The validity of using a self-report single question as a means to detect hearing loss in an adolescent population.

OBJECTIVE: The overall objective in the study was to compare self-reported hearing based on a single question ("how good would you currently rate your hearing?") to measure hearing loss determined by audiometry in a cohort of adolescents. Prevalence of audiometrically measured hearing loss and frequencies of self-reported poor hearing as well as factors that have an impact on self-reported hearing were examined. DESIGN: Baseline and 5-year follow-up data of the Ohrkan study were used. Participants filled in a questionnaire and underwent audiometric measurements. STUDY SAMPLE: Data from 979 adolescents were analysed. Participants were 54.7% female and aged between 13 and 18 years at baseline and 17-21 years at 5-yr follow-up. RESULTS: The single question on self-reported hearing ability achieved a sensitivity of 41.9% and a positive predictive value of 7.1% at baseline. For the 5-yr follow-up, sensitivity was 40.0%, positive predictive value was 13.9%. Factors influencing self-reported poor hearing were gender, tinnitus, "muffled" ears after exposure to loud noise (e.g. after a concert) and low-frequency hearing loss. CONCLUSIONS: The single question about hearing ability used in the Ohrkan study is not sufficient to replace audiometry to detect hearing loss as defined in the study in adolescents.

A multi-layered strategy for COVID-19 infection prophylaxis in schools: A review of the evidence for masks, distancing, and ventilation.

Implications for the academic and interpersonal development of children and adolescents underpin a global political consensus to maintain in-classroom teaching during the ongoing COVID-19 pandemic. In support of this aim, the WHO and UNICEF have called for schools around the globe to be made safer from the risk of COVID-19 transmission. Detailed guidance is needed on how this goal can be successfully implemented in a wide variety of educational settings in order to effectively mitigate impacts on the health of students, staff, their families, and society. This review provides a comprehensive synthesis of current scientific evidence and emerging standards in relation to the use of layered prevention strategies (involving masks, distancing, and ventilation), setting out the basis for their implementation in the school environment. In the presence of increasingly infectious SARS-Cov-2 variants, in-classroom teaching can only be safely maintained through a layered strategy combining multiple protective measures. The precise measures that are needed at any point in time depend upon a number of dynamic factors, including the specific threat-level posed by the circulating variant, the level of community infection, and the political acceptability of the resultant risk. By consistently implementing appropriate prophylaxis measures, evidence shows that the risk of infection from in-classroom teaching can be dramatically reduced. Current studies indicate that wearing high-quality masks and regular testing are amongst the most important measures in preventing infection transmission; whilst effective natural and mechanical ventilation systems have been shown to reduce infection risks in classrooms by over 80%.

Exposure to leisure noise and intermittent tinnitus among young adults in Bavaria: longitudinal data from a prospective cohort study.

OBJECTIVES: To investigate the association between total leisure noise exposure and intermittent tinnitus among young adults. DESIGN: Data were obtained from the Ohrkan study, an ongoing prospective cohort study conducted in South Germany since 2009. Information about exposure to impulse and leisure noise, tinnitus occurrences, sociodemographic variables, and self-rated hearing ability were analysed at four time points over a period of seven and a half years. STUDY SAMPLE: Participants of the Ohrkan cohort study, who provided data about the occurrence of tinnitus for all surveys (n = 1028). RESULTS: Intermittent tinnitus was reported in the majority of the sample (60%). The risk for intermittent tinnitus increased with higher sound pressure levels from exposure to leisure noise (full model (Odds Ratio, 95%CI): 80-<85dB(A): 1.41 [1.13-1.78], 85-<90dB(A): 1.73 [1.38-2.16], >90dB(A): 2.04 [1.59-2.61]). Visiting nightclubs was a major contributor to this relationship. Of the considered covariables, self-rated hearing as "poor", and growing up in a single-parent household were significantly associated with intermittent tinnitus. CONCLUSION: Intermittent tinnitus is very frequent among young adults and is associated with high levels of leisure noise exposure. To prevent intermittent tinnitus, reduced sound pressure levels and the use of hearing protection are necessary.

Compensating for missing data in the OHRKAN cohort study examining total leisure noise exposure among adolescents.

OBJECTIVE: Investigating determinants of total leisure noise (TLN) exposure among adolescents over 7.5 years and compensating for missing data due to loss to follow-up. DESIGN: In the OHRKAN cohort study, data were collected by questionnaires at four waves. TLN was calculated from self-reported duration spent participating in 18 leisure activities. High exposure was defined as exceeding 85 dB(A) of equivalent continuous average sound pressure level (SPL) during a 40-h week. Multiple imputation (MI) and generalised estimating equations (GEE) were used to analyse odds ratios (OR) of determinants of TLN exposure and compared to complete-case analysis. STUDY SAMPLE: Closed cohort of 2148 students enrolled in grade 9 of any school in Regensburg (Germany), recruited from 2009 to 2011. RESULTS: Up to 74% of adolescents had risky TLN exposure, depending on wave. The most significant sources were discotheques, portable listening devices (PLD) and stereo systems. Higher TLN exposure was associated with time point, education, single-parent households and gender. MI under MAR assumption changed results only slightly compared to complete-case analysis. CONCLUSIONS: Prevalence of risky TLN is high during adolescence. MI reinforced trends detected in former results of OHRKAN. Preventive measures should consider the main drivers of noise exposure including changes by age and high risks groups.

Activating a Noise-Gating Algorithm and Personalizing Electrode Threshold Levels Improve Recognition of Soft Speech for Adults With CIs.

OBJECTIVE: In contrast to the moderate presentation levels most commonly used in clinical practice, speech encountered in everyday life often occurs at low levels, such as when a conversational partner whispers or speaks from another room. In addition, even when the overall signal level is moderate, levels for particular words or speech sounds, such as voiceless consonants, can be considerably lower. Existing techniques for improving recognition of low-level speech for cochlear implant users include using a wider input dynamic range and elevating electrode threshold levels (T-levels). While these techniques tend to positively impact recognition of soft speech, each has also been associated with drawbacks. Recently, a noise-gating (NG) algorithm was reported, which works by eliminating input to an electrode when signal level in the associated frequency channel is at or below a predetermined threshold. Available evidence suggests that activation of this algorithm can improve recognition of sentences presented at low levels (35 to 50 dB SPL), though it remains unclear whether the benefits will be equally evident with both manufacturer default and individually optimized T-levels. The primary aim of this study was therefore to evaluate the independent and combined effects of NG activation and T-level personalization. METHODS: Twenty adults between the ages of 25 and 77 years (M = 54.9 years, SD = 17.56) with postlingually acquired profound hearing loss completed testing for this study. Participants were fit with an Advanced Bionics Naida CI Q90 speech processor, which contained four programs based on each participant's existing everyday program. The programs varied by the NG algorithm setting (on, off) and T-level method (default 10% of M-level, personalized based on subjective ratings of "very quiet"). All participants completed speech sound detection threshold testing (/m/, /u/, /a/, /i/, /s/, and /∫/), as well as tests of monosyllabic word recognition in quiet (45 and 60 dB SPL), sentence recognition in quiet (45 and 60 dB SPL), and sentence recognition in noise (45-dB SPL speech, +10 dB SNR). RESULTS: Findings demonstrated that both activating NG and personalizing T-levels in isolation significantly improved detection (speech sounds) and recognition (monosyllables, sentences in quiet, and sentences in noise) of soft speech, with their respective individual effects being comparable. However, the lowest speech sound detection thresholds and the highest speech recognition performance were identified when NG was activated in conjunction with personalized T-levels. Importantly, neither T-level personalization nor NG activation affected recognition of speech presented at 60 dB SPL, which suggests the strategies should not be expected to interfere with recognition of average conversational speech. CONCLUSIONS: Taken together, these data support the clinical recommendation of personalizing T-levels and activating NG to improve the detection and recognition of soft speech. However, future work is needed to evaluate potential limitations of these techniques. Specifically, speech recognition testing should be performed in the presence of diverse noise backgrounds and home-trials should be conducted to determine processing effects on sound quality in realistic environments.

A clinical comparison of DPOAE fine structure reduction methods.

OBJECTIVE: To evaluate two real-time methods for reducing distortion product otoacoustic emission (DPOAE) fine structure in terms of DPOAE amplitude and fine structure depth. DESIGN: A prospective, repeated-measures design was used to assess DPOAE characteristics in response to a conventional stimulation method (Conv.), as well as for methods implementing either a generic suppressor tone (Supp.) or frequency modulation of the f2 primary tone (FM). STUDY SAMPLE: Eighty-three young adults (58 females) between the ages of 20 and 34 years with normal hearing completed testing for this study. RESULTS: Use of the Conv. and FM methods resulted in consistently higher DPOAE levels relative to the Supp. method, with average advantages of 6 and 5 dB, respectively. For all methods, increased fine structure depth was observed for stimulation with lower level (25-45 dB SPL) and lower frequency (1000-3000 Hz) primary tones. Finally, use of the Supp. and FM methods resulted in significantly decreased fine structure depth relative to the Conv. method. CONCLUSION: Through frequency modulation of the f2 primary tone, it was possible to reduce the depth of fine structure across a clinically meaningful range of stimulation levels and frequencies without concomitant reduction in DPOAE amplitude.

Photoacoustic gas monitoring for anesthetic gas pollution measurements and its cross-sensitivity to alcoholic disinfectants.

BACKGROUND: Real-time photoacoustic gas monitoring is used for personnel exposure and environmental monitoring, but its accuracy varies when organic solvents such as alcohol contaminate measurements. This is problematic for anesthetic gas measurements in hospitals, because most disinfectants contain alcohol, which could lead to false-high gas concentrations. We investigated the cross-sensitivities of the photoacoustic gas monitor Innova 1412 (AirTech Instruments, LumaSense, Denmark) against alcohols and alcoholic disinfectants while measuring sevoflurane, desflurane and isoflurane in a laboratory and in hospital during surgery. METHODS: 25 mL ethyl alcohol was distributed on a hotplate. An optical filter for isoflurane was used and the gas monitor measured the 'isoflurane' concentration for five minutes with the measuring probe fixed 30 cm above the hotplate. Then, 5 mL isoflurane was added vaporized via an Anesthetic Conserving Device (Sedana Medical, Uppsala, Sweden). After one-hour measurement, 25 mL isopropyl alcohol, N-propanol, and two alcoholic disinfectants were subsequently added, each in combination with 5 mL isoflurane. The same experiment was in turn performed for sevoflurane and desflurane. The practical impact of the cross-sensitivity was investigated on abdominal surgeons who were exposed intraoperatively to sevoflurane. A new approach to overcome the gas monitor's cross-sensitivity is presented. RESULTS: Cross-sensitivity was observed for all alcohols and its strength characteristic for the tested agent. Simultaneous uses of anesthetic gases and alcohols increased the concentrations and the recovery times significantly, especially while sevoflurane was utilized. Intraoperative measurements revealed mean and maximum sevoflurane concentrations of 0.61 ± 0.26 ppm and 15.27 ± 14.62 ppm. We replaced the cross-sensitivity peaks with the 10th percentile baseline of the anesthetic gas concentration. This reduced mean and maximum concentrations significantly by 37% (p < 0.001) and 86% (p < 0.001), respectively. CONCLUSION: Photoacoustic gas monitoring is useful to detect lowest anesthetic gases concentrations, but cross-sensitivity caused one third falsely high measured mean gas concentration. One possibility to eliminate these peaks is the recovery time-based baseline approach. Caution should be taken while measuring sevoflurane, since marked cross-sensitivity peaks are to be expected.

Feedback reduction system influence on additional gain before feedback and maximum stable gain in open-fitted hearing aids.

OBJECTIVE: The primary purpose of this study was to update existing data on additional gain before feedback and maximum stable gain in commercially available, open-fit hearing instruments. A secondary purpose was to evaluate ratings of sound quality with feedback reduction systems active. DESIGN: Additional gain before feedback, maximum stable gain and subjective sound quality ratings were obtained for six commercially available hearing instruments utilising modern feedback reduction systems. STUDY SAMPLE: Twenty adults (22-46 years) with normal hearing participated in gain measurement testing. Thirty adults (22-39 years) with normal hearing provided ratings of sound quality. RESULTS: Mean additional gain before feedback for 2000-4000 Hz ranged from 5 to 16 dB across manufacturers. Mean maximum stable gain in the same frequency region ranged from 25 to 35 dB across manufacturers. However, meaningful performance differences between participants within each given manufacturer were also identified. Sound quality ratings were not related to the type of feedback reduction algorithm. CONCLUSIONS: AGBF and MSG continue to vary significantly both across manufacturers as well as individual ears within a given manufacturer. User satisfaction and performance with hearing aids might be improved by identifying the feedback reduction system optimal for the individual patient.

Longitudinal analysis of leisure noise exposure among adolescents with special focus on portable listening devices: the OHRKAN cohort study.

The aim was to investigate leisure noise exposure and sociodemographic determinants of risky leisure noise exposure over five years in 2148 students visiting grade 9 of any school type in a German city from 2009-2011. Within the OHRKAN cohort study, leisure noise exposure was calculated from literature-retrieved sound pressure levels (SPLs) and self-reported duration of 18 leisure activities at baseline and two follow-ups. Risky exposure was defined as exceeding 85 dB(A) averaged over a 40-h-week. Determinants of risky total leisure noise (TLN) exposure and risky exposure to portable listening devices (PLDs) were investigated using generalised estimating equations (GEEs). Up to 73% of students exceeded noise levels of 85 dB(A) at some timepoint. The noise exposure and importance of different leisure activities changed with increasing age. Risky exposure to TLN and PLDs was associated with lower education, single parent households and being male. Risky PLD exposure was additionally associated with a migrant background. Current prevention measures for leisure noise exposure must be extended to at-risk groups. Besides enhancing campaigns in lower education schools, acoustical insulation in sports halls, noise warnings on tools or in videogames could address especially men. Migrants need education about healthy PLD use in their native language if necessary.

Efficiencies and noise levels of portable surgical smoke evacuation systems.

Surgical smoke resulting from electrocauterization is a health risk for operating room personnel. The U.S. National Institute for Occupational Safety and Health recommends the use of local exhaust ventilation such as a portable smoke evacuation system to reduce surgical smoke, but its efficiency has never been assessed under experimental conditions. In this study, particle filtration efficiencies of five commercially available smoke evacuation systems were investigated in a model operating room. Two cutting angles, the devices' suction capacities, three unidirectional displacement flow rates, and the noise exposures were considered. Results demonstrated that portable smoke evacuation systems reduce surgical smoke up to 99% under optimal conditions. A cutting angle of 45°, the device's maximum suction capacity, and a unidirectional displacement flow rate of 10,500 m³/hr were advantageous. Sound levels ranged between 51-69 dBA and exceeded recommended threshold limits, if used with medium or maximum suction capacity. Hence, portable smoke evacuation systems are beneficial and are recommended. However, a combination with general unidirectional room ventilation and a strict limitation of the use of electrocauterization is strongly advised.

Estimation of Minor Conductive Hearing Loss in Humans Using Distortion Product Otoacoustic Emissions.

OBJECTIVES: Conductive hearing loss (CHL) systematically alters distortion product otoacoustic emission (DPOAE) levels through attenuation of both the primary tones and the evoked response by the middle ear, as well as through modification of the effective L1-L2 relationship within the cochlea. It has been postulated that, if optimal primary tone level relationships for an ear without CHL are known or can be estimated accurately and a CHL can be presumed to attenuate both primary tones to a similar extent, the adjustment to L1 required to restore an optimal L1-L2 separation following CHL induction can be utilized to estimate CHL magnitude objectively. The primary aim of this study was to assess the feasibility of objectively estimating experimentally produced CHL in humans by comparing CHL estimates resulting from DPOAE- and pure-tone audiometry-based methods. A secondary aim was to compare the accuracy of DPOAE-based CHL estimates when obtained using generic, as opposed to ear-specific, optimal primary tone level formula parameters. DESIGN: For a single ear of 30 adults with normal hearing, auditory threshold for a 1 kHz tone was obtained using automated Békésy audiometry at an ear-canal pressure of 0 daPa, as well as at a negative pressure sufficient for increasing threshold by 3 to 10 dB. The difference in threshold for the ear-canal pressure conditions was defined as the pure-tone audiometry-based estimate of CHL (CHLPT). For the same two ear-canal pressures, optimal DPOAE primary tone level relationships were identified for f2 = 1 kHz. Specifically, for 20 ≤ L2 ≤ 70 dB SPL, L1 was varied 15 dB above and below the recommendation of L1 = 0.49 L2 + 41 (dB SPL). The difference between the optimal L1-L2 relationships for the two pressure conditions was defined as ΔL1OPT. A DPOAE-based estimate of CHL (CHLDP) was obtained using the formula CHLDP = ΔL1OPT/(1 - a), where a represents the slope of the optimal L1-L2 relationship observed in the absence of CHL. RESULTS: A highly significant linear dependence was identified between pure-tone audiometry- and DPOAE-based estimates of CHL, r(19) = 0.71, p < 0.001. However, the correlation was only significant when ear-specific optimization formula parameters were known. Use of generic, frequency-nonspecific parameters resulted in significantly less accurate estimates than did either ear-specific (p < 0.001) or generic, frequency-specific parameters (p = 0.007). CONCLUSIONS: This study provides empirical support for a theory of how CHL, through a combination of middle ear filtering and alteration of effective primary tone level relationships within the cochlea, systematically affects DPOAE amplitude. Although CHLDP was shown to be significantly predictive of CHLPT when optimization formula parameters for a given ear, both with and without mild CHL, were known, the lack of a meaningful relationship when using generic primary tone level formula parameters significantly limits the method's potential for clinical utility.

Avoiding disconnection: An evaluation of telephone options for cochlear implant users.

OBJECTIVE: The primary aim of this study was to evaluate the effect of coupling method on telephone-based speech recognition and perceived listening difficulty in noise for cochlear implant (CI) users. A secondary aim was to evaluate potential impacts of additional processing modifications within coupling conditions, such as activating noise reducing algorithms or muting environmental microphones. DESIGN: Hochmair-Schulz-Moser sentences were bandpass-filtered (300-3400 Hz) and presented unilaterally either via telephone handset or advanced wireless streaming device in a background of cafeteria babble (signal-to-noise ratio =15 dB). Sentence recognition was scored at the word level and perceived listening difficulty was assessed via visual-analogue scale for each of five test conditions. STUDY SAMPLE: Twenty native German-speaking CI users participated. RESULTS: Repeated measures analysis of variance revealed coupling via advanced streaming significantly improved sentence recognition and reduced listening difficulty, when compared to either telecoil or acoustic coupling configurations. In addition, program modifications further increased benefit within a coupling condition. CI users who exhibited the most difficulty during basic acoustic coupling were most likely to benefit from advanced wireless streaming. CONCLUSION: CI users have several options for improving speech recognition and decreasing listening difficulty over the telephone when listening in noisy environments.

Usage of personal music players in adolescents and its association with noise-induced hearing loss: A cross-sectional analysis of Ohrkan cohort study data.

OBJECTIVE: To describe personal music player (PMP) usage among adolescents, sociodemographic determinants and association with audiometric notches. DESIGN: Audiometric evaluation to assess hearing status, and standardized questionnaires to evaluate PMP listening behaviors, leisure noise exposures and self-reported hearing loss symptoms. Sociodemographic information was collected using a parent questionnaire. Noise exposure by PMP usage equivalent for a 40 h week was estimated based on self-reported volume and duration of use. STUDY SAMPLE: A total of 2143 students (54% females) attending 9th grade in Regensburg, Germany, during 2009 to 2011. RESULTS: Overall, 85% of the students reported using PMPs. Exposure level exceeded 80 dB(A) in approximately one third, and 85 dB(A) in one quarter, of those who used PMP. An audiometric notch was found in 2.3% of participants, but was not significantly associated with higher PMP exposure. CONCLUSIONS: PMP exposure above the occupational limits of 80 and 85 dB(A) set by the Directive 2003/10/EC may be a risk factor for developing noise-induced hearing loss. Educational measures to ameliorate high risk behaviors in PMP usage are needed, particularly for socially disadvantaged groups.

Audiometric notch and extended high-frequency hearing threshold shift in relation to total leisure noise exposure: An exploratory analysis.

BACKGROUND: Studies investigating leisure noise effect on extended high frequency hearing are insufficient and they have inconsistent results. The aim of this study was to investigate if extended high-frequency hearing threshold shift is related to audiometric notch, and if total leisure noise exposure is associated with extended high-frequency hearing threshold shift. MATERIALS AND METHODS: A questionnaire of the Ohrkan cohort study was used to collect information on demographics and leisure time activities. Conventional and extended high-frequency audiometry was performed. We did logistic regression between extended high-frequency hearing threshold shift and audiometric notch as well as between total leisure noise exposure and extended high-frequency hearing threshold shift. Potential confounders (sex, school type, and firecrackers) were included. RESULTS: Data from 278 participants (aged 18-23 years, 53.2% female) were analyzed. Associations between hearing threshold shift at 10, 11.2, 12.5, and 14 kHz with audiometric notch were observed with a higher prevalence of threshold shift at the four frequencies, compared to the notch. However, we found no associations between total leisure noise exposure and hearing threshold shift at any extended high frequency. CONCLUSION: This exploratory analysis suggests that while extended high-frequency hearing threshold shifts are not related to total leisure noise exposure, they are strongly associated with audiometric notch. This leads us to further explore the hypothesis that extended high-frequency threshold shift might be indicative of the appearance of audiometric notch at a later time point, which can be investigated in the future follow-ups of the Ohrkan cohort.

Average optimal DPOAE primary tone levels in normal-hearing adults.

OBJECTIVE: Despite great progress towards optimizing DPOAE primary tone characteristics, factors such as stimulus and intra-subject emission variability have not been addressed. The purpose of this study was to identify optimal primary tone level relationships when these sources of variability were acknowledged, and to identify any influences of test frequency. DESIGN: Following coupler-based measurements assessing primary tone level stability, two experiments were conducted. In experiment 1, DPOAE test-retest reliability without probe replacement was measured for f2 = 1-6 kHz with L1 = L2 = 65 dB SPL. In experiment 2, optimal L1-L2 relationships were identified for f2 = 1-6 kHz. For 20 ≤ L2 ≤ 75 dB SPL, L1 was varied 15 dB SPL above and below the recommendation of L1 = 0.4 L2 + 39 [dB SPL]. STUDY SAMPLE: Eleven normal-hearing adults participated in experiment 1. Thirty normal-hearing adults participated in experiment 2. RESULTS: Stimulus variability did not exceed 0.1 dB SPL. DPOAE reliability testing revealed an across-frequency mean standard error of measurement of 0.52 dB SPL. The average optimal L1-L2 relationship was described by L1 = 0.49 L2 + 41 [dB SPL]. A significant effect of frequency was identified for 6 kHz. CONCLUSION: Including relevant sources of variability improves internal validity of a primary tone level optimization formula.

Early indication of noise-induced hearing loss from PMP use in adolescents: A cross-sectional analysis.

CONTEXT: Distortion product otoacoustic emissions (DPOAEs) may indicate preclinical noise-induced hearing loss (NIHL) in adolescents from unsafe personal music player (PMP) use. AIMS: The objective, therefore, was to observe preclinical signs of NIHL in 9th grade adolescents with clinically normal hearing by comparing DPOAE signals between different levels of A-weighted equivalent PMP exposure. SETTINGS AND DESIGN: Subjects were recruited from all secondary-level schools located in the city of Regensburg, Germany during two academic years 2009/2010 and 2010/2011. SUBJECTS AND METHODS: A-weighted equivalent sound pressure levels (SPLs) for a 40-hour work week (LAeq,40h) were estimated from questionnaire responses on output and duration of PMP use of the previous week. Subjects were then categorized into four levels of exposure: <80, 80-85, >85 to <90, and ≥90 A-weighted Decibel [dB(A)]. DPOAE signals were collected by trained audiological staff, applying a standard optimized protocol, at the Department of Otorhinolaryngology of the University Hospital Regensburg. STATISTICAL ANALYSIS USED: Mean DPOAE signals were compared between levels by unpaired t test. Novel linear regression models adjusting for other leisure noise exposures and with outcome variables DPoutcome and 4 kilo Hertz (kHz) DPOAEs estimated effects between levels. RESULTS: A total of 1468 subjects (56% female, mostly aged 15 or 16 years) were available for analysis. Comparison of DPOAE means by PMP exposure typically showed no greater than 1 dB difference between groups. In fact, comparisons between ≥90 dB(A) and <80 dB(A) presented the least differences in magnitude. Both DPoutcome and 4 kHz linear regression models presented a weak association with the 4-level PMP exposure variable. An expected dose-response to PMP exposure was not observed in any analyses. CONCLUSIONS: DPOAE signal strength alone cannot indicate preclinical NIHL in adolescents.

Total leisure noise exposure and its association with hearing loss among adolescents.

OBJECTIVE: To investigate total leisure noise exposure among adolescents and to assess its association with hearing. DESIGN: Based on self-reported time spent on 19 leisure activities and associated mean sound pressure levels reported in the literature, total leisure noise exposure was evaluated and compared to noise at work limits (> 85 dB(A) = hazardous) in a cross-sectional survey. Tympanometry and pure-tone audiometry was performed in sound isolated rooms. STUDY SAMPLE: The study sample consists of 2143 pupils attending grade nine in any school in a German city 2009-2011 (mean age: 15.4 years; range: 13-19 years). Audiometric data were available for 1837 (85.8%) pupils (53.9% girls). RESULTS: 41.9% of the 2143 adolescents who had provided self-reported data on leisure activities associated with noise exposure were estimated to be hazardously exposed to leisure time noise. The interaction of gender with total leisure time noise exposure was not significant. No association between leisure time noise exposure and audiometric notches could be detected. CONCLUSION: While hearing loss seems seldom in this age group, a high proportion of adolescents aged 15-16 years are exposed to noise levels during leisure time bearing long-term risks of hearing loss.

Perfusion Electronic Record Documentation Using Epic Systems Software.

This paper describes the design and use of Epic Systems software for documentation of perfusion activities as part of the patient electronic medical record. The University of Wisconsin Hospital and Clinics adapted the Anesthesia software module and developed an integrated perfusion/anesthesia record for the documentation of cardiac and non-cardiac surgical procedures. This project involved multiple committees, approvals, and training to successfully implement. This article will describe our documentation options, concepts, design, challenges, training, and implementation during our initial experience.

Infection Prevention and the Protective Effects of Unidirectional Displacement Flow Ventilation in the Turbulent Spaces of the Operating Room.

BACKGROUND: Unidirectional displacement flow (UDF) ventilation systems in operating rooms are characterized by a uniformity of velocity ≥80% and protect patients and operating room personnel against exposure to hazardous substances. However, the air below the surgical lights and in the surrounding zone is turbulent, which impairs the ventilation system's effect. AIM: We first used the recovery time (RT) as specified in International Organization for Standardization 14644 to determine the particle reduction capacity in the turbulent spaces of an operating room with a UDF system. METHODS: The uniformity of velocity was analyzed by comfort-level probe grid measurements in the protected area below a hemispherical closed-shaped and a semi-open column-shaped surgical light (tilt angles: 0°/15°/30°) and in the surrounding zone of a research operating room. Thereafter, RTs were calculated. RESULTS: At a supply air volume of 10,500 m3/h, the velocity, reported as average uniformity ± standard deviation, was uniform in the protected area without lights (95.8% ± 1.7%), but locally turbulent below the hemispherical closed-shaped (69.3% ± 14.6%), the semi-open column-shaped light (66.9% ± 10.9%), and in the surrounding zone (51.5% ± 17.6%). The RTs ranged between 1.1 and 1.7 min below the lights and 3.5 ± 0.28 min in the surrounding zone and depended exponentially on the volume flow rate. CONCLUSIONS: Compared to an RT of ≤20 min as required for operating rooms with mixed dilution flow, particles here were eliminated 12-18 times more quickly from below the surgical lights and 5.7 times from the surrounding zone. Thus, the effect of the lights was negligible and the UDF's retained its strong protective effect.

The prevalence of audiometric notches in adolescents in Germany: The Ohrkan-study.

Although there is concern about increasing hearing loss in adolescents caused by leisure noise exposure, prevalence data are scarce. In an US study, about 16-17% of adolescents were affected by audiometric notches. To estimate the prevalence of audiometric notches in adolescents in Germany, baseline data of the cohort study Ohrkan, recruitment during the school years 2009/2010 and 2010/2011 were analyzed. All students in grade 9 visiting any school in the city of Regensburg were eligible for participation. Data was collected via standardized questionnaires from students and their parents. In addition, students were asked to visit the University Clinics of Regensburg for ear examination including a tympanogram and the determination of hearing thresholds in air conduction audiometry. The prevalence of audiometric notches was determined in students with normal tympanogram in both ears and complete audiometry data. Audiometric notches were defined according to criteria used to analyse US data. Overall, 2149 students (1158 girls, 991 boys mainly aged 15-16 years) of the 3846 eligible adolescents (56%) participated. Among the 1843 adolescents with complete audiometry and tympanometry data, the prevalence of audiometric notches was 2.4% (95% confidence interval 1.7-3.1%). We could not confirm the high prevalence of audiometric notches as reported in National Health and Nutrition Examination Surveys for adolescents in the US. Differences in prevalence might be at least partly due to methodical differences in audiometry. Even if empirical evidence is presently ambiguous, it is reasonable to educate young people about the potential risks of high leisure noise exposure.