Should Dentists Mandatorily Wear Ear Protection Device to Prevent Occupational Noise-induced Hearing Loss? A Randomized Case-Control Study.

Objectives: Dentists are constantly exposed to high-frequency noise at their workplace that increases the risk of occupational noise-induced hearing loss (ONIHL). Even though dentists acknowledge about the noisy dental workplace, hearing protection devices or ear protection devices (EPD) are not commonly used by dentists. No study has yet provided any evidence on how effective EPDs can be in reducing the temporary threshold shift and damage to the outer, middle and inner ears. The aim of this article is to evaluate and compare the changes in the hearing acuity and temporary threshold shift (TTS) in dentists who wear EPDs when compared with those who do not use EPDs. Materials and Methods: Sixty-four dental clinicians were randomly divided into two groups: Group 1 (performed ultrasonic scaling without EPDs) and Group 2 (performed ultrasonic scaling with EPDs). Their hearing threshold was checked by using pure tone audiometry, stapedial acoustic reflexes, and otoacoustic emission (OAE) before and after 45 mins of ultrasonic scaling. The intergroup and intragroup comparison was done. All the outcome measures from pre- and post-scaling across the ears, groups, and frequencies among groups were done using mixed-effects analysis of variance. A P-value of less than 0.05 was considered to be statistically significant. Results: EPDs were effective in reducing the immediate TTSs. Immediately upon exposure to high-frequency noise, the alterations in the hearing threshold and stapedial reflex OAE were less in the group that used EPDs. Conclusion: EPDs should be mandatorily worn by dentists to prevent accumulation of temporary shifts in the hearing acuity, which in long-term can lead to permanent hearing loss.

The Influence of Cartoons Soundscape Irrelevant Sound Effects on young children's Auditory Processing and Working memory skills.

BACKGROUND: Irrelevant sound or speech effect (ISE) affects an individual's serial recall task of visual and auditory presentations. Cartoon soundscape mimics irrelevant sound effect hypothesis. A constant and repeated exposure to cartoons in early childhood should influence children's auditory learning or recall performance. PURPOSE: To investigate the effects of cartoons' soundscape irrelevant sound effects on young children's auditory processing and working memory skills. RESEARCH DESIGN: A cross-sectional study was used to observe the influence of the cartoon soundscape irrelevant sound effects on children. STUDY SAMPLE: Sixty young children with normal hearing in the age range 5-6years were exposed to cartoons (Indian plus Non-Indian) considered for the study. DATA COLLECTION AND ANALYSIS: Pitch Pattern Test (PPT), Duration Pattern Test (DPT), and Corsi-Block working memory apparatus were applied to the participants exposed to cartoons. The data obtained were compared statistically in terms of the groups' performances. RESULTS: There was a significant difference in PPT (p=.023) and DPT (p=.001) between the cartoon exposed and non-exposed groups. In contrast, there was no significant difference between the two groups in Corsi-Block working memory(p>0.05). CONCLUSION: Cartoon soundscape irrelevant sound or speech affects young children's auditory processing skills. The visual-spatial recall follows a different developmental pattern in young children without recoding to phonological aspects. It is predicted that our study findings might help determine the ill effects of cartoons on the auditory and language development process.

Influence of Auditory Training on Acceptable Noise Level Scores in Elderly Persons with Hearing Impairment.

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.

Leaching of organic matters and formation of disinfection by-product as a result of presence of microplastics in natural freshwaters.

Microplastics (MPs) are ubiquitous in the environment that may cause negative impacts on the aquatic organisms and human health. They exist in water and wastewater, which are from several sources, such as inappropriate disposal and littering. Therefore, it is important to evaluate the characteristics of MPs in different water types and oxidation processes and study dissolved organic carbon (DOC) leaching and chloroform formation. A commonly existing plastic matter, polyethylene (PE) was placed in different waters and gone through the Fenton-like reaction and the chlorination. The result showed that the PE leached nearly a similar amount of DOC (<1 mg L-1), which was regardless of the water types and under low-dosed irradiation/dark environment. The leached DOC caused the chloroform formation after the chlorination in the waters. During the Fenton-like reaction with the PE, a higher amount of leached DOC (∼3 mg L-1) was detected compared with that in the chlorination (∼0.8 mg L-1). The degree of DOC leaching from the PE caused by the oxidation processes was reflected by the degree of surface structural damage on the PE. However, the chlorination resulted in a higher chloroform formation from the PE (∼20 µg L-1) as the Fenton-like reaction degraded the chloroform. The higher the sodium hypochlorite concentration, the higher the chloroform concentration. When the chloroform existed in the water with the PE, adsorption of chloroform onto the PE was initially observed; however the rate of volatilization would be higher than the rate of adsorption eventually. This study offers useful information for the risk assessment of MPs in our fresh water and drinking water and possible mitigation strategies.

Effect of Carnatic Music Listening Training on Speech in Noise Performance in Adults.

BACKGROUND AND OBJECTIVES: Music listening has a concomitant effect on structural and functional organization of the brain. It helps in relaxation, mind training and neural strengthening. In relation to it, the present study was aimed to find the effect of Carnatic music listening training (MLT) on speech in noise performance in adults. SUBJECTS AND METHODS: A total of 28 participants (40-70 years) were recruited in the study. Based on randomized control trial, they were divided into intervention and control group. Intervention group underwent a short-term MLT. Quick Speech-in-Noise in Kannada was used as an outcome measure. RESULTS: Results were analysed using mixed method analysis of variance (ANOVA) and repeated measures ANOVA. There was a significant difference between intervention and control group post MLT. The results of the second continuum revealed no statistically significant difference between post training and follow-up scores in both the groups. CONCLUSIONS: In conclusion short-term MLT resulted in betterment of speech in noise performance. MLT can be hence used as a viable tool in formal auditory training for better prognosis.

Assessment of Eustachian tube functioning following surgical intervention of Oral Submucus Fibrosis by using tympanometry & audiometry.

Oral Submucus fibrosis has been reported to cause variation in hearing sensitivity & changes in middle ear function. This study was conducted to validate the influence of OSMF and its surgical correction on middle ear function and hearing sensitivity. In this study, 20 patients (40 ears) suffering from biopsy proven OSMF (Group 2 & 3) were tested for Middle ear dysfunction and hearing sensitivity using Tympanometry & Audiometry. On Tympanometry, Type A curve was obtained in 29 ears, Type B curve in 11 ears preoperatively. Immediate postoperatively TYPE A curve was obtained in 27 ears, TYPE B curve in 13 ears. After 1 month and 3 month Type B curve was not obtained in any ear. On Audiometry,28 ears showed normal hearing and 12 ears showed minimal conductive hearing loss preoperatively and Immediate postoperatively. Tests after 1 month and 3 months showed all 40 ears having normal hearing. Results were found statistically significant with p value 0.000 and F value of 11.331 in Tympanometry and 11.143 in Audiometry. Pearson correlation test revealed that results from both the test are highly co related (0.902). OSMF causes fibrotic changes in paratubal muscles which in addition with restricted mouth opening hampers proper Eustachian tube functioning in turn causing changes in Middle ear function. This feature is seldom/infrequently found in Group 2 and 3 and if encountered can be dealt effectively with surgical intervention.

Temporal processing and speech perception through multi-channel and channel-free hearing aids in hearing impaired.

Objective: To compare the temporal processing skills and speech in noise perception of hearing-impaired individuals through channel free and multichannel hearing aids.Design: A quasi-experimental study.Study sample: Twenty-one participants with sensory neural hearing loss were involved in the study. They were subjected to a series of temporal processing (TMTF, GDT & CMR-UCM/CM) and speech in noise test using a multichannel and channel-free hearing aid. Subsequently, they rated sound quality and hearing aid preferences. Objectively, the hearing aid signal output was acoustically analysed for modulation detection and gap detection tasks.Results: In all the test, participants manifested equal performance with the tested devices except CMR-CM task where channel-free outperformed. Acoustic analysis showed evidence of spectral and temporal distortion in channel-free hearing aid, similar to multichannel hearing aids. Finally, channel free was the most preferred hearing aid by less experienced participants.Conclusion: All the measures indicated similar performance across the tested devices and complemented one another in their explanation of study findings. Faster gain adjustments of channel free across the frequency facilitated better-comodulated masking release than that achieved with MCC. Preference for the sound quality of the channel free was based on factors, usually subjective. Channel-free hearing aid depicted spectral and envelope distortion, like MCC.

Auditory and Nonauditory Effects of Ultrasonic Scaler Use and Its Role in the Development of Permanent Hearing Loss.

PURPOSE: To evaluate the negative auditory and non-auditory effects developed immediately after using ultrasonic scalers and their potential role in the development of permanent hearing loss. MATERIALS AND METHODS: The auditory functions of 60 dental clinicians were evaluated with the pure tone audiometry test (PTA), tympanogram and the otoacoustic emission test (OAE) before and immediately after using ultrasonic scalers. The paired t-test was used to evaluate the difference in the pre- and post-exposure recordings for all three tests. RESULTS: There was a significant increase in the PTA and tympanogram test results, along with reduced OAE values immediately after using ultrasonic scalers. Hearing ability dropped by 63% to 66% immediately after using ultrasonic scalers. The maximum hearing disability was noted for low-frequency thresholds. The reduction was greater in the left than in the right ear. CONCLUSIONS: Noise-emitting devices such as ultrasonic scalers produce significant immediate auditory and non-auditory changes. It is important that dentists recognise the initial signs of hearing damage and adopt appropriate measures while working to prevent the development of permanent hearing impairment in future.

The relationship of perceived severity of tinnitus with depression, anxiety, hearing status, age and gender in individuals with tinnitus.

INTRODUCTION: The present study investigated the relationship between the perceived tinnitus severity, depressive and anxiety symptoms in individuals with tinnitus. An attempt was also made to see if any relationship exists between the perceived tinnitus severity and the age, gender or hearing status of the sufferer. MATERIALS AND METHODS: Fifty individuals (31 males, 19 females) with tinnitus (age range 19 to 60 years) were enrolled in the study. After the routine pure tone audiometry, each participant completed the Tinnitus Handicap Inventory, the State-Trait Anxiety Inventory and the Inventory of Depressive Symptomatology-Self Report-30. RESULTS: A significant correlation (r = 0.585, p pp < 0.01 respectively). Furthermore, age, gender and hearing status did not significantly influence the perceived severity of tinnitus. CONCLUSION: The results support the view that there is a strong relation between tinnitus and anxiety-depressive symptoms. Further, perceived severity of tinnitus is not influenced by age, gender and hearing status of the individual.

Relationships of Indoor, Outdoor, and Personal Air (RIOPA). Part I. Collection methods and descriptive analyses.

This study on the relationships of indoor, outdoor, and personal air (RIOPA) was undertaken to collect data for use in evaluating the contribution of outdoor sources of air toxics and particulate matter (PM) to personal exposure. The study was not designed to obtain a population-based sample, but rather to provide matched indoor, outdoor, and personal concentrations in homes that varied in their proximity to outdoor pollution sources and had a wide range of air exchange rates (AERs). This design allowed examination of relations among indoor, outdoor, and personal concentrations of air toxics and PM across a wide range of environmental conditions; the resulting data set obtained for a wide range of environmental pollutants and AERs can be used to evaluate exposure models. Approximately 100 households with residents who do not smoke participated in each of three cities in distinct locations expected to have different climates and housing characteristics: Elizabeth, New Jersey; Houston, Texas; and Los Angeles County, California. Questionnaires were administered to characterize homes, neighborhoods, and personal activities that might affect exposures. The concentrations of a suite of volatile organic compounds (VOCs) and carbonyl compounds, as well as the fraction of airborne particulate matter with a mass median aerodynamic diameter < or = 2.5 microm (PM2.5), were measured during continuous 48-hour sessions in which indoor, outdoor, and personal air samples were collected simultaneously. During the same 48-hour period, the AER (exchanges/hr; x hr(-1)) was determined in each home, and carbonyl compounds were measured inside vehicle cabins driven by a subset of the participants. In most of the homes, measurements were made twice, during two different seasons, to obtain a wide distribution of AERs. This report presents in detail the data collection methods, quality control measures, and initial analyses of data distributions and relations among indoor, outdoor, and personal concentrations. The results show that indoor sources dominated personal and indoor air concentrations of many measured VOCs and carbonyl compounds. For several measured species, personal concentrations were higher than either indoor or outdoor concentrations, indicating the presence of some sources closely related to personal activities. For some species there were no significant indoor sources in the majority of the homes; thus indoor concentrations were mainly determined by outdoor concentrations in these homes. The range of distributions of air concentrations for the measured VOCs, formaldehyde and acetaldehyde, PM2.5, and AERs were generally consistent with values reported previously in the literature. Thus associations derived from or models based on this data set that may link the influence of outdoor sources with indoor air concentrations of air toxics and PM2.5 can be relevant to other urban settings. The simultaneous measurements of indoor concentrations, outdoor concentrations, AERs, and room volumes allowed the use of a mass balance model, under the steady-state approximation, to mechanistically examine the relative contributions of indoor and outdoor sources to measured indoor concentrations on a home-by-home basis. Estimated indoor source strengths for VOCs and carbonyl compounds varied widely from home to home, consistent with the indoor-outdoor concentration patterns, as shown in scatter plots. The indoor source estimations agreed with published values for PM2.5 and with the general understanding of sources of VOCs and carbonyl compounds. The source strengths reported here, derived from hundreds of homes, are an important contribution to the literature on exposure to air toxics. For the first time for many compounds, these estimates present a cohesive set of measurements across a range of air toxics in paired indoor, outdoor, and personal samples along with AER and questionnaire results that can be used for future analyses of indoor air quality. The estimation of outdoor contributions to measured indoor concentrations provides insights about the relative importance of indoor and outdoor sources in determining indoor concentrations, the main determinant of personal exposure for most of the measured compounds. In this report simple statistical tests mainly of the pooled data were used to analyze differences by sampling site, emission source type, season, home type, and home age. Paired adult-child personal concentrations within the same home were also compared using the pooled data set. These analyses generated some intriguing results that warrant more in-depth investigation in the future.