Background: Exposure to acute noise can cause an increase in biological stress reactions, which provides biological plausibility for a potential association between sustained noise exposure and stress-related health effects. However, the certainty in the evidence for an association between exposures to noise on short- and long-term biomarkers of stress has not been widely explored. The objective of this review was to evaluate the strength of evidence between noise exposure and changes in the biological parameters known to contribute to the development of stress-related adverse cardiovascular responses. Materials and Methods: This systematic review comprises English language comparative studies available in PubMed, Cochrane Central, EMBASE, and CINAHL databases from January 1, 1980 to December 29, 2021. Where possible, random-effects meta-analyses were used to examine the effect of noise exposure from various sources on stress-related cardiovascular biomarkers. The risk of bias of individual studies was assessed using the risk of bias of nonrandomized studies of exposures instrument. The certainty of the body of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Results: The search identified 133 primary studies reporting on blood pressure, hypertension, heart rate, cardiac arrhythmia, vascular resistance, and cardiac output. Meta-analyses of blood pressure, hypertension, and heart rate suggested there may be signals of increased risk in response to a higher noise threshold or incrementally higher levels of noise. Across all outcomes, the certainty of the evidence was very low due to concerns with the risk of bias, inconsistency across exposure sources, populations, and studies and imprecision in the estimates of effects. Conclusions: This review identifies that exposure to higher levels of noise may increase the risk of some short- and long-term cardiovascular events; however, the certainty of the evidence was very low. This likely represents the inability to compare across the totality of the evidence for each outcome, underscoring the value of continued research in this area. Findings from this review may be used to inform policies of noise reduction or mitigation interventions.

Background Noise in intensive care units (ICUs) has always been a problem, but noise above the recommended range affects not only the patient but staff as well. It is clear that some noise in the ICU is inevitable, but exceeding the normal range brings various physiologic and psychologic changes, which directly affect health. This review presents a synthesis of noise sources in the ICU and the potential interventions designed to attenuate noise and protect patients. Materials and Methods An extensive literature search, using electronic databases such as MEDLINE, PubMed, Google Scholar, and Research gate to understand the noise in ICU, effects of noise, and noise reduction interventions were undertaken. Results Findings were such as noise enhances the release of cortisol, increases oxygen consumption, increases sleep disturbances, increases the need for analgesia and sedation, and disrupts circadian rhythm. Many studies reported that measurement was always higher despite implementing noise reduction interventions. Conclusions ICU survivors always recall their memories, and for them, ICU admission becomes a negative experience for life. However, the sustainability of any single intervention did not show awe-inspiring results, whereas a bundle kind of interventions did show some effects. However, high-quality evidence demonstrating the benefit of any intervention on patient outcomes is still lacking.

Background: Exposure to noise can increase biological stress reactions and that could increase the risk of stress-related prenatal effects, including adverse obstetric outcomes; however, the association between exposure to noise and adverse obstetric outcomes has not been extensively explored. The objective of this review was to evaluate the evidence between noise exposures and adverse obstetric outcomes, specifically preeclampsia, gestational diabetes, and gestational hypertension. Materials and Methods: A systematic review of English language, comparative studies available in PubMed, Cochrane Central, EMBASE, and CINAHL databases between January 1, 1980 and December 29, 2021 was performed. Risk of bias for individual studies was assessed using the Risk of Bias Instrument for Nonrandomized Studies of Exposures, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the certainty of the body of evidence for each outcome. Results: Six studies reporting on preeclampsia, gestational diabetes, and gestational hypertension were identified. Although some studies suggested there may be signals of increased responses to increased noise exposure for preeclampsia and gestational hypertension, the certainty in the evidence of an effect of increased noise on all the outcomes was very low due to concerns with risk of bias, inconsistency across studies, and imprecision in the effect estimates. Conclusions: While the certainty of the evidence for noise exposure and adverse obstetric outcomes was very low, the findings from this review may be useful for directing further research in this area, as there is currently limited evidence available. These findings may also be useful for informing guidelines and policies involving noise exposure situations or environments.

Background Leisure noise may have a significant impact on hearing thresholds and young adults are often exposed to loud music during leisure activities. This behavior puts them at risk of developing noise-induced hearing loss (NIHL). A frequent initial indication of NIHL is reduced hearing acuity at 4 kHz. The objective of the current study was to assess the role of the medial olivocochlear reflex (MOCR) in leisure noise-exposed individuals with and without a 4-kHz notch. Materials and Methods Audiological evaluation, including pure-tone and immittance audiometry, was performed for 156 college-going, young adults between May 2019 to December 2019. All participants had averaged pure-tone audiometric thresholds within normal limits, bilaterally. Annual individual exposure to personal listening devices (PLDs) was calculated using the Noise Exposure Questionnaire. The participants were then categorized into exposed (with and without audiometric 4 kHz notch) and nonexposed groups. Transient-evoked otoacoustic emission amplitude and its contralateral suppression were measured using linear and nonlinear click stimuli to study the effect of leisure noise exposure on MOCR. Results A significantly reduced overall contralateral suppression effect in participants exposed to PLD usage (P = 0.01) in both linear and nonlinear modes. On the contrary, significantly increased suppression was observed in linear mode for the 4 kHz frequency band in the PLD-exposed group without an audiometric notch (P = 0.009), possibly suggesting an early biomarker of NIHL. Conclusion Measuring contralateral suppression of otoacoustic emissions may be an effective tool to detect early NIHL in leisure noise-exposed individuals.

Context: Despite the fact that the new generations of rotary tools emit less noise, some recent studies suggest that dental students are still at risk of hearing impairment. Aims: The aim of the study was to determine a possible association between noise exposure from dental equipment and early signs of noise-induced hearing loss (NIHL) in dental students. Settings and Design: A cross-sectional study was carried out with dental and non-dental students from two universities in Chile. Methods and Material: A group of 102 dental students routinely exposed to noise emitted from dental equipment was selected as the study group. A group of 251 non-dental students was selected as the control group. Pure-tone audiometry was carried out on all participants ensuring that they were not exposed to noise for at least 24 hours prior to testing. The presence of a notch was determined for each participant. Statistical analysis used: Simultaneous-quantile regressions were used to compare percentiles of the hearing threshold between both groups. Then, the notch prevalence ratio adjusted by gender and age was estimated for each group of participants. Finally, the prevalence of an audiometric notch was compared between both groups using logistic regression models and generalized linear methods. Both fixed effect and multilevel hierarchy models were constructed. Results: Significant differences between groups for the 75th percentile of hearing threshold distributions at 4 and 6 kHz in the left ear and at 6 kHz in the right ear were found. In addition, study group participants exhibited a significantly higher prevalence of a notch at 4 kHz in the left ear than control group participants. Conclusions: Exposure to noise derived from learning activities as a dental student is associated with early signs of NIHL. Such signs include poorer hearing thresholds than those of non-dental students at 4 and 6 kHz as well as the presence of a notch at high frequencies.

Background: Noise sensitivity moderates the association between environmental noise exposure and annoyance and health outcomes. Methods: In normally hearing adults, we measured noise sensitivity in three ways: using the noise sensitivity questionnaire, a 3-point self-rating, and the loudness discomfort level (LDL; mean reported discomfort level for tone bursts). We then presented recordings of a 15-second 80 dBLAeq aeroplane overflight and participants rated the annoyance and loudness they experienced. Results: The three measures of noise sensitivity were not well correlated with each other, and only the overall LDL was associated with the ratings of loudness and annoyance in response to the aeroplane sounds. Conclusions: This implies that our current measures of noise sensitivity may only capture parts of the underlying construct, and therefore underestimate effects due to it on the association between environmental noise and annoyance and health outcomes. We developed a theoretical model to describe the set of factors that may influence a person’s sensitivity to noise and propose that interaction between the systems described is the basis for noise sensitivity. This paradigm alters the focus of noise research from the annoyance caused by the sound, to the sensitization to noise that may occur as a result of the interplay of many factors. We hope that our model will allow research to explore the sensitizing factors for noise more easily and systematically.

Objective: To study the Influence of Auditory Training on acceptable noise level (ANL) scores in elderly persons with hearing impairment. Design: Quasi-experimental study design. Study sample: A total of 20 bilateral mild to moderately severe sensorineural hearing loss participants with “high” ANL scores were taken into the study and randomly allocated to experimental and control groups. In the time frame, the experimental group provided 12 sessions of speech in noise training with a hearing aid and the baseline measures were repeated in both groups. Results: The Acceptable noise level and Speech in Noise scores significantly improved post-training only in the experimental group. They also showed a significant difference “Client Oriented Scale of Improvement (COSI)” scale in the domain “Conversation in Noise”. Conclusions: Acceptable noise level is susceptible to training similar to that of speech in noise score. It provides hope to the individuals who are poor candidates to the hearing aids.

Objective: This study explored the interaction between environment and behavior and analyzed the effect of physical environment stimuli and individual differences on environmental perception. Methods: We investigated the effects of two kinds of noise sensitivities (high sensitivity and low sensitivity) and three kinds of noise types (quiet, road traffic noise, and speech noise) on working memory and noise annoyance of college students through questionnaires and experiments. Results: (i) noise sensitivity was positively correlated with neuroticism and negatively correlated with conscientiousness. (ii) The interaction between noise sensitivity and noise type significantly affected the accuracy of working memory. (iii) Both noise sensitivity and the main effect of noise type significantly affected the response time of working memory. (iv) The interaction between noise sensitivity and noise type significantly affects noise annoyance. Conclusion: There were significant differences in working memory performance and subjective noise annoyance among individuals with different levels of noise sensitivity.

Objectives: To assess the effects of noise and chemical exposure on peripheral and central auditory pathways in normal-hearing workers exposed to chemicals or high noise levels and compare the groups with each other and with workers not exposed to either of these agents. Methods: A total of 54 normal-hearing workers were divided into three groups (chemical, noise, control) and submitted to the following assessments: conventional and extended high-frequency pure-tone audiometry; transient and distortion-product otoacoustic emissions, the inhibitory effect of the efferent auditory pathway; and Staggered Spondaic Word (SSW) and Pitch Pattern Sequence (PPS) test. Results: There were no significant differences between the groups in extended high-frequency hearing thresholds. Significantly lower amplitudes were observed in the noise group for otoacoustic emissions. There were significantly more absences of the inhibitory effect of the efferent system in the noise group. There was no difference between the groups in the SSW test, while in PPS, the noise group performed worse than the control group. Conclusion: These findings suggest that noise exposure produced deleterious effects on the workers’ peripheral and central auditory systems, despite their normal hearing thresholds. The chemical group did not have significantly different results from those of the control group. It is important that individuals exposed to noise or chemicals have their auditory pathways monitored with complementary assessments.

Background: One of the most common hearing disorders is hyperacusis, characterized by decreased sound tolerance or noise sensitivity. Objective: The present paper aimed to evaluate the validity of the Persian version of the hyperacusis questionnaire. Methods: The sample was comprised of 434 students evaluated at the Kashan University of Medical Science, Isfahan, between July 2019 and February 2020. After translation and retranslation of questionnaire, the content validity was assessed by 15 occupational health experts using content validity index (CVI) and ratio (CVR). Validity and reliability of the scale were examined by using confirmatory factor analysis, the Cronbach alpha, composite reliability (CR), and the average variance extracted (AVE) tests. Results: In the exploratory analysis of the Persian version of Khalfa hyperacusis questionnaire, 14 items were created based on three subscales) attentional, social, and emotional dimensions) which explained 46.5% of the total variances. Content validity of 14 questions was approved with CVR > 0.49 and CVI > 0.7. The Cronbach alpha, AVE, and CR indexes were calculated 0.811, 0.761, and 0.901, respectively, which showed that reliability of the scale was adequate. Conclusions: It was concluded that this Persian version of the hyperacusis questionnaire has relatively acceptable validity and reliability in Iran. Given that the tool has a small number of questions, it is easily used in different studies.