External Sounds Research Articles

An IoT-enabled EEG headphones with customized music for chronic tinnitus assessment and symptom management

Chronic tinnitus often affects elderly or hearing-impaired individuals, which can disturb their daily lives by disrupting concentration and limiting communication. Clinically, sound masking using external sounds like white noise (WN) aims to mask tinnitus and relieve secondary symptoms. Even when symptoms are relieved, tinnitus often requires long-term management, and for patients to visit healthcare professionals regularly. Generally, it could make maintaining symptom management challenging due to the time and effort required for consistent follow-ups. EEG is considered as one of the objective marker for assessing tinnitus symptoms. In this study, we designed IoT-enabled EEG sensing (IEES) headphones, an innovative IoT device that provided customized music (CM) and EEG measurement. The headphones employed a pitch-matching (PM) method to create CM tailored to each patient at specific frequencies for tinnitus patients. To collect EEG measurements, the device incorporated OpenBCI electrodes and a sensing chip to monitor brain waves and evaluate the outcomes.. After 30 days of experiment, participants showed significant reductions in both tinnitus handicap inventory (THI) scores and visual analog scale for annoyance (VAS-A) scores. In comparison, tinnitus frequency showed a slight reduction. EEG measurements demonstrated an increase in alpha band activity. In questionnaires, patients reported high satisfaction with their experiences. These findings highlight the potential of the proposed method for chronic tinnitus assessment and symptom management.

Impaired speaking-induced suppression in schizophrenia predicts auditory verbal hallucinations.

A successful efference copy self-prediction suppresses auditory signals in the primary auditory cortex (A1) is necessary for speakers to successfully compare auditory feedback during speech production with auditory feedback during passive listening, this is called speaker-induced suppression (SIS). The top-rank positive symptom in schizophrenic (SZ) patients, auditory verbal hallucination, for instance, is hypothesized to relate to failure to distinguish the internal voice and external sounds, and this deficit is thought to be associated with impaired self-prediction in comparing external and self-generated contents. In this magnetoencephalographic imaging (MEGI) study, we compared SIS M100 in the primary auditory cortex (A1) between the healthy controls (HC; N = 30) and SZ patients (N = 22). The SZ patients displayed reduced SIS and M100 in the A1, and this impairment is negatively correlated with auditory hallucinations. These outcomes suggest that the SZ patients' hallucinatory symptoms are caused by misattribution between the external and self-generated stimuli. We proposed that the weakened self-agency and neural oscillations may lead to this misattribution.

Cerebellar activity predicts vocalization in fruit bats

Echolocating bats exhibit remarkable auditory behaviors, enabled by adaptations both within and outside their auditory system. Yet research on echolocating bats has focused mostly on brain areas that belong to the classic ascending auditory pathway. This study provides direct evidence linking the cerebellum, an evolutionarily ancient and non-classic auditory structure, to vocalization and hearing. We report that in the fruit-eating bat Carollia perspicillata, external sounds can evoke cerebellar responses with latencies below 20ms. Such fast responses are indicative of early inputs to the bat cerebellum. After establishing fruit-eating bats as a good model to study cerebellar auditory responses, we searched for a neural correlate of vocal production within the cerebellum. We investigated spike trains and field potentials occurring before and after vocalization and found that the type of sound produced (echolocation pulses or communication calls) can be decoded from pre-vocal and post-vocal neural signals, with prediction accuracies that reach above 85%. The latter provides a direct correlate of vocalization in an ancient motor-coordination structure that lies outside of the classic ascending auditory pathway. Taken together, our findings provide evidence of specializations for vocalization and hearing in the cerebellum of an auditory specialist.

Tunable active noise control circuit topology for multiple-feature applications

A tunable active-noise-control (ANC) circuit topology for headsets used in different applications is presented in this article. In the current consumer headset market, ANC is a mature technology that is commonly applied to wireless headsets connected to smartphones for listening to music and making phone calls. The development of ANC headsets has resulted in low-cost and simple devices due to the built-in ANC registers in the digital circuit. Digital circuit implementation is important to provide ultra-low latency processing for different algorithms compared with using digital signal processors (DSPs). However, a limitation associated with these built-in ANC filters is that the ANC digital circuit has been designed only for the wireless headset consumer market. Consequently, ANC headsets can only be used for designated features. ANC tuned for planes by eliminating low-frequency engine noise has been commonly used in the past twenty years. Pass-through (PT) amplification is also commonly tuned to allow users to hear external sounds and have conversations without having to remove their headset. In addition, ANC and PT amplification are also not allowed to operate simultaneously on the existing chipsets. In this paper, an ANC circuit topology with ultra-low latency processing is presented, where the ANC response of the headset can be tuned without any restriction imposed by the built-in ANC filters. The proposed ANC circuit topology consists of a commercial ANC chipset with an external audio codec to provide tunable characteristics. It is achieved by fixed maximum noise cancellation of ANC chipset being modified by summing with the signal from audio-codec path via an audio mixer. Acoustic performance for several headset applications implemented using the proposed circuit is validated. This simple circuit topology can be easily developed and adapted to the current headset consumer market for consumer-selective ANC in different environments.

The Prevalence of Insomnia Among Patients With Chronic Tinnitus in the General Population of the Kingdom of Saudi Arabia.

Tinnitus is a perception of sound without external sound stimulation. Subjective tinnitus is the most common type and is unrelated to external sounds. It is a symptom, not an illness, and is often linked to various psychological factors like anxiety and depression. Insomnia is a personal sense of difficulty falling asleep and issues with sleep initiation, length, consolidation, or quality while having ample chance to sleep, which impairs one's ability to function during the day. Sleep problems are prevalent in individuals with chronic tinnitus. We aimed to assess insomnia prevalence in chronic tinnitus patients in Saudi Arabia. Our study, an online cross-sectional survey, included 434 Saudi participants with chronic insomnia, utilizing a Google Forms questionnaire (Google LLC, Mountain View, California, United States). A total of 434 participants responded to the online survey. The most represented age group was 18-25 years, and 319 (73.5%) of the respondents were female. Approximately one-third (34.6%, n=150) were from the southern region. In the sample, 184 (42.4%) participants had bilateral tinnitus, and 105 (24.2%) had had tinnitus for over two years. Around 62.7% of the participants suffered from insomnia due to tinnitus. In terms of sleep quality, 174 (40.1%) participants took over 40 minutes to fall asleep, 85 (19.5%) were often afraid to sleep due to disturbed sleep, and 63 (14.5%) frequently used sleep pills. Our study of over 400 Saudi chronic tinnitus patients revealedthat a large percentage of tinnitus patients have insomnia, influenced by geographic region and tinnitus duration. Our findings offer valuable insights, emphasizing the necessity for additional research to inform interventions aimed at enhancing the quality of life of individuals with chronic tinnitus.

Device and Fitting Protocol for a Transitional Intervention for Debilitating Hyperacusis.

This report describes a hearing device and corresponding fitting protocol designed for use in a transitional intervention for debilitating loudness-based hyperacusis. The intervention goal is to transition patients with hyperacusis from their typical counterproductive sound avoidance behaviors (i.e., sound attenuation and limited exposure to healthy low-level sounds) into beneficial sound therapy treatment that can expand their dynamic range to the point where they can tolerate everyday sounds and experience an improved quality of life. This requires a combination of counseling and sound therapy, the latter of which is provided via the hearing device technology, signal processing, and precision fitting approach described in this report. The device combines a miniature behind-the-ear sound processor and a custom earpiece designed to maximize the attenuation of external sounds. Output-limiting loudness suppression is used to restrict exposure to offending high-level sounds while unity gain amplification maximizes exposure to healthy and tolerable lower level sounds. The fitting process includes measurement of the real-ear unaided response, the real-ear measurement (REM) system noise floor, the real-ear occluded response, real-ear insertion gain, and the output limit. With these measurements, the device can achieve the prescribed unity gain needed to provide transparent access to comfortable sound levels. It also supports individualized configuration of the therapeutic noise from an on-board sound generator and adaptive output limiting based on treatment-induced increases in dynamic range. The utility of this device and fitting protocol, in combination with structured counseling, is highlighted in the outcomes of a successful 6-month trial of the transitional intervention described in a companion report in this issue.

Duet synchronization interventions affect social interactions

Humans’ complex behavior, such as speech, music, or dance, requires us to coordinate our actions with external sounds as well as with social partners. The presence of a partner can influence individuals’ synchronization, and, in turn, social connection with the partner may depend on the degree of synchronization. We manipulated the synchronization quality in intervention conditions to address the causal relationship between observed temporal synchrony and perceived social interaction. Pairs of musician and nonmusician participants first performed a turn-taking task consisting of alternating which partner tapped their melody in synchrony with a metronome (each tap generated the next tone in the melody). In two intervention conditions, participants attempted to synchronize their melodies simultaneously with their partner, either with normal auditory feedback (normal feedback) or randomly placed delayed feedback on 25% of melodic tones (delayed feedback). After each intervention, the turn-taking condition was repeated, and participants completed a questionnaire about connectedness, relationship, and feeling of synchronization with their partner. Results showed that partners’ mean asynchronies were more negative following the delayed feedback intervention. In addition, nonmusician partners’ tapping variability was larger following the delayed feedback intervention when they had the delayed feedback intervention first. Ratings of connectedness, relationship, and feeling of synchronization with their partner were reduced for all participants after the delayed feedback Intervention. We modeled participants’ synchronization performance in the post-intervention turn-taking conditions using delay-coupling oscillator models. Reductions in synchronization performance after delayed feedback intervention were reflected in reduced coupling strength. These findings suggest that turn-taking synchronization performance and social connectedness are altered following short interventions that disrupt synchronization with a partner.

Attention-Modulated Cortical Responses as a Biomarker for Tinnitus.

Attention plays an important role in not only the awareness and perception of tinnitus but also its interactions with external sounds. Recent evidence suggests that attention is heightened in the tinnitus brain, likely as a result of relatively local cortical changes specific to deafferentation sites or global changes that help maintain normal cognitive capabilities in individuals with hearing loss. However, most electrophysiological studies have used passive listening paradigms to probe the tinnitus brain and produced mixed results in terms of finding a distinctive biomarker for tinnitus. Here, we designed a selective attention task, in which human adults attended to one of two interleaved tonal (500 Hz and 5 kHz) sequences. In total, 16 tinnitus (5 females) and 13 age- and hearing-matched control (8 females) subjects participated in the study, with the tinnitus subjects matching the tinnitus pitch to 5.4 kHz (range = 1.9-10.8 kHz). Cortical responses were recorded in both passive and attentive listening conditions, producing no differences in P1, N1, and P2 between the tinnitus and control subjects under any conditions. However, a different pattern of results emerged when the difference was examined between the attended and unattended responses. This attention-modulated cortical response was significantly greater in the tinnitus than control subjects: 3.9-times greater for N1 at 5 kHz (95% CI: 2.9 to 5.0, p = 0.007, ηp2 = 0.24) and 3.0 for P2 at 500 Hz (95% CI: 1.9 to 4.5, p = 0.026, ηp2 = 0.17). We interpreted the greater N1 modulation as local neural changes specific to the tinnitus frequency and the greater P2 as global changes to hearing loss. These two cortical measures were used to differentiate between the tinnitus and control subjects, producing 83.3% sensitivity and 76.9% specificity (AUC = 0.81, p = 0.006). These results suggest that the tinnitus brain is more plastic than that of the matched non-tinnitus controls and that the attention-modulated cortical response can be developed as a clinically meaningful biomarker for tinnitus.

Tinnitus: Clinical Insights in Its Pathophysiology-A Perspective

Tinnitus, the perception of sound without a corresponding external sound source, and tinnitus disorder, which is tinnitus with associated suffering, present a multifaceted clinical challenge due to its heterogeneity and its incompletely understood pathophysiology and especially due to the limited therapeutic options. In this narrative review, we give an overview on various clinical aspects of tinnitus including its heterogeneity, contributing factors, comorbidities and therapeutic pathways with a specific emphasis on the implications for its pathophysiology and future research directions. Tinnitus exhibits high perceptual variability between affected individuals (heterogeneity) and within affected individuals (temporal variability). Hearing loss emerges as predominant risk factor and the perceived pitch corresponds to areas of hearing loss, supporting the compensatory response theory. Whereas most people who have tinnitus can live a normal life, in 10–20% tinnitus interferes severely with quality of life. These patients suffer frequently from comorbidities such as anxiety, depression or insomnia, acting as both risk factors and consequences. Accordingly, neuroimaging studies demonstrate shared brain networks between tinnitus and stress-related disorders shedding light on the intricate interplay of mental health and tinnitus. The challenge lies in deciphering causative relationships and shared pathophysiological mechanisms. Stress, external sounds, time of day, head movements, distraction, and sleep quality can impact tinnitus perception. Understanding these factors provides insights into the interplay with autonomic, sensory, motor, and cognitive processes. Counselling and cognitive-behavioural therapy demonstrate efficacy in reducing suffering, supporting the involvement of stress and anxiety-related networks. Hearing improvement, especially through cochlear implants, reduces tinnitus and thus indirectly validates the compensatory nature of tinnitus. Brain stimulation techniques can modulate the suffering of tinnitus, presumably by alteration of stress-related brain networks. Continued research is crucial for unravelling the complexities of tinnitus. Progress in management hinges on decoding diverse manifestations, identifying treatment-responsive subtypes, and advancing targeted therapeutic approaches.

Overview Of Approach Control Unit Cabin Facilities Related To Noise

As an ATC, we should be able to give our full focus when providing air traffic services. If we cannot focus when working due to noise in the cabin, then the safety of the aircraft can also be threatened. Therefore, an ATC should get a work environment that can support his performance so that he can work optimally. This article delves into the challenges encountered by Air Traffic Controllers (ATCs) during their duties at the Tarakan Approach Control Unit, a crucial component of Juwata International Airport in Tarakan, North Kalimantan, Indonesia. The study revolves around the adverse effects of excessive noise levels within the ATC cabin on controller performance and aviation safety. Through qualitative descriptive methodology, this study explores the factors contributing to the noise problem within the Tarakan APP cabin. It identifies two major sources of noise: gaps in windows and doors, permitting external sounds to infiltrate the cabin, and the lack of sound insulation in the flooring. The results section introduces alternative solutions proposed by the author to mitigate the noise issue and enhance the ATC work environment. These solutions encompass the use of headsets, transitioning to a Voice Communication Control System (VCCS), installing sound-absorbing materials on the cabin floor, and incorporating UPVC to seal gaps in windows and doors. In conclusion, this study highlights the critical need for an enabling work environment that supports ATCs in ensuring aviation safety. The author encourages relevant authorities to consider and implement the proposed solutions to establish a more efficient, effective, safe, and comfortable air traffic control environment at Tarakan APP, ultimately benefiting air navigation services.

Tinnitus characteristics and risk factors in the Bali region

Introduction: It has been recognized that suitable external sounds can reduce or even make tinnitus impossible to hear. The working principle of sound therapy will be used to create a new tool or approach that suits the conditions of Indonesian society. This study aimed to describe the characteristics of tinnitus and its associated risk factors. Method: This was a cross-sectional study conducted in Denpasar City, Gianyar Regency, and Badung Regency for one year. Patients who visited the ENT doctors' practices in these areas were interviewed with prepared instruments. The patients were then subjected to clinical and audiometric examinations. The data will be analyzed descriptively to get an overview of tinnitus's sociodemographic and clinical characteristics. Result: A total of 101 participants were included in this study. Most tinnitus patients were unilateral on the left side of the ear. The most common sound is ringing, up to 70.3% of 101 research subjects, followed by sound types such as pulse and roaring sound. Furthermore, the frequency and amplitude of tinnitus sounds are quite varied, but the majority is dominated by high frequencies (3000 - 8000Hz). Based on the ear affected, the largest number of tinnitus sufferers were found in the left ear (47.0%). In this study, 82 people (81.2%) had a history of frequently using earphones, while 19 other people never used earphones in everyday life. Among all participants, 95 people (94.1%) were not exposed to noise at work. Conclusion: The clinical characteristics of the tinnitus sound type were mostly ringing sounds, followed by pulse-like sounds and buzzing sounds. The frequency and amplitude of tinnitus sounds quite varied. Stress factors and the use of earphones occur in most tinnitus sufferers.

DOES MUSIC AFFECT THE UNBORN CHILD?

During pregnancy, the level of concern about the possibility of harming the development of the fetus is usually high in both pregnant women and their doctors. Household influences, such as music, may also be perceived as beneficial or dangerous depending on their nature. In the above review, an attempt is made to analyze the degree of actual scientific background on this issue. Evidence of the possibilities of the influence of external sounds on the state of the fetus, known facts of the long-term consequences of such an impact are given, an analysis of the possible difference in the effect exerted by music of different musical genres is carried out.

Tinnitus as central noise revealed by increased loudness at thresholds

Tinnitus is an auditory sensation in the absence of external sounds; its neural mechanisms remain unclear. An active loudness model suggests that tinnitus is a result of increased central noise while hyperacusis is that of increased central gain. To the extent that loudness reflects the system-level neural activities, this active model predicts that tinnitus increases loudness at thresholds but does not increase the slope of loudness function. To test this prediction, the present study compared loudness growth of various stimuli between tinnitus and non-tinnitus subjects. The stimuli were tested at frequencies without hearing loss and both tinnitus and non-tinnitus subjects had unremarkable hyperacusis. Consistent with the prediction, the loudness at threshold in tinnitus subjects were 2.3 times greater than that in non-tinnitus subjects; there was no significant difference in the slope of loudness growth between these two groups of subjects. The present result shows that traditional psychophysics, originally developed to investigate relationships between subjective sensation and physical stimulation, can also help delineate neural mechanisms underlying tinnitus and other disorders.

Discovering ecoacoustic codes in beehives: First evidence and perspectives

The sounds present inside a beehive originate from the overlap of honeybee buzzes with external sounds. They reveal patterns that support the hypothesis that the sonic context of the beehive may be utilized by honeybees as a source of ecoacoustic codes for communication and the coordination of social activity. Patterns were observed in a data series of acoustic files sampled at a frequency of 48 kHz during the period May–July 2023 in a beehive of Apis mellifera ligustica (Spinola, 1806). The acoustic information was extracted using the acoustic complexity index (ACItf) algorithm applied to a fast Fourier transform matrix. Data series, aggregated in 1368 min × 512 frequency bins × 61 days, were tentatively classified according to three temporal classes of aggregation (eight, six, and four clusters, respectively) using the hierarchical K-means clustering algorithm. The clusters obtained at these three resolutions were considered potential ecoacoustic codes (PECs) belonging to each minute of the data series.The number of discontinuities along the 24-h PEC sequence, the coefficient of variation of the number of PECs at daily and seasonal scales, and the PEC sample entropy confirmed a patterned distribution of PECs across the 24 h, modulated at a monthly scale. A significant correlation was found between these indices and the daily average wind speed, and temperature. Honeybee buzz is an informative medium used by honeybees to develop survival strategies.

An Investigation in the Measurable Differences between Pitch Perception in the Voice and Pitch Perception of External Sound Sources

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

Adding Sound Transparency to a Spacesuit: Effect on Cognitive Performance in Females.

Spacesuits may block external sound. This induces sensory deprivation; a side effect is lower cognitive performance. This can increase the risk of an accident. This undesirable effect can be mitigated by designing suits with sound transparency. If the atmosphere is available, as on Mars, sound transparency can be realized by augmenting and processing external sounds. If no atmosphere is available, such as on the Moon, then an Earth-like sound can be re-created via generative AR techniques. We measure the effect of adding sound transparency in an Intra-Vehicular Activity suit by means of the Koh Block test. The results indicate that participants complete the test more quickly when wearing a suit with sound transparency.

Psychological Profile and Social Behaviors of Patients with Hyperacusis.

Increased noise sensitivity refers to the abnormal subjective response to external sounds, with a prevalence of between 8% and 15.2% in the adult population as suggested by epidemiological studies. The basic neural mechanism of hyperacusis still remains obscure, so therapies for this often-devastating symptom remain elusive. The aim of this study was to assess psychological profiles in patients with presbycusis without tinnitus in a perspective case-control design. All subjects were initially submitted to audiological evaluation (tympanometry, recordings of the acoustic reflex thresholds, pure tone audiometry) and subsequently were administered the following questionnaires: the hyperacusis questionnaire (HQ), the brief symptom inventory (BSI), and the modified somatic perception questionnaire (MSPQ). Patients with hyperacusis reported a total score and subscales (attentional, social, and emotional) of the HQ significantly higher than controls. They also reported higher scores of the MSPQ and significantly higher mean values with concern to the somatization, obsessive-compulsive, interpersonal sensitivity, depression, and anxiety subscales of the BSI. These results show that psychological distress, as expressed by higher level of somatic attention, somatization, anxiety, and depression, is a significant factor to consider for a complete diagnosis and effective treatment of hyperacusis. For a correct diagnosis of patients seeking help for hyperacusis, their psychological distress should also be assessed, regardless of their hearing abilities. Further studies are required to investigate the pathological mechanisms that are involved in the onset of hyperacusis in patients with normal hearing and those with sensorineural hearing loss.

Pilot study on the role of somatic modulation in hyperacusis.

Hyperacusis is a reduced tolerance to sounds that often co-occurs with tinnitus. Both symptoms have convergent as well as divergent characteristics. Somatic modulation, changes in pitch or loudness during certain movements, is common in patients with a primary complaint of tinnitus. However, thus far, this is not documented in patients with hyperacusis. This study aimed to examine the influence of somatic manoeuvres on the perception of external sounds in patients with a primary complaint of hyperacusis. In this prospective cross-sectional pilot study, 18 patients with a primary complaint of hyperacusis were recruited at the Tinnitus Treatment and Research Center Antwerp (TINTRA). While patients listened to a 1kHz broadband noise of 30dB sensation level, six neck manoeuvres (flexion, extension, lateroflexion left/right, traction and compression), three jaw manoeuvres (protrusion, laterotrusion left/right) and one placebo manoeuvre (hand on head) were performed. The primary outcome measure was the change in the perception of the presented sound in terms of loudness and intrusiveness between baseline and each modulation measured by a visual analogue scale (VAS). No overall significant changes were found; however, individual results indicated that five patients presented a clinically relevant change of more than three points out of ten on VAS in terms of hyperacusis after at least one of the executed somatic manoeuvres. This pilot study did not demonstrate an overall significant change in hyperacusis after somatic manoeuvres but does not rule out the possibility of somatic modulation in some hyperacusis patients. The protocol of this prospective cross-sectional pilot study was registered on clinicaltrials.gov with registration number NCT04693819.

Spectral changes to sound exposure when preterm infants transition from the incubator to an open crib

Children born preterm are at risk for speech and language developmental delays and disorders. It has been proposed that adverse auditory exposures during stay in the neonatal intensive care unit (NICU) may contribute to this risk, as it is well-established that the preterm infant’s developing auditory system is sensitive to acoustic input during this time. While reduced speech exposure, noxious noise levels, and excessive silence in the NICU are of concern, another potential cause for concern is abrupt changes in auditory exposure during NICU stay. Our previous data indicate that NICU incubator walls have a low-pass filtering effect, attenuating external sounds at frequencies above 200 Hz. However, internal sounds generated by the incubator or other life-saving devices still produce noise exposure. Furthermore, when infants transition to an open crib from the incubator based on improved overall health, they may be at risk of increased exposure to higher frequencies. Here we present spectral analyses of auditory exposure recordings made for several preterm infants throughout NICU stay. Our analysis reveals that for frequencies above 500 Hz, sound levels are significantly higher in the open crib; below 500 Hz, levels are generally higher in the incubator. These data point to yet another potentially disruptive effect of the NICU environment caused by an abrupt change in auditory exposure.

The Effect of Music Intervention on Fetal Education via Doppler Fetal Monitor.

This study focused on the effects of music intervention on fetal education in pregnant women. The fetal heart rate of the fetus at 30–38 weeks of gestational age was monitored by an ultrasound Doppler fetal monitor, and differences in the frequency of fetal movement responses to familiar and unfamiliar music courses were recorded and analyzed. The analysis results showed that the fetuses had less fetal movement to fixed singing activities, with a mean of 0.7 and a standard deviation of 0.79. On the contrary, the fetuses had significant fetal movement responses to irregular singing, with a mean of 1.73 and a standard deviation of 1.37. The results showed that the fetus receives external sounds through hearing, and a pregnant woman singing fixed music to her fetus can stabilize the frequency of fetal movement, promote the health of herself and the fetus, and establish maternal-fetal bonding.