Effect of Electroacupuncture on Noise-Induced Hearing Loss in Rats

Acupuncture has long been used to relieve some inner ear diseases such as deafness and tinnitus. The present study examined the effect of electroacupuncture (EA) on noise-induced hearing loss (NIHL) in animals. A NIHL rat model was established. Electroacupuncture pretreatment at 2 Hz or posttreatment at the right Zhongzhu (TE3) acupoint was applied for 1 hour. Auditory thresholds were measured using auditory brainstem responses (ABRs), and histopathology of the cochlea was examined. The results indicated that the baseline auditory threshold of ABR was not significantly different between the control (no noise), EA-only (only EA without noise), noise (noise exposure only), pre-EA (pretreating EA then noise), and post-EA (noise exposure then posttreating with EA) groups. Significant auditory threshold shifts were found in the noise, pre-EA, and post-EA groups in the immediate period after noise exposure, whereas auditory recovery was better in the pre-EA and post-EA groups than that in the noise group at the three days, one week (W1), two weeks (W2), three weeks (W3), and four weeks(W4) after noise stimulation. Histopathological examination revealed greater loss of the density of spiral ganglion neurons in the noise group than in the control group at W1 and W2. Although significant loss of spiral ganglion loss happened in pre-EA and post-EA groups, such loss was less than the loss of the noise group, especially W1. These results indicate that either pretreatment or posttreatment with EA may facilitate auditory recovery after NIHL. The detailed mechanism through which EA alleviates NIHL requires further study.

Variation in interpeak latencies of auditory brainstem responses with age in male adults:An observation

Introduction and Aim: Aging of the auditory pathway is a complex phenomenon consisting of changes in the auditory processing along with a significant elevation of the hearing threshold. The aim of our study was to see the variation in interpeak latencies (IPLs) of Auditory Brainstem Responses (ABRs) with advancing age in males. Materials and Methods: It was an observational study conducted on 60 Indian male subjects aged between 20 and 80 years divided into three groups on the basis of age: Group 1: 20-40 years, Group 2: 41-60 years and Group 3: 61-80 years. Auditory threshold and ABRs were recorded and analysed for interpeak latencies (IPLs) – I-III,I-V and III-V in msec.The comparison of data between the groups was done using one – way ANOVA and Tukey Kramer multiple comparison test. The results were considered significantly different between the groups when ‘P value’ was ? 0.05. Results: It was found that there was no significant difference in the auditory threshold and interpeak latencies (IPLs) when comparison was made between the three groups. Conclusion: Hence we conclude thatage does not have any significant influence on neural conduction time of the auditory pathway which is represented by the IPLs in ABRs.

Cortical Neurophysiologic Correlates of Auditory Threshold in Adults and Children With Normal Hearing and Auditory Neuropathy Spectrum Disorder

Purpose Auditory threshold estimation using the auditory brainstem response or auditory steady state response is limited in some populations (e.g., individuals with auditory neuropathy spectrum disorder [ANSD] or those who have difficulty remaining still during testing and cannot tolerate general anesthetic). However, cortical auditory evoked potentials (CAEPs) can be recorded in many such patients and have been employed in threshold approximation. Thus, we studied CAEP estimates of auditory thresholds in participants with normal hearing, sensorineural hearing loss, and ANSD. Method We recorded CAEPs at varying intensity levels to speech (i.e., /ba/) and tones (i.e., 1 kHz) to estimate auditory thresholds in normal-hearing adults ( n = 10) and children ( n = 10) and case studies of children with sensorineural hearing loss and ANSD. Results Results showed a pattern of CAEP amplitude decrease and latency increase as stimulus intensities declined until waveform components disappeared near auditory threshold levels. Overall, CAEP thresholds were within 10 dB HL of behavioral thresholds for both stimuli. Conclusions The above findings suggest that CAEPs may be clinically useful in estimating auditory threshold in populations for whom such a method does not currently exist. Physiologic threshold estimation in difficult-to-test clinical populations could lead to earlier intervention and improved outcomes.

Association between Anemia and Auditory Threshold Shifts in the US Population: National Health and Nutrition Examination Survey

Existing evidence indicates that both iron deficiency anemia and sickle cell anemia have been previously associated with hearing loss. However, human data investigating the association between anemia and auditory threshold shifts at different frequencies in the adolescent, adult and elderly population are extremely limited to date. Therefore, this cross-sectional study used the dataset from the US National Health and Nutrition Examination Survey from 2005 to 2012 to explore differences in low- or high-frequency hearing thresholds and hearing loss prevalence between participants with and without anemia. A total of 918 patients with anemia and 8213 without anemia were included. Results indicated that low- and high-frequency pure tone average were significantly higher in patients with anemia than that in those without anemia in the elderly, but not in adult or adolescent population. In addition, the prevalence of low-frequency hearing loss but not high-frequency hearing loss was also higher in patients with anemia than in those without anemia in the elderly population. After adjusting various confounders, multiple regression models still indicated that patients with anemia tended to have larger threshold shift. In conclusion, anemia was associated with auditory threshold shifts in the elderly population, especially those vulnerable to low-frequency hearing loss.

Noise Exposure and Hearing Loss on Field Operator Compressor House Area

Introduction: Noise is one of the physical hazards that can not be separated from the industrial environment which causes noise that arises as the result of production activities. The Auditory and non-auditory impacts can affect the workers. This study aims to analyze the relation between intensity of noise with auditory threshold value on the field operators who work in the compressor house area. Method: This was an observational analytic using a cross-sectional design. The population was the overall number of workers and the sample was 32 peoples, determined using simple random sampling method. The independent variables in this study were the noise intensity, age and working period meanwhile the dependent variable was the auditory threshold value. Data were obtained by field observations and the results of questionnaires. The collected data were analyzed using Pearson Correlation tests. Result and Discussion: There was a relation between noise intensity with right ear auditory threshold value (p = 0.009) but no relation with left ear auditory threshold value (p = 0.085). Age has no relation with right ear auditory threshold value (p = 0.161) and left ear auditory threshold value (p = 0.169). The working period has no relation with right ear auditory threshold value (p = 360) and left ear auditory threshold value ( p= 0,173). Conclusion: The conclucion is the noise intensity has a relation with the exixtence of right ear hearing disturbance.