Amidst the clamor: Effects of emergency department noise on Physicians' health and attention

OBJECTIVE

This study aims to assess effects of noise on physicians' stress levels and attention capacities within an emergency department.

METHODS

In this prospective cross-sectional study, 15 physicians from a state hospital emergency department with 300,000 annual visits provided demographics, work factors, and physiologic data. Attention was evaluated through smartphone-based Stroop tests, while noise and heart rates were monitored via smartwatches.

RESULTS

Median physician age was 26, with 16 months' emergency department experience. Average sound intensity was 68.80 dB. Despite noise, physicians in green/yellow areas showed increased Stroop scores (p = 0.002). Heart rate responses correlated with noise changes. End-of-shift surveys highlighted physicians' adaptability and resilience to high noise levels.

CONCLUSION

Noisy emergency departments pose health risks to physicians, but noise-related stress did not significantly affect attention, beneficial for patient care.

Why and When to Treat Snoring

It is estimated that half of the adult population older than 60 years snores. This article discusses the many aspects of snoring, including impacts on bed partners, the individual who snores, and when and how to appropriately evaluate, diagnose, and treat the perpetrator. The goal is for clinicians to expand their knowledge regarding diagnosis and treatment of the phenomenon of snoring.It is estimated that half of the adult population over the age of 60 years of age snores. This chapter discusses snoring, including the impact on bed partners, the individual that snores and when and how to treat the snorer. The goal is for clinicians to expand their knowledge regarding diagnosis and treatment of patients who snores.

Mismatch negativity and psychophysical detection of rising and falling intensity sounds

Human subjects demonstrate a perceptual priority for rising level sounds compared with falling level sounds. The aim of the present study was to investigate whether or not the perceptual preference for rising intensity can be found in the preattentive processing indexed by mismatch negativity (MMN). Reversed oddball stimulation was used to produce MMNs and to test the behavioral discrimination of rising, falling and constant level sounds. Three types of stimuli served as standards or deviants in different blocks: constant level sounds and two kinds of rising/falling sounds with gradual or stepwise change of intensity. The MMN amplitudes were calculated by subtracting ERPs to identical stimuli presented as standard in one block and deviant in another block. Both rising and falling level deviants elicited MMNs which peaked after 250 ms and did not overlap with N1 waves. MMN was elicited by level changes even when the deviants were not discriminated behaviorally. Most importantly, we found dissociation between earlier and later stages of auditory processing: the MMN responses to the level changes were mostly affected by the direction of deviance (increment or decrement) in the sequence, whereas behavioral performance depended on the direction of the level change within the stimuli (rising or falling).

Left and right reaction time differences to the sound intensity in normal and AD/HD children

OBJECTIVES

Right hemisphere, which is attributed to the sound intensity discrimination, has abnormality in people with attention deficit/hyperactivity disorder (AD/HD). However, it is not studied whether the defect in the right hemisphere has influenced on the intensity sensation of AD/HD subjects or not. In this study, the sensitivity of normal and AD/HD children to the sound intensity was investigated.

METHODS

Nineteen normal and fourteen AD/HD children participated in the study and performed a simple auditory reaction time task. Using the regression analysis, the sensitivity of right and left ears to various sound intensity levels was examined.

RESULTS

The statistical results showed that the sensitivity of AD/HD subjects to the intensity was lower than the normal group (p < 0.0001). Left and right pathways of the auditory system had the same pattern of response in AD/HD subjects (p > 0.05). However, in control group the left pathway was more sensitive to the sound intensity level than the right one (p = 0.0156).

CONCLUSIONS

It can be probable that the deficit of the right hemisphere has influenced on the auditory sensitivity of AD/HD children. The possible existent deficits of other auditory system components such as middle ear, inner ear, or involved brain stem nucleuses may also lead to the observed results. The development of new biomarkers based on the sensitivity of the brain hemispheres to the sound intensity has been suggested to estimate the risk of AD/HD. Designing new technique to correct the auditory feedback has been also proposed in behavioral treatment sessions.

Brain responses to sound intensity changes dissociate depressed participants and healthy controls

Depression is associated with bias in emotional information processing, but less is known about the processing of neutral sensory stimuli. Of particular interest is processing of sound intensity which is suggested to indicate central serotonergic function. We tested weather event-related brain potentials (ERPs) to occasional changes in sound intensity can dissociate first-episode depressed, recurrent depressed and healthy control participants. The first-episode depressed showed larger N1 amplitude to deviant sounds compared to recurrent depression group and control participants. In addition, both depression groups, but not the control group, showed larger N1 amplitude to deviant than standard sounds. Whether these manifestations of sensory over-excitability in depression are directly related to the serotonergic neurotransmission requires further research. The method based on ERPs to sound intensity change is fast and low-cost way to objectively measure brain activation and holds promise as a future diagnostic tool.

Sound level intensity severely disrupts sleep in ventilated ICU patients throughout a 24-h period: a preliminary 24-h study of sleep stages and associated sound levels

Background

It is well recognized that sleep is severely disturbed in patients in intensive care units (ICU) and that this can compromise their rehabilitation potential. However, it is still difficult to objectively assess sleep quantity and quality and the determinants of sleep disturbance remain unclear. The aim of this study was therefore to evaluate carefully the impact of ICU sound intensity levels and their sources on ICU patients’ sleep over a 24-h period.

Methods

Sleep and sound levels were recorded in 11 ICU intubated patients who met the criteria. Sleep was recorded using a miniaturized multi-channel ambulatory recording device. Sound intensity levels and their sources were recorded with the Nox-T3 monitor. A 30-s epoch-by-epoch analysis of sleep stages and sound data was carried out. Multinomial and binomial logistic regressions were used to associate sleep stages, wakefulness and sleep–wake transitions with sound levels and their sources.

Results

The subjects slept a median of 502.2 [283.2–718.9] min per 24 h; 356.9 [188.6–590.9] min at night (22.00–08.00) and 168.5 [142.5–243.3] during daytime (8 am–10 pm). Median sound intensity level reached 70.2 [65.1–80.3] dBC at night. Sound thresholds leading to disturbed sleep were 63 dBC during the day and 59 dBC during the night. With levels above 77 dBC, the incidence of arousals (OR 3.9, 95% CI 3.0–5.0) and sleep-to-wake transitions (OR 7.6, 95% CI 4.1–14) increased. The most disturbing noises sources were monitor alarms (OR 4.5, 95% CI 3.5–5.6) and ventilator alarms (OR 4.2, 95% CI 2.9–6.1).

Conclusions

We have shown, in a small group of 11 non-severe ICU patients, that sound level intensity, a major disturbance factor of sleep continuity, should be strictly controlled on a 24-h profile.

Presenting changes in acoustic features synchronously to respiration alters the affective evaluation of sound

Synchronization of respiration to cyclic auditory stimuli is a well-observed phenomenon and known to have an effect on affective evaluation of the presented sound. However, no studies have separated the effect of the change in respiratory movement itself and that when there is synchrony between respiration and sound. In this study, we used a system that can change the acoustic features synchronously with the respiration phase and directly investigated the effect the synchrony has on affective ratings without changing respiratory movements. An acoustic stimulation was presented where the sound intensity (SI) or fundamental frequency (F0) was modulated in response to the participant's respiration phase. Affective evaluations of the acoustic stimuli were made by using the Self-Assessment Manikin (SAM). The experiments compared synchronous and asynchronous conditions. In the synchronous condition, SI (or F0) was increased with inhalation (decreased with exhalation) or decreased with inhalation (increased with exhalation). In the asynchronous condition, a sound identical to that presented in the synchronous condition was replayed. The participants evaluated sounds that were acoustically the same but where the temporal relationship differed between respiration and the acoustic features. In our results, significantly higher arousal ratings were observed when the change in SI and respiration (inhalation or exhalation) was synchronous and when the increase in F0 and inhalation was synchronous. This suggests that the synchronous phenomenon between respiration and auditory stimuli can play a critical role in affective evaluation.

The representation of level and loudness in the central auditory system for unilateral stimulation

Loudness is the perceptual correlate of the physical intensity of a sound. However, loudness judgments depend on a variety of other variables and can vary considerably between individual listeners. While functional magnetic resonance imaging (fMRI) has been extensively used to characterize the neural representation of physical sound intensity in the human auditory system, only few studies have also investigated brain activity in relation to individual loudness. The physiological correlate of loudness perception is not yet fully understood. The present study systematically explored the interrelation of sound pressure level, ear of entry, individual loudness judgments, and fMRI activation along different stages of the central auditory system and across hemispheres for a group of normal hearing listeners. 4-kHz-bandpass filtered noise stimuli were presented monaurally to each ear at levels from 37 to 97dB SPL. One diotic condition and a silence condition were included as control conditions. The participants completed a categorical loudness scaling procedure with similar stimuli before auditory fMRI was performed. The relationship between brain activity, as inferred from blood oxygenation level dependent (BOLD) contrasts, and both sound level and loudness estimates were analyzed by means of functional activation maps and linear mixed effects models for various anatomically defined regions of interest in the ascending auditory pathway and in the cortex. Our findings are overall in line with the notion that fMRI activation in several regions within auditory cortex as well as in certain stages of the ascending auditory pathway might be more a direct linear reflection of perceived loudness rather than of sound pressure level. The results indicate distinct functional differences between midbrain and cortical areas as well as between specific regions within auditory cortex, suggesting a systematic hierarchy in terms of lateralization and the representation of level and loudness.¹.

The illusion of nonmediation in telecommunication: voice intensity biases distance judgments to a communication partner

The illusion of nonmediation is an experience in mediated communication where individuals respond as if the medium is not there. It is frequently associated with advanced media technology, such as virtual environments and teleconference systems. In this paper, we investigate whether people experience an illusion of nonmediation during interactions as simple as making a phone call. In three experiments, participants were asked to listen to someone's voice on a mobile phone (Experiment 1) or through VoIP software (Experiment 2 and 3) before guessing the location of the person and indicating this location on a map. Results consistently demonstrated that louder voices were judged to be closer, as if the technical mediation was ignored. Combining the three experiments, a small-scale meta-analysis yielded an effect size estimate of d=0.37 for the 'louder-as-closer' effect. Implications of the results and suggestions for future research are discussed.

The effect of sound intensity on velopharyngeal function in normal individuals

OBJECTIVE

Velopharyngeal closure is an important physiological process contributing to the normal function of speech and swallowing. The aim of this study was to analyze the influence of sound intensity on velopharyngeal function in normal individuals.

MATERIALS AND METHODS

Lateral cephalograms of 38 volunteers obtained at rest and during phonation of vowel /i:/ at both high and low sound intensity were carefully analyzed. The digital sound level meter was used to evaluate and record the sound intensity of the phonation process. The angular and linear parameters on the lateral cephalograms were then measured to reveal the correlation between sound intensity and velopharyngeal closure.

RESULTS

All the angular parameter values measured in the study were significantly greater in high sound intensity condition. As for linear parameters, all values were found to be significantly larger at high sound intensity, except for the effective velopharyngeal length and the vertical velopharyngeal length. A multiple linear regression model was set up to describe the correlation between the sound intensity, the effective velopharyngeal length, and velopharyngeal closure. With the increase of sound intensity and the decrease of the effective velopharyngeal length, the width of velopharyngeal closure is enlarged.

CONCLUSIONS

As one of the characteristic features of sound wave, the sound intensity was found to affect the objectively measured parameters of velopharyngeal closure on lateral cephalograms.

Music, perceived arousal, and intensity: psychophysiological reactions to Chopin's "Tristesse"

The present study investigates the relation of perceived arousal (continuous self-rating), autonomic nervous system activity (heart rate, heart rate variability) and musical characteristics (sound intensity, musical rhythm) upon listening to a complex musical piece. Twenty amateur musicians listened to two performances of Chopin's "Tristesse" with different rhythmic shapes. Besides conventional statistical methods for analyzing psychophysiological reactions (heart rate, respiration rate) and musical variables, semblance analysis was used. Perceived arousal correlated strongly with sound intensity; heart rate showed only a partial response to changes in sound intensity. Larger changes in heart rate were caused by the version with more rhythmic tension. The low-/high-frequency ratio of heart rate variability increased--whereas the high frequency component decreased--during music listening. We conclude that autonomic nervous system activity can be modulated not only by sound intensity but also by the interpreter's use of rhythmic tension. Semblance analysis enables us to track the subtle correlations between musical and physiological variables.

Intratympanic manganese administration revealed sound intensity and frequency dependent functional activity in rat auditory pathway

The cochlear plays a vital role in the sense and sensitivity of hearing; however, there is currently a lack of knowledge regarding the relationships between mechanical transduction of sound at different intensities and frequencies in the cochlear and the neurochemical processes that lead to neuronal responses in the central auditory system. In the current study, we introduced manganese-enhanced MRI (MEMRI), a convenient in vivo imaging method, for investigation of how sound, at different intensities and frequencies, is propagated from the cochlear to the central auditory system. Using MEMRI with intratympanic administration, we demonstrated differential manganese signal enhancements according to sound intensity and frequencies in the ascending auditory pathway of the rat after administration of intratympanic MnCl2.Compared to signal enhancement without explicit sound stimuli, auditory structures in the ascending auditory pathway showed stronger signal enhancement in rats who received sound stimuli of 10 and 40 kHz. In addition, signal enhancement with a stimulation frequency of 40 kHz was stronger than that with 10 kHz. Therefore, the results of this study seem to suggest that, in order to achieve an effective response to high sound intensity or frequency, more firing of auditory neurons, or firing of many auditory neurons together for the pooled neural activity is needed.