The Effects of Hospital Noise Pollution and Noise Sensitivity on Patient`s Acoustic Comfort, Noise Annoyance, and Intention to Leave

1. Introduction

Hospitals are intended to serve as healing environments, yet they are often characterized by excessive levels of environmental noise that can contradict their therapeutic purpose. Sources of hospital noise are numerous and varied, ranging from medical equipment, ventilation systems, and staff activities, to patient movement and visitor interactions.^1,2 In high-density hospital settings, noise levels frequently exceed internationally recommended thresholds, potentially interfering with both patient recovery and staff performance.³ The World Health Organization suggests that noise levels in hospital wards should not exceed 35 dB during the day and 30 dB at night. However, many studies have shown that these levels are consistently surpassed, often reaching peaks above 85 dB.^4,5

Excessive noise in healthcare facilities is more than a simple environmental nuisance—it can have complex consequences on physiological, psychological, and behavioral health. Research has demonstrated associations between prolonged exposure to noise and hearing impairments, risk of cancer, elevated heart rates, blood pressure irregularities, increased cortisol levels, and sleep disturbances in patients.^6–8 On a psychological level, noise contributes to anxiety, reduced performance, stress, and emotional distress, complicating recovery trajectories.^9–11 For healthcare providers, the effects are similarly detrimental, leading to higher levels of occupational burnout, fatigue, and even intention to resign.^12,13 Such outcomes underline the imperative need to understand and mitigate the impact of hospital noise exposure.

Among patients, individual differences in noise sensitivity may moderate their responses to environmental soundscapes. Noise sensitivity is a stable personality trait that reflects how strongly a person reacts to noise, independent of the objective sound intensity.¹⁰ Highly noise-sensitive individuals are more likely to experience discomfort and perceive sound as more disturbing than others, which may amplify their annoyance and overall dissatisfaction with the hospital experience.¹⁴ In clinical settings, noise-sensitive patients might display lower pain thresholds, poorer sleep quality, and greater susceptibility to noise-induced stress.

One critical dimension in understanding patients’ reactions to noise is acoustic comfort—a concept referring to the subjective perception of the acoustic environment as pleasant, tolerable, and non-disruptive. While often discussed in architectural and environmental psychology literature, acoustic comfort has recently attracted attention in hospital research due to its connection to patient satisfaction and healing outcomes.¹⁵ Factors influencing acoustic comfort include background noise levels, variability, predictability, and the perceived control over the auditory environment.⁶ Poor acoustic comfort can lead to reduced trust in medical care, increased anxiety, and decreased willingness to remain in the facility.

Relatedly, noise annoyance—defined as a subjective negative reaction to noise—is one of the most reported emotional responses among hospitalized individuals. Annoyance can arise from both the intensity and the meaning attributed to noise, with many patients perceiving certain sounds (e.g., alarms, staff conversations) as intrusive or inappropriate in a care context.¹ Chronic annoyance is not merely an emotional state but has been linked to increased health risks and behavioral outcomes, such as reduced adherence to treatment, complaints, and negative evaluations of care.⁹

Perhaps one of the most understudied yet consequential behavioral outcomes in hospital noise research is intention to leave, which refers to the patient’s conscious consideration or decision to discharge prematurely due to discomfort or dissatisfaction. While extensively studied among healthcare staff in relation to burnout and workplace environment,¹² little is known about how environmental noise might affect patients’ intentions to leave. This is particularly relevant given that early discharge—if not medically indicated—can negatively affect health outcomes and impose further burdens on healthcare systems. Despite increasing awareness of the acoustic challenges in hospitals, many studies have either focused solely on staff-related outcomes or have examined noise as an isolated environmental factor without accounting for individual differences in noise sensitivity.^16,17 Additionally, limited empirical work has explored the simultaneous effects of hospital noise pollution and noise sensitivity on multiple patient-centered outcomes, including acoustic comfort, noise annoyance, and behavioral intentions. Addressing these gaps requires a multidimensional understanding of how hospital noise interacts with psychological traits to shape patients’ experiences. Integrating environmental, psychological, and behavioral domains offers a more holistic framework for assessing acoustic health in clinical settings. This perspective is especially crucial in inpatient wards where patients often have limited control over their environment and may be particularly vulnerable due to illness, stress, or restricted mobility.⁵

Despite growing international awareness of hospital noise pollution, many low- and middle-income countries—including Iran—often rely on generalized international guidelines such as those from the WHO or EPA, while lacking detailed, enforceable national standards specifically tailored for their healthcare settings. Consequently, there is limited region-specific data available to inform noise reduction policies and patient-centered acoustic design in these contexts. Therefore, the current investigation was designed to examine the complex relationships among hospital noise pollution, noise sensitivity, and key patient outcomes including acoustic comfort, noise annoyance, and intention to leave. By adopting a comprehensive perspective that considers both environmental exposures and individual psychological dispositions, this study aims to contribute to the growing body of evidence supporting the need for acoustically mindful hospital design and policy.

2. Methodology

3. Results

The demographic profile of the study sample included a total of 226 hospitalized patients, with an almost equal gender distribution (49.6% male and 50.4% female). A large proportion of the participants were married (73.0%), while 27.0% were single. In terms of hospitalization units, nearly half of the patients were admitted to internal medicine wards (42.2%), followed by general surgery (37.2%) and the coronary care unit (CCU) (18.6%). These results indicate that the sample reflects a diverse clinical population across both medical and surgical departments (see Table 1).

The mean ± SD of the dimensions of abovementioned variables is presented in Table 2.

The dependencies among the marginal probabilities of the studied variables based on the Bayesian network model is shown in the Figure 1.

Figure 1. The dependencies among the marginal probabilities of the studied variables based on the Bayesian network model.

Table 3 illustrates the marginal probability distribution, derived from the Conditional Probability Tables (CPT), for the examined variables. The CPTs quantify the associations among the variables.

Model updating was performed by instantiating the target node as evidence, leading to a revision of all variable probability distributions within the Bayesian Network. The updated probabilities are detailed in Table 4.

Under conditions of high Level L_den, the probability of high annoyance, low acoustic comfort and intention to leave variables increased by 12.4%, 6.3% and 5%, respectively. In contrast, the probabilities of low annoyance, low intention to leave and high acoustic comfort decreased by 9.4%, 7.4% and 5.1% (Figure 2).

Figure 2. Sensitivity analysis on high L_den.

Under conditions of high-Level Sensitivity, the probability of high annoyance, low acoustic comfort and high intention to leave variables increased by 9.1%, 6.2 and 4.7 %, respectively. In contrast, the probabilities of low annoyance, low intention to leave and high acoustic comfort decreased by 9.6%, 7.2% and 5.2% (Figure 3).

Figure 3. Sensitivity analysis on high sensitivity.

Among the variables under conditions of 100% High Level L_den and 100% Low Sensitivity, the changes were observed in: a 1.8% increase in high intention to leave, a 1.1% increase in moderate acoustic comfort and low annoyance, a 1.5% decrease in moderate intention to leave and a 1.3% decrease in low annoyance (Figure 4). It is notable that the extent of changes in this section is negligible.

Figure 4. Sensitivity analysis on high Lden and low sensitivity.

Concerning the variables under the stipulated conditions of 100% Low Level L_den and 100% High sensitivity, the most prominent augmentations were evidenced in moderate annoyance, high intention to leave and moderate acoustic comfort, quantified at 3.7%, 1.5%, and 1.1%, respectively. Conversely, diminutions of 3.9%, 3%, and 1.5% were observed in the values of high annoyance, low acoustic comfort and moderate intention to leave (Figure 5).

Figure 5. Sensitivity analysis on low L_den and high sensitivity.

Under conditions of 100% High Level L_den and Sensitivity, analysis of change variables revealed that the most substantial positive variations occurred in high annoyance, low acoustic comfort and high intention to leave, with increases of 26.1%, 13.1% and 10.6%. Conversely, a corresponding analysis indicated decreases of 19.6%, 14.3% and 10.5% in low annoyance and intention to leave (Figure 6).

Figure 6. Sensitivity analysis on high L_den and sensitivity.

The sensitivity analysis of the studied variables is reported in Table 5, with a positive sign indicating an increase and a negative sign indicating a decrease.

4. Discussion

The present study elucidates the complex interplay between hospital noise pollution, noise sensitivity, and critical patient outcomes, including acoustic comfort, noise annoyance, and intention to leave. Our findings reveal several noteworthy patterns that both corroborate and extend existing literature in healthcare acoustics. The observed mean L_den level of 57.95 dB (±6.61) substantially exceeds WHO recommendations (35 dB daytime/30 dB nighttime), mirroring findings from recent global studies. For instance, Nyembwe et al. (2023) documented comparable noise levels (55–72 dB) in ICUs across Congolese hospitals, while Amoatey et al. (2022) reported 24-hour averages of 63.5 dB in Omani healthcare facilities.^4,5 This persistent non-compliance with international standards across diverse healthcare systems suggests a systemic failure in noise control implementation that transcends geographical boundaries.

Bayesian Network analysis demonstrated that high noise sensitivity amplified the negative effects of noise exposure, increasing the probability of high noise annoyance by 26.1% when both factors were present. This finding aligns with emerging neurophysiological evidence from Zhou et al. (2020), whose fMRI studies revealed heightened amygdala activation in noise-sensitive individuals exposed to hospital sounds.⁶ The moderated mediation pattern observed provides empirical support for the Stressor-Sensitivity Model proposed by Gong et al. (2022), which posits that individual differences in sensory processing modulate environmental stress responses.⁹ Noise annoyance has long been recognized as one of the primary effects of noise exposure across various environments. It is also closely correlated with individual noise sensitivity. In other words, noise annoyance is influenced by two sets of variables: noise exposure, which acts as an external factor, and noise sensitivity, which is an individual-specific characteristic. The results of the present study indicate that both of these factors contribute to increased annoyance among patients. Moreover, when both variables were set at their highest levels in the model, they demonstrated a synergistic effect, leading to a significantly greater increase in perceived annoyance. The literature has shown that noise annoyance acts as a mediator of the various health and psychological outcomes of noise exposure.³¹ Numerous studies have indicated that individuals who are highly sensitive to noise experience greater annoyance when exposed to environmental noise, which in turn is associated with more adverse health outcomes. In this study, it was found that noise annoyance increased under all conditions — whether due to high noise exposure or heightened individual sensitivity to noise. This increase in annoyance was accompanied by a corresponding rise in the intention to leave the hospital. Thus, both noise exposure and noise sensitivity influence the intention to leave the hospital through two pathways: a direct effect and an indirect effect mediated by noise annoyance. In all cases, increases in either noise levels or sensitivity led to higher intentions to leave hospital. It has been reported that annoying stimuli such as noise, can increase individual arousal and provide a motivating reason to leave the environment.³² Therefore, it can be concluded that in hospital settings, noise annoyance may lead patients to decide to leave the facility prematurely, before completing their prescribed course of hospitalization.

Acoustic comfort is a subjective evaluation of the sound environment, influenced by both external acoustic stimuli and individual psychological predispositions such as noise sensitivity. Patients with heightened noise sensitivity tend to appraise hospital soundscapes more negatively, reporting lower levels of acoustic comfort even under moderate noise conditions.⁶ This discomfort may stem from sensory overload, heightened vigilance, or perceived loss of control over the environment. In the present study, patients with high noise sensitivity demonstrated a pronounced decrease in acoustic comfort, particularly when ambient noise levels were also elevated. Reduced acoustic comfort, in turn, was associated with an increased intention to leave the hospital. This relationship may be explained by the role of comfort as a mediating factor in environmental satisfaction and perceived stress. Studies suggest that when patients feel aurally overwhelmed, their sense of well-being declines, leading to emotional fatigue and decreased willingness to remain in the hospital.⁹ Thus, noise sensitivity and environmental exposure jointly reduce acoustic comfort, which may act as an intermediate pathway contributing to the decision to leave the care environment prematurely. Beyond its effects on comfort and annoyance, the interaction between noise exposure and individual sensitivity may directly influence patients’ behavioral responses, including the decision to leave the hospital early. In our model, high L_den and elevated noise sensitivity increased the probability of moderate and high intention to leave by more than 3.7% and 10.6%, respectively. This behavior may be driven by psychological mechanisms such as avoidance coping or perceived threat, wherein patients interpret persistent noise as a signal of low-quality care or lack of control. Premature hospital discharge has been associated with adverse outcomes, including incomplete treatment, higher readmission rates, and reduced patient satisfaction.¹⁴ While such departures are typically multifactorial, environmental discomfort—particularly in the form of uncontrolled noise—may act as a powerful yet under-recognized contributor. Therefore, mitigating hospital noise and addressing the needs of noise-sensitive individuals is not only a matter of comfort, but also a determinant of patient retention and treatment adherence.

According to the results presented in Table 5, noise annoyance exhibits greater variability compared to acoustic comfort, primarily due to fluctuations in both noise sensitivity and exposure levels. This finding highlights the significance of noise annoyance as a key factor within hospital environments. Numerous studies have demonstrated that noise annoyance has a substantial impact on various aspects of health, including the elevation of stress hormone levels.⁹ Furthermore, it can contribute to increased anxiety and depressive symptoms in individuals.^9,33 Considering that patients are often already in a compromised state of health, noise annoyance may exacerbate their medical conditions by heightening stress, anxiety, and depression, potentially leading them to leave the hospital prematurely—before completing the prescribed treatment process. In summary, noise annoyance, as the most prominent consequence of noise exposure and heightened noise sensitivity, can give rise to a wide range of adverse health outcomes.³³

While this study provides valuable insights into the relationships between hospital noise pollution, individual noise sensitivity, and key patient outcomes, several limitations should be considered. First, the study was conducted in a single public hospital, which may limit the generalizability of the findings to other healthcare settings, particularly private institutions or those with different infrastructural and organizational characteristics. Second, the cross-sectional design restricts the ability to establish causal or temporal relationships between environmental noise exposure and patients’ psychological or behavioral responses. Third, although ward type was accounted for, other potentially influential clinical factors—such as pain levels, medication use, or individual health conditions—were not controlled and may have affected how noise was perceived. Moreover, the use of L_den as the sole noise metric, while practical and standardized, may have failed to capture more granular temporal fluctuations in noise exposure that could influence patient responses. Lastly, the reliance on self-reported measures introduces the possibility of response bias, despite the use of validated instruments, and underscores the importance of incorporating objective assessments in future research.

5. Conclusion

This study provides novel and compelling evidence on the intricate relationships between hospital noise pollution, individual noise sensitivity, and critical patient outcomes including acoustic comfort, noise annoyance, and intention to leave. The findings underscore the significant influence of both environmental (e.g., noise) and personal (e.g., noise sensitivity) variables on patients’ perceptual and behavioral responses within hospital settings. The results revealed that noise sensitivity acts as a key psychological synergist, amplifying the negative impact of noise on comfort, annoyance, and intention to leave. Moreover, annoyance and comfort acted as mediating factors in transmitting the negative effects of noise exposure and noise sensitivity on the intention to leave. Additionally, acoustic comfort emerged as a protective factor; improved acoustic comfort was associated with a reduced intention to leave, whereas increased noise annoyance had the opposite effect. In sum, hospital soundscapes are not merely ambient features—they are active components of the care environment that shape patient comfort, emotional states, and behavioral intentions. Addressing noise pollution, especially through targeted interventions for noise-sensitive individuals and improved acoustic design, should be viewed as an essential dimension of quality healthcare delivery.

Ethics approval and consent to participate

In accordance with the Declaration of Helsinki, ethical approval for this study was granted by the Medical Ethics Committee of Saveh University of Medical Sciences (Ethics Code: IR.SAVEHUMS.REC.1403.039). All procedures were conducted in full compliance with the approved ethical guidelines.