Voice use of nurses working in the intensive care unit during the COVID-19 pandemic.

OBJECTIVE: This study aimed to investigate the voice use of nurses working in intensive care units (ICUs) and their perception of acoustic environments. SETTING AND SAMPLE: The research was conducted in four different hospitals in China during the COVID-19 pandemic. A total of 60 ICU nurses were recruited for their voice use monitoring and 100 nurses participated in the survey. RESEARCH METHODOLOGY: Firstly, voice-related parameters such as voice level (SPL, dB), fundamental frequency (F0, Hz), and voicing time percentage (Dt, %) were measured using a vocal monitor. To collect data, a non-invasive accelerometer was attached to the participants' necks during their working hours. Secondly, the perception of the ICU acoustic environment was assessed using semantic differential. RESULTS: The results showed that nurses spoke approximately 0.9-4 dB louder to patients and colleagues in ICUs compared to quiet rooms, and their fundamental frequency (F0) significantly increased during work. The voice levels of nurses were influenced by background noise levels, with a significant correlation coefficient of 0.44 (p < 0.01). Furthermore, the background noise levels ranged from 58.1 to 73.9 dBA, exceeding the guideline values set by the World Health Organisation (WHO). The semantic differential analysis identified 'Stress' and 'Irritation' as the two main components, indicating the prevalence of negative experiences within ICUs. IMPLICATIONS FOR CLINICAL PRACTICE: This study highlights the potential risk of voice disorders among ICU nurses. The findings also underscore the importance of implementing strategies to reduce noise levels in ICUs to reduce voice disorders among nurses.

Smartphone applications for measuring noise in the intensive care unit: A feasibility study.

PURPOSE: This study aims to explore the suitability of using smartphone applications with low-cost external microphones in measuring noise levels in intensive care units. METHODS: Four apps and two external microphones were tested in a laboratory by generating test signals at five noise levels. The average noise levels were measured using the apps and a professional device (i.e. a sound level meter). A field test was performed in an intensive care unit with two apps and one microphone. Noise levels were measured in terms of average and maximum noise levels according to the World Health Organisation's guidance. All the measurements in both tests were conducted after acoustic calibration using a sound calibrator. RESULTS: Overall, apps with low-cost external microphones produced reliable results of averaged noise levels in both the laboratory and field settings. The differences between the apps and the sound level meter were within ±2 dB. In the field test, the best combination of app and microphone showed negligible difference (< 2 dB) compared to the sound level meter in terms of the average noise level. However, the maximum noise level measured by the apps exhibited significant differences from those measured by the sound level meter, ranging from -0.9 dB to -4.7 dB. CONCLUSION: Smartphone apps and low-cost external microphones can be used reliably to measure the average noise level in the intensive care unit after acoustic calibration. However, professional equipment is still necessary for accurate measurement of the maximum noise level.

Prevalence of voice handicap among nurses in intensive care units due to occupational noise during pandemic.

Background: Healthcare workers have been identified as being at risk of occupational voice disorders. Among them, nurses working in intensive care units (ICUs) are particularly vulnerable due to the risk factors that are associated with their exposure to high levels of noise. Thus, this study aimed to determine the prevalence of voice disorders among ICU nurses. Methods: A questionnaire was administered to 100 ICU nurses from four hospitals in China. The questionnaire assessed vocal-related symptoms, perceived voice handicap, frequently heard noise sources, and the quality of communications. Results: Results indicate that the most frequently reported voice symptoms were 'voice tiredness' and 'voiceless'. Nurses working more than 50 h per week experienced voice symptoms more frequently than nurses working for 40-50 h per week. The median value of the perceived voice handicap score (VHI-30) was 23, indicating mild voice handicap, while 24% of the nurses reported severe voice handicap. Longer working hours and working at patient wards were significantly associated with higher VHI-30 scores. The nurses also reported that the quality of verbal communication with patients and colleagues and voice problems worsened during the COVID-19 pandemic. Conclusion: More than 20% of nurses reported severe voice handicap, however, voice handicap among ICU nurses did not appear universally to all nurses. Further research is necessary to identify the risk factors associated with voice disorders and the mechanism behind such heterogeneity among ICU nurses.

Acoustic environments of intensive care units during the COVID-19 pandemic.

This study aims to investigate the typical noise levels and noise sources in an intensive care unit (ICU) during the COVID-19 pandemic. Acoustic experiments were conducted over 24 hrs in patient wards and at nurse stations in four Chinese hospitals. From the measurements, noise levels and sources were analysed in terms of the A-weighted equivalent sound pressure levels (L Aeq) and A-weighted maximum Fast time-weighted sound pressure levels (L AFmax) over three different time periods during the day (i.e. day, evening and night). Overall, noise levels (L Aeq) for 24 hrs in all hospitals exceeded the World Health Organisation's (WHO) guide levels, varying from 51.1 to 60.3 dBA. The highest maximum noise level reached 104.2 dBA. The single-bedded wards (side rooms) were quieter than multi-bedded wards, and night time noise levels were quieter than daytime and evening across all hospitals. It was observed that the most dominant noise sources were talking/voices, door-closing, footsteps, and general activities (e.g. noise from cleaning equipment and cutlery sound). Footsteps became an unexpected dominant noise source during the pandemic because of the staff's disposable shoe covers which made footsteps noisier. Patient alarms and coughing varied significantly between patients. Talking/voices produced the highest maximum median values of the sound exposure level (SEL) and the maximum noise level at all sites. Noise levels in all the patient rooms were more than the WHO guidelines. The pandemic control guidelines had little impact on the noise levels in the ICUs.

Attitudes towards outdoor and neighbour noise during the COVID-19 lockdown: A case study in London.

To stop the spread of COVID-19 transmission, the UK put a first lockdown on the entire country during the months of March and May 2020, which strictly curtailed personal mobility and economic activities. The present study is aimed to understand attitude of people towards noise inside their homes in London during the lockdown. Tweets from the social media platform were collected during the lockdown and the same periods in 2019. Additionally, subjective responses to outdoor and neighbour noises were collected through a questionnaire survey. Tweets about noise complaints during the lockdown were more than twice of those before introduction of lockdown. A substantial increase in talking/shouting, and TV/music activities were observed among the neighbour noise sources. Similar findings were obtained from the survey. The respondents answered that the perceived outdoor noise level decreased but perceived neighbour noise level increased during the lockdown. The outdoor noise annoyance ratings were revealed to be significantly lower than those before the lockdown. In contrast, neighbour noises were more frequently heard and annoyance ratings increased compared to the pre-lockdown period. In particular, talking/shouting and TV/music were most annoying. Furthermore, neighbour noise was more annoying than outdoor noise during the lockdown. This suggests that neighbour noise is more problematic than outdoor noise during lockdown. The findings of this study would be useful in designing the future strategy to enhance the acoustic comfort and city sustainability.

Attitudes to Noise Inside Dwellings in Three Megacities: Seoul, London, and São Paulo.

This study investigated people's attitudes towards noise inside their homes. Online questionnaire surveys were conducted in Seoul, London, and São Paulo. The questionnaire was designed to assess annoyance caused by noise from neighbours and environmental noise (transportation). Information was also collected on situational, personal, and socio-demographic variables. Respondents that were more annoyed by outdoor noise inside their dwelling reported higher neighbour noise annoyance. In Seoul, neighbour noise was found to be more annoying than outdoor noise, and those with higher noise sensitivity reported higher annoyance towards neighbour noise. However, neighbour noise and outdoor noise was found to be equally annoying in London and São Paulo. For neighbour noise, the average percentage of respondents hearing structure-borne sources compared to airborne sources differed in each city. Most neighbour noise sources in São Paulo gave rise to higher annoyance ratings than Seoul and London. Education and income levels had a limited effect on annoyance and coping strategy. Annoyance with indoor noise from neighbours was found to have stronger relationships with cognitive and behavioural coping strategies than outdoor noise annoyance.

Association between transportation noise and blood pressure in adults living in multi-storey residential buildings.

Epidemiological studies have demonstrated that transportation noise is associated with blood pressure and hypertension, but little is known about its relationship in the adults living in multi-storey residential buildings, where neighbour noise is frequently heard. This study aimed to investigate the effects of transportation noise exposure on blood pressure in 400 adult residents of multi-storey residential buildings and modifying effects of indoor noise annoyance and self-rated noise sensitivity on the associations between transportation noise and blood pressure. Noise levels were measured on the top of buildings for 24 h, and levels of each house unit were then predicted for different sources and periods using noise maps. Adjusted linear regression analyses were performed to estimate the associations of noise exposure levels (LDEN, LDay, and LNight) with systolic blood pressure (SBP) and diastolic blood pressure (DBP). The questionnaire also included questions related to annoyance caused by indoor noise, noise sensitivity, and sociodemographic variables. Adjusted regression models yielded significant effect estimates for a 5-dBA increase in overall transportation noise for 24 h (SBP ß = 0.20; 95% confidence interval (CI): 0.25-1.81; DBP ß = 0.16; 95% CI: 0.12-0.93). The overall (road traffic and railway noise) and road traffic noises showed stronger associations with the SBP than with the DBP, while the railway noise had similar associations with the SBP and the DBP. Stronger associations were estimated for the participants who reported higher indoor noise annoyance ratings. Furthermore, the regression coefficients between the noise exposure and blood pressure slightly increased (ß = 0.26 and 0.22 for overall and road traffic noise, respectively for SBP) in a subgroup that excluded participants exposed to high railway noise. The results lend some support to the hypothesis that long-term exposure to transportation noise is associated with a higher blood pressure in adults living in multi-storey residential buildings.

How residents in multifamily housing cope with neighbour noise: The role of attitude towards the neighbours.

AIMS: Residents in multifamily housing are considerably exposed to neighbour noise, which can lead to neighbour disputes and even criminal violence. This study investigated how residents' attitudes towards noisy neighbours develop and the role of such attitudes in their reactions to neighbour noise. METHODS: In-depth interviews were carried out with 57 South Korean residents. The data were collected and analyzed using grounded theory methods. Concepts and categories were identified through open coding and axial coding, respectively. RESULTS: Residents' attitudes towards the neighbours (i.e., noise source) were grouped into friends, enemies, and strangers/acquaintances. Each attitude formation was influenced by the individual's past experience/history, the attitude shown by the neighbours, and the predictability/certainty of noise exposure. Different attitudes towards the neighbours resulted in different cognitive and behavioural copings. CONCLUSION: Given that the neighbour noise issue involves the interpersonal relationship between neighbours, the findings extend the scope of existing understanding. The paper suggests that further investigation into coping strategies would have practical implementations for reducing conflict arising from neighbour disputes.

Emotions evoked by exposure to footstep noise in residential buildings.

In the present study, the effect of footstep noise on emotions was investigated. This study used noise stimulus of human footsteps throughout the study. First, Korean emotion lexicons were collected from narratives of residents living in multi-family housing buildings. The lexicons were then classified into four emotion clusters, with three expressing negative emotions (anger, dislike, and pain) and the fourth depicting empathy. Since self-reported annoyance has long been investigated as one of the major non-auditory responses to noise, annoyance was measured along with affective responses in a laboratory experiment with varying noise levels. The findings revealed that the emotion and noise annoyance experienced by the participants were significantly affected by noise levels. All clusters expressing negative emotions showed strong correlations with noise annoyance, whereas that representing empathy showed the weakest correlation. Noise sensitivity and attitudes to the noise source were observed as possible moderators in emotional responses and annoyance ratings.

Relationships between non-acoustic factors and subjective reactions to floor impact noise in apartment buildings.

The aim of this study was to provide an understanding of how residents in apartment buildings perceive and react to impact sounds coming from the upstairs neighbours' dwellings. Based on existing theoretical and empirical studies on environmental noise, a conceptual model was developed to explain relationships among noise annoyance and non-acoustic factors. The model was then tested using structural equation modelling with survey data from residents living in apartment buildings (N = 487). The findings showed that the conceptual model was consistent with other models developed for environmental noises. The results indicated that annoyance induced by floor impact noise was associated with perceived disturbance, coping, and self-reported health complaints. Noise sensitivity had a direct impact on perceived disturbance and an indirect impact on annoyance, and moderating variables affected the non-acoustic factors. Exposure to footstep noises increased the impact size of noise sensitivity to disturbance. Predictability, marital status, and house ownership were found to influence the relationship between attitudes towards authorities and coping. In addition, a negative attitude towards neighbours (i.e., the noise source) moderated the positive relationship between annoyance and coping.

Impact of noise on self-rated job satisfaction and health in open-plan offices: a structural equation modelling approach.

This study uses a structural equation model to examine the effects of noise on self-rated job satisfaction and health in open-plan offices. A total of 334 employees from six open-plan offices in China and Korea completed a questionnaire survey. The questionnaire included questions assessing noise disturbances and speech privacy, as well as job satisfaction and health. The results indicated that noise disturbance affected self-rated health. Contrary to popular expectation, the relationship between noise disturbance and job satisfaction was not significant. Rather, job satisfaction and satisfaction with the environment were negatively correlated with lack of speech privacy. Speech privacy was found to be affected by noise sensitivity, and longer noise exposure led to decreased job satisfaction. There was also evidence that speech privacy was a stronger predictor of satisfaction with environment and job satisfaction for participants with high noise sensitivity. In addition, fit models for employees from China and Korea showed slight differences. PRACTITIONER SUMMARY: This study is motivated by strong evidence that noise is the key source of complaints in open-plan offices. Survey results indicate that self-rated job satisfaction of workers in open-plan offices was negatively affected by lack of speech privacy and duration of disturbing noise.

Assessment of rural soundscapes with high-speed train noise.

In the present study, rural soundscapes with high-speed train noise were assessed through laboratory experiments. A total of ten sites with varying landscape metrics were chosen for audio-visual recording. The acoustical characteristics of the high-speed train noise were analyzed using various noise level indices. Landscape metrics such as the percentage of natural features (NF) and Shannon's diversity index (SHDI) were adopted to evaluate the landscape features of the ten sites. Laboratory experiments were then performed with 20 well-trained listeners to investigate the perception of high-speed train noise in rural areas. The experiments consisted of three parts: 1) visual-only condition, 2) audio-only condition, and 3) combined audio-visual condition. The results showed that subjects' preference for visual images was significantly related to NF, the number of land types, and the A-weighted equivalent sound pressure level (LAeq). In addition, the visual images significantly influenced the noise annoyance, and LAeq and NF were the dominant factors affecting the annoyance from high-speed train noise in the combined audio-visual condition. In addition, Zwicker's loudness (N) was highly correlated with the annoyance from high-speed train noise in both the audio-only and audio-visual conditions.

Relating traffic, construction, and ventilation noise to cognitive performances and subjective perceptions.

The present study investigates the cognitive performance and subjective perceptions in the context of road traffic noise alone and multiple noises, including construction and ventilation noises. A total of 20 university students were exposed to seven noise conditions. Laboratory experiments employed semantic and episodic memory tasks. Self-reports of perception were collected from the participants. It was found that multiple noise sources impaired the free recall of words, and free recall scores were affected by noise type. Significant differences in free recall scores were found when the noise level difference between the individual noise and multiple noise sources was more than 5 dB. In contrast, word comprehension did not mediate the effects of noise on semantic memory. Annoyance caused by multiple noise sources correlated highly with the results of the free recall and word comprehension tasks. Moreover, loudness and roughness were found to account for the annoyance ratings of combinations of road traffic noise with construction or ventilation noises.

Soundwalk approach to identify urban soundscapes individually.

This study proposes a soundwalk procedure for evaluating urban soundscapes. Previous studies, which adopted soundwalk methodologies for investigating participants' responses to visual and acoustic environments, were analyzed considering type, evaluation position, measurement, and subjective assessment. An individual soundwalk procedure was then developed based on asking individual subjects to walk and select evaluation positions where they perceived any positive or negative characteristics of the urban soundscape. A case study was performed in urban spaces and the results were compared with those of the group soundwalk to validate the individual soundwalk procedure. Thirty subjects (15 architects and 15 acousticians) participated in the soundwalk. During the soundwalk, the subjects selected a total of 196 positions, and those were classified into 4 groups. It was found that soundscape perceptions were dominated by acoustic comfort, visual images, and openness. It was also revealed that perceived elements of the acoustic environment and visual image differed across classified soundscape groups, and there was a difference between architects and acousticians in terms of how they described their impressions of the soundscape elements. The results show that the individual soundwalk procedure has advantages for measuring diverse subjective responses and for obtaining the perceived elements of the urban soundscape.

Combined effect of noise and vibration produced by high-speed trains on annoyance in buildings.

The effects of noise and vibration on annoyance in buildings during the passage of a nearby high-speed train have been investigated in a laboratory experiment with recorded train noise and 20 Hz vibration. The noises included the effects of two types of façade: windows-open and windows-closed. Subjects were exposed to six levels of noise and six magnitudes of vibration, and asked to rate annoyance using an 11-point numerical scale. The experiment consisted of four sessions: (1) evaluation of noise annoyance in the absence of vibration, (2) evaluation of total annoyance from simultaneous noise and vibration, (3) evaluation of noise annoyance in the presence of vibration, and (4) evaluation of vibration annoyance in the absence of noise. The results show that vibration did not influence ratings of noise annoyance, but that total annoyance caused by combined noise and vibration was considerably greater than the annoyance caused by noise alone. The noise annoyance and the total annoyance caused by combined noise and vibration were associated with subject self-ratings of noise sensitivity. Two classical models of total annoyance due to combined noise sources (maximum of the single source annoyance or the integration of individual annoyance ratings) provided useful predictions of the total annoyance caused by simultaneous noise and vibration.

Acoustical characteristics of water sounds for soundscape enhancement in urban open spaces.

The goal of the present study is to characterize water sounds that can be used in urban open spaces to mask road traffic noise. Sounds and visual images of a number of water features located in urban open places were obtained and subsequently analyzed in terms of psychoacoustical metrics and acoustical measures. Laboratory experiments were then conducted to investigate which water sound is appropriate for masking urban noise. The experiments consisted of two sessions: (1) Audio-only condition and (2) combined audio-visual condition. Subjective responses to stimuli were rated through the use of preference scores and 15 adjectives. The results of the experiments revealed that preference scores for the urban soundscape were affected by the acoustical characteristics of water sounds and visual images of water features; Sharpness that was used to explain the spectral envelopes of water sounds was proved to be a dominant factor for urban soundscape perception; and preferences regarding the urban soundscape were significantly related to adjectives describing "freshness" and "calmness."

Evaluation of speech transmission in open public spaces affected by combined noises.

In the present study, the effects of interference from combined noises on speech transmission were investigated in a simulated open public space. Sound fields for dominant noises were predicted using a typical urban square model surrounded by buildings. Then road traffic noise and two types of construction noises, corresponding to stationary and impulsive noises, were selected as background noises. Listening tests were performed on a group of adults, and the quality of speech transmission was evaluated using listening difficulty as well as intelligibility scores. During the listening tests, two factors that affect speech transmission performance were considered: (1) temporal characteristics of construction noise (stationary or impulsive) and (2) the levels of the construction and road traffic noises. The results indicated that word intelligibility scores and listening difficulty ratings were affected by the temporal characteristics of construction noise due to fluctuations in the background noise level. It was also observed that listening difficulty is unable to describe the speech transmission in noisy open public spaces showing larger variation than did word intelligibility scores.

Non-auditory factors affecting urban soundscape evaluation.

The aim of this study is to characterize urban spaces, which combine landscape, acoustics, and lighting, and to investigate people's perceptions of urban soundscapes through quantitative and qualitative analyses. A general questionnaire survey and soundwalk were performed to investigate soundscape perception in urban spaces. Non-auditory factors (visual image, day lighting, and olfactory perceptions), as well as acoustic comfort, were selected as the main contexts that affect soundscape perception, and context preferences and overall impressions were evaluated using an 11-point numerical scale. For qualitative analysis, a semantic differential test was performed in the form of a social survey, and subjects were also asked to describe their impressions during a soundwalk. The results showed that urban soundscapes can be characterized by soundmarks, and soundscape perceptions are dominated by acoustic comfort, visual images, and day lighting, whereas reverberance in urban spaces does not yield consistent preference judgments. It is posited that the subjective evaluation of reverberance can be replaced by physical measurements. The categories extracted from the qualitative analysis revealed that spatial impressions such as openness and density emerged as some of the contexts of soundscape perception.

Perceptual assessment of quality of urban soundscapes with combined noise sources and water sounds.

In this study, urban soundscapes containing combined noise sources were evaluated through field surveys and laboratory experiments. The effect of water sounds on masking urban noises was then examined in order to enhance the soundscape perception. Field surveys in 16 urban spaces were conducted through soundwalking to evaluate the annoyance of combined noise sources. Synthesis curves were derived for the relationships between noise levels and the percentage of highly annoyed (%HA) and the percentage of annoyed (%A) for the combined noise sources. Qualitative analysis was also made using semantic scales for evaluating the quality of the soundscape, and it was shown that the perception of acoustic comfort and loudness was strongly related to the annoyance. A laboratory auditory experiment was then conducted in order to quantify the total annoyance caused by road traffic noise and four types of construction noise. It was shown that the annoyance ratings were related to the types of construction noise in combination with road traffic noise and the level of the road traffic noise. Finally, water sounds were determined to be the best sounds to use for enhancing the urban soundscape. The level of the water sounds should be similar to or not less than 3 dB below the level of the urban noises.