consumer, and results in multiple daily fatalities worldwide. Furthermore, substance use disorder (SUD) is associated with increased maladaptive, risky decisions in laboratory-based gambling tasks. Animal studies can help determine whether this decision-making deficit is a cause or consequence of drug use. However, most experiments have only assessed psychostimulant drugs. To assess differences in decision-making strategies both before, during, and after self-administration of fentanyl in male and female Long Evans rats. Male and female Long Evans rats were trained to perform the rat gambling task (rGT), loosely based on the Iowa Gambling Task (IGT) used clinically, and/or self-administer fentanyl. We used the cued version of the rGT, in which sound and light stimuli signal sugar pellet rewards, as cocaine self-administration has the greatest effects on decision making in this task variant. After training on the cued rGT, female rats self-administered fentanyl more readily, an effect that was most apparent in optimal decision-makers. Contrary to previous reports using cocaine self-administration, decision-making was unaffected during fentanyl self-administration training in either sex. However, risky decision-making increased throughout forced abstinence from fentanyl in males. These findings complement those from human subjects, in whom preference for uncertain outcomes increased before relapse. These data highlight an abstinence-induced change in cognition that is unique to opiates as compared to psychostimulants, and which may critically contribute to the maintenance of addiction and relapse.

Multivariate disturbance filtering in auditory fNIRS signals using maximum likelihood gradient estimation method: Feasibility study using sound quality indices

Functional near-infrared spectroscopy (fNIRS) technology has been widely used to analyze biomechanics and diagnose brain activity. Despite being a promising tool for assessing the brain cortex status, this system is susceptible to disturbances and noise from electrical instrumentation and basal metabolism. In this study, an alternative filtering method, maximum likelihood generalized extended stochastic gradient (ML-GESG) estimation, is proposed to overcome the limitations of these disturbance factors. The proposed algorithm was designed to reduce multiple disturbances originating from heartbeats, breathing, shivering, and instrumental noises as multivariate parameters. To evaluate the effectiveness of the algorithm in filtering involuntary signals, a comparative analysis was conducted with a conventional filtering method, using hemodynamic responses to auditory stimuli and psycho-acoustic factors as quality indices. Using auditory sound stimuli consisting of 12 voice sources (six males and six females), the fNIRS test was configured with 18 channels and conducted on 10 volunteers. The psycho-acoustic factors of loudness and sharpness were used to evaluate physiological responses to the stimuli. Applying the proposed filtering method, the oxygenated hemoglobin concentration correlated better with the psychoacoustic analysis of each auditory stimulus than that of the conventional filtering method.

Comparisons of Audiologic Characteristics in Patients with Continuous and Intermittent Tinnitus.

No studies to date have compared audiologic characteristics in patients with continuous and intermittent tinnitus. The present study classified tinnitus patients into continuous and intermittent groups based on tinnitus duration and compared their audiologic characteristics. This study enrolled 604 patients with tinnitus from January 2019 to December 2022. Clinical manifestations, PTA results, the frequency and loudness of tinnitus, ABR, DPOAE, and TEOAE tests were compared in patients with continuous and intermittent tinnitus. Of the 604 patients, 231 (38.2%) had continuous and 373 (61.8%) had intermittent tinnitus. There were no significant between-group differences in otologic symptoms, tinnitus onomatopoeia. PTA showed that hearing thresholds, except at 125 Hz, were significantly higher in patients with continuous rather than intermittent tinnitus. The loudness of tinnitus was significantly greater in patients with continuous rather than intermittent tinnitus. ABR tests showed that the absolute latency of wave V was significantly longer in continuous than in intermittent tinnitus. Signal-to-noise ratios on TEOAE tests were significantly lower in patients with continuous rather than intermittent tinnitus at all frequencies tested (1, 1.5, 2, 3, and 4 kHz). Response rates to sound stimuli at all frequencies, except for 1 kHz, were significantly lower on DPOAE tests in patients with continuous rather than intermittent tinnitus. Continuous tinnitus is more common in males, more persistent over time, and is associated with a higher rate of hearing loss. In contrast, intermittent tinnitus is more common in women, appears acutely, and is associated with a relatively lower rate of hearing loss. Based on the findings of the current paper, it seems that audiologic characteristics may differ between patients with continuous and intermittent tinnitus.

Effect of age-related extended high frequency hearing loss on the subjective impressions of dental drill noise

Fear and anxiety among patients are sometimes evoked in dental clinics due to the sound of dental drills. This study aimed to explore the impact of age-related hearing loss in the extended high frequency (EHF) range above 8 kHz on individuals' subjective discomfort towards dental drill noise. After measuring pure-tone audiometric thresholds at both conventional and extended high frequencies, we used a psychoacoustic approach to evaluate subjective impressions of four dental drill sound stimuli, which featured varying frequency components, in 62 participants (aged 12–67 years). We found a significant decrease in hearing sensitivity within the EHF range as age increased, with notable differences in hearing thresholds at 14 kHz between teenage and older adults exceeding 65 dB. Furthermore, significant differences were observed between younger and older (above 40 years) participants in the subjective impressions of dental drill noise, emphasizing age as a critical factor in the perception of high frequency components. Consequently, age may influence the unpleasantness of dental drilling noise. Compared to older individuals, young participants may exhibit increased fear of dental procedures owing to physiological factors. These results underscore the need for age-appropriate noise control strategies in dental clinics to mitigate anxiety and improve patient comfort.