Baseline Noise Level Research Articles

Quieting the neonatal intensive care unit: A quality improvement initiative.

The neonatal intensive care unit (NICU) is vital for preterm infants but is often plagued by harmful noise levels. Excessive noise, ranging from medical equipment to conversations, poses significant health risks, including hearing impairment and neurodevelopmental issues. The American Academy of Pediatrics recommends strict sound limits to safeguard neonatal well-being. Strategies such as education, environmental modifications, and quiet hours have shown to reduce noise levels. However, up to 60% of the noises remain avoidable. High noise exposure exacerbates physiological disturbances, impacting vital functions and long-term neurological outcomes. Effective noise reduction in the NICU is crucial for promoting optimal neonatal development. To measure the sound levels in a NICU and reduce ambient sound levels by at least 10% from baseline. A quasi-experimental quality improvement project was conducted over 4 mo in a 20-bed level 3 NICU in a tertiary care medical college. Baseline noise levels were recorded continuously using a sound level meter. The interventions included targeted education, environmental modifications, and organizational changes, and were implemented through three rapid Plan-Do-Study-Act (PDSA) cycles. Weekly feedback and monitoring were conducted, and statistical process control charts were used for analysis. The mean noise values were compared using the paired t-test. The baseline mean ambient noise level in the NICU was 67.8 dB, which decreased to 50.5 dB after the first cycle, and further decreased to 47.4 dB and 51.2 dB after subsequent cycles. The reduction in noise levels was 21% during the day and 28% at night, with an overall decrease of 25% from baseline. The most significant reduction occurred after the first PDSA cycle (mean difference of -17.3 dB, P < 0.01). Peak noise levels decreased from 110 dB to 88.24 dB after the intervention. A multifaceted intervention strategy reduced noise in the NICU by 25% over 4 months. The success of this initiative emphasizes the significance of comprehensive interventions for noise reduction.

Noise in operating theatres, is it safe?

Noise-Induced Hearing Loss (NIHL) is a condition caused by repeated exposure to loud noise, with operating theatre personnel potentially at risk. The aims of this study were to establish the typical noise levels in orthopaedic theatres and to compare these to The Control of Noise at Work Regulations 2005. We measured the average noise levels in 40 trauma and orthopaedic surgeries in a single centre. We used the Decibel X app to take measurements, then performed corrections to ascertain noise levels at the surgeon's ear (Leq). The daily noise exposure level for theatre staff for each procedure (LEP, d) and the LEP, d over an average 8-hour working day when performing different groups of procedures were calculated. Data were analysed using descriptive statistics, ANOVA, t-test and the Pearson coefficient of correlation. The LEP, d lower action value (80 dBA) as set by the Health and Safety Executive (HSE) was met by performing a single revision total knee replacement or a right open ankle debridement. Assuming three procedures are conducted per list, lists consisting of joint replacements (82 dBA) or medium elective procedures (81 dBA) exceed this lower limit. Additionally, lists comprising large and medium bone fractures would be within 1 dB of the limit (79 dBA and 79 dBA, respectively). Soft tissue (74 dBA), arthroscopic (73 dBA), and small bone fracture (71 dBA) procedures had the lowest LEP, d. The greatest contributors to noise levels were surgical instruments. The number of people in the room made a significant difference to noise levels (p = 0.032). We have established the baseline noise levels in various orthopaedic procedures. Measures should be taken to meet UK regulations. Further research should determine suitable measures for protection from hearing damage for theatre staff and evaluate the risks high noise levels pose to patients.

Comparison of Frequency-Domain and Time-Domain Baseline Correction Approaches for Infrared Absorption Spectroscopy of Mixtures Containing Up to 464 Components.

Many baseline correction approaches have been developed to address baseline artifacts observed in measured infrared (IR) absorption spectra during post-processing. These approaches offer distinct advantages and disadvantages, and the choice of which one to employ depends on the complexity of baseline artifacts present in a particular application. In this paper, we compare the performance of two baseline correction approaches: a frequency-domain polynomial fitting approach and a time-domain modified free induction decay approach, under various baseline scenarios, spectral resolutions, and noise levels for mixtures containing up to 464 species. Our results showed that the frequency-domain approach outperformed the time-domain approach by a factor of up to 16 when the baseline was represented by a sine wave with fewer than two cycles over the full spectral range. On the other hand, the time-domain approach performed up to 12 times better when the baseline featured two cycles of a sine wave. Additionally, we observed that the time-domain approach exhibited higher sensitivity to spectral resolution and underperformed when the noise level was high. The findings of this study emphasize the importance of numerically testing a few candidate approaches for a given application, taking into consideration baseline characteristics, as well as the spectral resolution and noise constraints of the application.

Analysis of noise levels in the neonatal intensive care unit: the impact of clinical microsystems.

Reorganization of neonatal intensive care by introducing clinical microsystems may help to allocate nursing time more appropriately to the needs of patients. However, there is concern that cohorting infants according to acuity may enhance noise levels. This single-center study investigated the impact of reorganization of neonatal intensive care unit by implementing clinical microsystems in a Level III NICU on environmental noise. This prospective study measured 24-h noise levels over a period of 6months during pre- and post-implementation of microsystems cohorting infants of similar acuity. Comparative analyses of the mixed acuity (i.e., before) and the cohorting (i.e., after) model were performed by creating daily profiles from continuous noise level measurements and calculating the length of exposure to predefined noise levels. Compared to baseline daytime measurements, noise levels were 3-6 dBA higher during physician handover. Noise levels were 2-3 dBA lower on weekends and 3-4 dBA lower at night, independent of the organizational model. The introduction of clinical microsystems slightly increased average noise levels for high-acuity pods (A and B) but produced a much more substantial decrease for low-acuity pods (E), leading to an overall reduction in unit-wide noise levels. Conclusion: Our data show that noise levels are more driven by human behavior than by technical devices. Implementation of microsystems may help to reduce noise exposure in the lower acuity pods in a NICU. What is Known: • Excessive noise levels can lead to adverse effects on the health and development of premature infants and other critically ill newborns. • The reorganization of the neonatal intensive care unit following the clinical microsystems principles might improve quality of care but also affect noise exposure of staff and patients. What is New: • The transition from a mixed -acuity to cohorting model is associated with an overall reduction in noise levels, particularly in low-acuity pods requiring less nursing care. • Nevertheless, baseline noise levels in both models exceeded the standard permissible limits.

Relationship between noise levels and intensive care patients' clinical complexity: An observational simulation study.

Noise pollution in intensive care units is a relevant problem, associated with psychological and physiological consequences for patients and healthcare staff. Sources of noise pollution include medical equipment, alarms, communication tools, staff activities, and conversations. To explore the cumulative effects of noise caused by an increasing number and type of medical devices in an intensive care setting on simulated patients with increasing clinical complexity. Secondly, to measure medical device alarms and nursing activities' sound levels, evaluating their role as potentially disruptive noises. Observational simulation study (reported according to the STROBE checklist). Using an electronic sound meter, the sound levels of an intensive care room in seven simulated clinical scenarios were measured on a single day (09 March 2022), each featuring increasing numbers of devices, hypothetically corresponding to augmented patients' clinical complexity. Secondly, noise levels of medical device alarms and specific nursing activities performed at a distance of three meters from the sound meter were analysed. The empty room's mean baseline noise level was 37.8 (±0.7) dBA; among the simulated scenarios, noise ranged between 45.3 (±1.0) and 53.5 (±1.5) dBA. Alarms ranged between 76.4 and 81.3 dBA, while nursing tasks (closing a drawer, opening a saline bag overwrap, or sterile packages) and speaking were all over 80 dBA. The noisiest activity was opening a sterile package (98 dBA). An increased number of medical devices, an expression of patients' higher clinical complexity, is not a significant cause of increased noise. Some specific nursing activities and conversations produce higher noise levels than medical devices and alarms. This study's findings suggest further research to assess the relationships between these factors and to encourageadequate noise reduction strategies. Excessive noise level in the intensive care unit is a clinical issue that negatively affects patients' and healthcare providers' well-being. The increase in baseline room noise from medical devices is generally limited. Typical nursing tasks and conversations produce higher noise levels than medical devices and alarms. These findings could be helpful to raise awareness among healthcare professionals to recognize noise sources. The noisiest components of the environment can be modified by staff behaviour, promoting noise reduction strategies and improving the critical care environment.

Improve sleep in critically ill patients: Study protocol for a randomized controlled trial for a multi-component intervention of environment control in the ICU.

In critically ill patients, sleep and circadian rhythms are greatly altered. These disturbances have been associated with adverse consequences, including increased mortality. Factors associated with the ICU environment, such as exposure to inadequate light and noise levels during the day and night or inflexible schedules of daily care activities, have been described as playing an essential role in sleep disturbances. The main objective of this study is to evaluate the impact of the use of a multifaceted environmental control intervention in the ICU on the quantity and quality of sleep, delirium, and post-intensive care neuropsychological impairment in critically ill patients. This is a prospective, parallel-group, randomized trial in 56 critically ill patients once they are starting to recover from their acute illness. Patients will be randomized to receive a multifaceted intervention of environmental control in the ICU (dynamic light therapy, auditory masking, and rationalization of ICU nocturnal patient care activities) or standard care. The protocol will be applied from enrollment until ICU discharge. Baseline parameters, light and noise levels, polysomnography and actigraphy, daily oscillation of plasma concentrations of Melatonin and Cortisol, and questionnaires for the qualitative evaluation of sleep, will be assessed during the study. In addition, all patients will undergo standardized follow-up before hospital discharge and at 6 months to evaluate neuropsychological impairment. This study is the first randomized clinical trial in critically ill patients to evaluate the effect of a multicomponent, non-pharmacological environmental control intervention on sleep improvement in ICU patients. The results will provide data about the potential synergistic effects of a combined multi-component environmental intervention in ICU on outcomes in the ICU and long term, and the mechanism of action. ClinicalTrials.gov, NCT. Registered on January 10, 2023. Last updated on 24 Jan 2023.

PO-04-230 IMPROVED VISUALIZATION OF LOW AMPLITUDE LATE POTENTIALS WITH VT SUBSTRATE MAPPING USING A NOVEL EP RECORDING SYSTEM

Accurate identification of low-voltage electrograms (EGMs) suffer from artifacts that often interfere with physiological signals in the <0.1-0.5mV range. For substrate based ablation of ventricular tachycardia (VT), dense scar is defined as regions of myocardium with EGM amplitudes below 0.5 mV. Within these regions, current EP recording systems can fail at identifying low-voltage late potentials that are effective targets of ablation therapy. More recently, new EP amplifiers designed specifically to reduce the impact of interference on the fidelity of signals have been introduced. This study used a novel EP recording system (ECGenius System, CathVision, Copenhagen, DK) to identify low amplitude (<0.5mV) late potentials in regions of scar, and quantify their characteristics in a head-head comparison to a standard recording system (LabSystem Pro, Boston Scientific, MA). We collected recordings in parallel from four patients (30-250 Hz bipolar recording bandwidth) referred to our center for an EP study and ablation for VT. We performed substrate mapping during sinus rhythm with a standard 4mm irrigated ablation catheter (SmartTouch, Biosense Webster, Diamond Bar, CA) and a multi-spline mapping catheter (PentaRay, Biosense Webster). In regions of dense scar (< 0.5 mV, delineated with 3-D electroanatomical mapping) we identified late potentials that were above the baseline noise level of the CathVision system that were otherwise not clearly visible with the LabSystem Pro system. In four patients we identified fourteen sites with late potentials (110 beats) that were only identified with the CathVision System (see figure). The average amplitude of the late signals was 0.079 +/- 0.063 mV, which was above the baseline mean noise of 0.008 mV (range 0.006 to 0.015 mV). In contrast, the baseline mean noise of the LabSystem Pro was 0.060 mV (range 0.040 to 0.090 mV). The mean delay of the late potentials (after the start of the surface ECG QRS) was 377ms (range 198 to 470ms). Improved visualization of low voltage EGMs and late potentials can improve upon substrate-based ablation of ischemic VT. With a novel, and state-of-the art recording amplifier, we demonstrate an improved ability to detect clinically relevant sites for ablation that were not visible with a standard recording system. This technology could improve upon current ablation strategies, and may be particularly useful in the current era of micro-electrodes and relatively smaller recording voltages.

A Quality Improvement Pilot Project for Noise Reduction in the NICU.

Increased noxious noise leads to adverse short-term and long-term effects on the growing neonate. The American Academy of Pediatrics recommends maintaining a noise level of less than 45 decibels (dBA). The average baseline noise level in an open-pod neonatal intensive care unit (NICU) was 62.6 dBA. The purpose of this pilot project was to reduce the average noise levels by 39% at the end of an 11-week period. The location of the project was in a large, high-acuity level IV open-pod layout NICU that consisted of 4 pods, one of which was cardiac-focused. The average baseline noise level in the cardiac pod was 62.6 dBA in a 24-hour period. Noise levels were not monitored before this pilot project. This project was implemented over an 11-week period. Several modes of education were used for parents and staff. Post-education, Quiet Times were implemented at set times twice daily. Noise levels were monitored for 4 weeks during Quiet Times, with weekly noise level updates for staff. General noise levels were collected a final time to evaluate the overall change in the average noise levels. At the end of the project, noise levels decreased from 62.6 dBA to 54 dBA, a 13.7% reduction. At the end of this pilot project it was noted that: Online modules were the best way to educate staff. Parents should be included in the implementation of quality improvement. Healthcare providers need to know and understand that they can make preventative changes to improve the outcomes of the population.

Noise in cesarean deliveries: a comprehensive analysis of noise environments in the Labor and Delivery operating room and evaluation of a visual alarm noise abatement program

Cesarean deliveries are the most common major surgery worldwide. Noise in healthcare settings leads to impaired communication, concentration, and stress among health care providers. Limited information is available about noise at cesarean delivery. Our aim was to achieve a comprehensive analysis of noise that occurs during cesarean deliveries. Sound level meters are used to determine baseline noise levels and to describe the frequency of acute noise that is generated during a cesarean that will cause a human startle response. Secondarily, we will evaluate the effectiveness of a visual alarm system to mitigate excessive noise. We completed a pre-intervention/post-intervention observational study of noise levels during cesarean deliveries before and after introduction of a visual alarm system for noise mitigation between 2/15/2021 to 8/26/2021. There were 156 cases included from each study period. Sound pressure levels were analyzed by overall case median decibel levels and by time epoch for relevant phases of the operation. Rapid increase noise events capable of causing a human startle response, "Startle events" were detected a by retrospective analysis, with quantification for baselines and analysis of frequency by case type. Median noise levels with inter-quartile ranges [I.Q.R.] are presented. Data are compared between epochs and case characteristics with non-parametric two-tailed testing. The median acoustic pressure for all cesarean deliveries was 61.8 [58.8, 65.9] dBA (median [I.Q.R.]). The median dBA for the full case time period was significantly higher during cases with NICU team presence, 62.1 [60.5, 63.9]; neonatal admission to the NICU, 62.0 [60.4, 63.9]; 5-minute APGAR score less than 7, 62.2 [61.1, 64.3]; multiple gestations, 62.6 [62.0, 64.2]; and intraoperative tubal sterilization, 62.8 [61.5, 65.1]. The use of visual alarms was associated with a statistically significant reduction of median noise level by 0.7 dBA, from 61.8 [60.6, 63.5] dBA to 61.1 [59.8, 63.7] dBA, (p<0.001). The noise intensities recorded during cesarean deliveries were commonly at levels that affect communication and concentration, and above the safe levels recommended by the W.H.O. Although noise was reduced by 0.7 dBA, the reduction was not clinically significant to reduce noise a discernible amount (a 3dB change) nor in reducing "startle events". Isolated use of visual alarms during cesarean deliveries is unlikely to be a satisfactory noise mitigation strategy.

Results from The Quiet Project - UK Acoustic Community's response to Covid-19

The COVID-19 Lockdown created a new kind of environment both in the UK and globally, never experienced before or likely to occur again. A vital and time-critical working group was formed with the aim of gathering crowd-source high quality baseline noise levels and other supporting information across the UK during the lockdown and subsequent recovery period. The acoustic community were mobilised through existing networks (UK Acoustics Network, Association of Noise Consultants, and Institute of Acoustics) engaging private companies, public organisations, and academics to gather data in accessible places. A website was designed and developed to advertise the project, provide instructions and to formalise the uploading of noise data, observations, and Soundscape feedback. The data was collected at 99 locations by 80 acousticians (64 male, 16 female) using professional grade calibrated instrumentation with 83% of measurements including spectral data. The locations were spread across the British Isles covering 19 urban, 61 suburban, and 19 rural sites. The Lockdown 1 dataset consisted of a total of 1.6 GB of measurements and material (video, photos) covering 834 days between 1st April and 14th July 2020. This makes the award winning Quiet Project the largest ever noise and soundscape database ever recorded. As a government-funded research project the databank will be made publicly available to assist future research.

Ultrathin Gold Microelectrode Array using Polyelectrolyte Multilayers for Flexible and Transparent Electro‐Optical Neural Interfaces

AbstractElectro‐optical neural interface technologies provide great potential and versatility in neuroscience research. High temporal resolution of electrical neural recording and high spatial resolution of optical neural interfacing such as calcium imaging or optogenetics complimentarily benefit the way information is accessed from neuronal networks. To develop a hybrid neural interface platform, it is necessary to build transparent, soft, flexible microelectrode arrays (MEAs) capable of measuring electrical signals without light‐induced artifacts. In this work, flexible and transparent ultrathin (&lt;10 nm) gold MEAs are developed using a biocompatible polyelectrolyte multilayer (PEM) metallic film nucleation‐inducing seed layer. With the polymer seed layer, the thermally evaporated ultrathin gold film shows good conductivity while providing high optical transmittance and excellent mechanical flexibility. In addition, strong electrostatic interaction via the PEM alters the electrode‐electrolyte interfaces, thereby reducing the electrode impedance and baseline noise level. With a simple modification of the fabrication process of the MEA using biocompatible materials, both excellent transmittance, and electrochemical interface characteristics are achieved, which is promising for efficient electro‐optical neural interfaces.

Preparation and evaluation of a polymer-based sulfobetaine zwitterionic stationary phase

We describe a polymer-based sulfobetaine zwitterionic stationary phase for hydrophilic interaction liquid chromatography (HILIC). It was prepared by grafting acrylamide-type sulfobetaine monomer instead of common methacrylate-type sulfobetaine onto hydrolysed poly (glycidyl methacrylate-divinylbenzene) (GMA-DVB) microspheres via pendant double bonds of DVB. The phase has been characterized by elemental analysis, scanning electron micrograph and N2 adsorption-desorption experiment. It shows wider pH tolerance range (from 2 to 12) and excellent separation ability towards common strong polar analytes such as nucleosides and nucleic bases, water-soluble vitamins, amino acids, inorganic anions and cations. Notably, it exhibits negligible baseline noise level (~0.15 pA) under typical HILIC mobile phase. Excellent selectivity in separation of α- and β-anomers of reducing sugars and lactose/lactulose has also been observed.

The quiet project-UK acoustic community’s response to COVID-19

The COVID-19 Lockdown created a new kind of environment both in the UK and globally, never experienced before or likely to occur again. A vital and time-critical working group was formed with the aim of gathering crowd-source high quality baseline noise levels and other supporting information across the UK during the lockdown and subsequent recovery period. The acoustic community were mobilised through existing networks engaging private companies, public organisations, and academics to gather data in accessible places. A website was designed and developed to advertise the project, provide instructions and to formalise the uploading of noise data, observations, and Soundscape feedback. In addition, pre-existing on-going measurements from major infrastructure projects, airport, and planning applications were gathered to create a data repository of 1.6 GB. The plan was to have regular 6 monthly national noise surveys, which turned into multiple Lockdown surveys. Noise data has been compared to the traffic flow data from the TRIS national wide permanent monitoring system. Ultimately, the databank will be used to establish the relation to other impacts such as air quality, air traffic, economic, and health and wellbeing. As publicly funded research the databank will be made publicly available to assist future research.

The Quiet Project – UK Acoustic Community’s response to COVID19 during the easing of lockdown

Abstract The COVID-19 lockdown created a new kind of environment both in the UK and globally, never experienced before or likely to occur again. A vital and time-critical working group was formed with the aim of gathering crowd-source high quality baseline noise levels and other supporting information across the UK during the lock-down and subsequent periods. The acoustic community were mobilised through existing networks engaging private companies, public organisations and academics to gather data in accessible places. In addition, pre-existing on-going measurements from major infrastructure projects, airport, and planning applications were gathered to create the largest possible databank. A website was designed and developed to advertise the project, provide instructions and to formalise the uploading of noise data, observations and soundscape feedback. Two case studies gathered in the latter stage of full lockdown are presented in the paper to illustrate the changes in the environmental noise conditions relative to transport activity. Ultimately the databank will be used to establish the relation to other impacts such as air quality, air traffic, economic, and health and wellbeing. As publicly funded research the databank will be made publicly available to assist future research.

Efficacy of noise reduction bundle in reducing sound levels in a Level II neonatal care unit in China.

BackgroundNoise is a hazard for newborns. Preterm infants are more vulnerable to negative effects of noise because their auditory system is at a critical period of neurodevelopment. We conducted this study to determine whether noise exposure in our Level II unit met the American Academy of Pediatrics (AAP)-issued recommendation of less than 45 dB. We also aimed to assess the efficacy of a bundle of noise reduction methods and the role of noise supervisors in assuring the compliance of modification.MethodsHourly mean equivalent continuous noise level (Leq) was collected in two phases: (I) Phase 1: baseline data for 4 weeks, (II) Phase 2: study period for 13 weeks, 1 week (Stage 1) under close monitoring by the noise supervisors and 12 weeks (Stages 2, 3 and 4, lasting 4 weeks each) without supervisors.ResultsThe baseline noise level consistently exceeded recommendations with an hourly mean incubator noise of 53.6 dB (±5.2). Our bundle resulted in a significant reduction in incubator noise levels by 9.1 dB (±0.75). The sound levels remained <45 dB most of the time except for three-time windows, correlating with morning handovers/physical assessments (7:00–9:00), procedures/discharges/phone calls (13:00–15:00), and night handovers (19:00–20:00). The change in the reduction was most significant (–4.1 dB) in Stage 1 during the day shift. A minor trend of decline in sound levels inside the incubator was observed from Stage 1 to Stage 2 (P=0.057), with a rebound occurring in Stage 3 followed by stabilization in Stage 4, suggesting the role of noise supervisors in ensuring the compliance of the modification.ConclusionsThe baseline noise levels consistently exceeded recommendations, but the bundle was effective in achieving the reduction. Noise supervisors are essential to ensure the compliance of the modification. Resolution focused on the three-time windows is required in future work.

Can Wavelet Denoising Improve Motor Unit Potential Template Estimation?

Background: Electromyographic (EMG) signals obtained from a contracted muscle contain valuable information on its activity and health status. Much of this information lies in motor unit potentials (MUPs) of its motor units (MUs), collected during the muscle contraction. Hence, accurate estimation of a MUP template for each MU is crucial.Objective: To investigate the possibility of improving MUP template estimation using the wavelet denoising technique.Material and Methods: In this analytical study, several MUP template estimators were developed by combining conventional estimation methods and wavelet denoising techniques. A MUP template was initially estimated using conventional methods such as mean, median, median-trimmed mean, or mode. Thereafter, it was post-processed using the wavelet denoising technique. Results: Evaluation results of the studied estimators using 40 simulated EMG signals with a true template for each constituent MUP train showed that augmented wavelet- based template estimation methods are more reliable than conventional methods. However, on average, wavelet denoising was not much effective. Around 40 MUPs of a MU is sufficient to estimate its MUP template.Conclusions: Although wavelet techniques are effective in EMG signal analysis, here wavelet denoising did not practically improve MUP template estimation. Considering computational simplicity and estimation error, the two methods median and median-trimmed mean are practical estimators that can provide a good estimation of a MUP template for a MU when approximately 40 MUPs are available. Nevertheless, the baseline noise level in the MUP templates estimated using the median-trimmed mean method is slightly lower than that in the templates estimated using the median method.

Comparison between noise levels inside and outside neonatal incubators: Implications for neonatal care in India

Background: The neonatal unit equipment generates noise which is detrimental to neonatal physiological homeostasis and development. The incubator is one such essential component of modern neonatal care which, on the one hand, provides a low noise environment and also intrinsically generates noise. Objectives: The objectives of the study were to test the hypothesis that the neonatal incubator provided a better acoustic environment with lesser noise levels than the external environment. Materials and Methods: A prospective observational study was done in a Level III neonatal unit for 4 months from April 15, 2016, to August 15, 2016. Baseline noise levels of the various equipment inside a working incubator were recorded using a sound level meter. Subsequently, hourly noise levels in the neonatal intensive care unit (NICU) and inside the Giraffe Omnibed Incubator were recorded simultaneously as equivalent Continuous Sound Pressure Level as loudness equivalent. Two digital sound level meters were used. Noise levels inside and outside the incubators were used as a grouping variable. Chi-square test was used for categorical variables and independent t-test for continuous variables. All tests were two tailed and p&lt;0.05 was considered statistically significant. Results: The noise levels recorded both inside the incubator and the NICU were &gt;58 dbA for most times of the day. The noise levels inside the incubator were significantly less (p&lt;0.05) than the outside. Conclusion: The statistically significant noise reduction inside the incubator provides a better acoustic environment for neonates.

Determinants of noise level in the neonatal intensive care unit at Castle Street Hospital for Women, Colombo, a level III tertiary care facility

Introduction: Advances in modern neonatology have improved survival of extremely premature and extremely low birth weight babies. Increased noise level is proven to be harmful to preterm babies and term ill babies in various ways. Determinants and baseline noise level should be assessed before necessary intervention. Objective: To assess the determinants of noise level at a level III neonatal intensive care unit (NICU) at the Castle Street Hospital for Women (CSHW), Sri Lanka. Method: A prospective observational study was done at NICU, CSHW, Sri Lanka. Data were collected using two NDI USB Digital sound level data loggers recorded noise level on a weighted decibel scale (dBA) every minute continuously for three weeks. Data was exported using provided software. Average noise level was analysed separately for consultant ward round (9am-12pm), nursing handing-over time (Daily 7-7.30am, 1-1.30pm and 7-7.30pm), admissions/emergencies (time taken from records) and a period supposed to be silence (Daily 1am-3am). Recommended standard ambient noise level for NICU by the American Academy of Paediatrics as well as Australasian Health Infrastructure Alliance is less than 45dB. Results: Average noise level recorded in NICU was 60 dBA which is considerably higher than recommended levels. During the consultant ward round the average noise level was 60.2 dBA. Noise levels at the morning, afternoon and evening handing-over times were 62.9, 62.7 and 60.9 dBA respectively. Noise level at supposed silent period (Daily 1am-3am) was 56.8 dBA. During admissions or emergencies which required ventilation (CPAP/conventional), the average noise level was as high as 65.8 dBA. Conclusions: Noise levels recorded in the NICU at the CSHW, Sri Lanka in all circumstances were higher than the recommended noise levels. Main contributions were machine alarms and conversations. Sri Lanka Journal of Child Health, 2019; 48(4): 312-315

Effectiveness of a visual noise warning system on noise levels in a surgical ICU: A quality improvement programme.

The effects of noise are harmful to patients in the ICU environment, and the latter are particularly noisy places. High noise levels seem to be a factor in sleep disturbance, which can, in turn, result in increased morbidity. High noise levels are a recognised problem in ICUs worldwide. The goal was to estimate the effect of a visual noise-warning system on noise levels in a surgical ICU before and after its implementation. A quality improvement initiative. A 12-bedded surgical ICU in a tertiary care university hospital. A total of 148 adult nonintubated and nonsedated patients completed the study, during a 6-week period. Noise levels were continuously recorded using a Type II sound level meter for 6 weeks. The study was divided into three phases. The first 2 weeks, baseline noise levels were measured (phase I). In week 3 of the study, a visual noise warning system (SoundEar II) that changed colour depending on noise levels within the ICU was installed and implemented (phase II). The alarm system was set to light up green at levels below 55 dBA, orange at levels between 55 and 60 dBA and red at levels above 60 dBA. The device was switched off at the beginning of week 5 and the sound level meter continued recording noise levels for another 2 weeks (phase III). Mean night-time noise level was 55.98 dBA in the preintervention phase, 54.14 dB during the intervention, and 54.98 dBA in the postintervention phase. Mean noise level was reduced statistically significantly by 1.35 dBA, and there was a sustained reduction of 0.86 dBA from the baseline noise level 2 weeks after SoundEar II was switched off. Visual noise warning systems can be effective in achieving a reduction in noise levels in critical care units.

Underwater Acoustic Impulsive Noise Monitoring in Port Facilities: Case Study of the Port of Cartagena.

Recording underwater impulsive noise data is an important aspect of mitigating its environmental impact and improving maritime environmental management systems. This paper describes the method used and results of the spatial monitoring of both the baseline noise level and the impulsive noise sources in the Port of Cartagena. An autonomous vessel was equipped with a smart digital hydrophone with a working frequency range between 10 and 200 kHz and a received voltage response (RVR) of, approximately, −170 dB re 1V/µPa. A GIS map was drawn up with the spatiotemporal distribution of the basal sound pressure levels by coupling the acoustic data with the vessel’s GPS positions to identify the sources of the impulsive noise of interest and their temporal characteristics. The loading of cargo containers was identified as the main source of impulse noise. This study is the first of a series designed to obtain accurate information on underwater noise pollution and its potential impact on biodiversity in the Port of Cartagena.