Population-based study of environmental heavy metal exposure and hearing loss: A systematic review and meta-analysis.

Background and Objectives: Previous studies have shown an association between environmental exposure to heavy metals and hearing loss. However, the findings regarding the relationship between exposure to different metals and hearing loss development are inconsistent. To address this, we conducted a meta-analysis to explore the link between common heavy metal exposures and hearing loss. This study examined the effects of lead (Pb), cadmium (Cd), and mercury (Hg) pollution on hearing loss at various levels, and systematically reviewed the literature on manganese (Mn), barium (Ba), arsenic (As), and hearing loss. Methods: We conducted systematic searches in five major databases, including PubMed, Web of Science, Embase, Cochrane Library, and Scopus. In addition, we searched three Chinese digital libraries: CNKI, Wanfang Data, and Wipu. From an initial pool of 649 articles, we carefully screened and selected 15 articles for further analysis. The effect sizes from these selected studies were synthesized through a meta-analysis to calculate the overall effect size. Results: Our findings showed that: (1) There was a significant association between Pb and Cd exposure and hearing loss; (2) There is a proportional relationship between the increase of metal index detected in blood and hearing loss; (3) In the PTA measurement of hearing loss at different frequencies, the 4 kHz high frequency range had a stronger correlation with hearing loss than the low frequency, with OR 1.44 (1.22, 1.71); and (4) There was a more significant correlation between Barium (Ba) levels in nails and hair than in urine. Conclusions: The study presented evidence of a significant association between human hearing loss and exposure to lead (Pb) and cadmium (Cd). It not only revealed a positive correlation between blood heavy metal concentrations and the incidence of hearing loss but also highlighted that long-term exposure indicators of heavy metals were more indicative of the correlation with hearing loss. Lastly, the study recommends utilizing high frequency 4 kHz for the effective assessment and diagnosis of hearing loss caused by exposure to heavy metals.

Essential Palatal Myoclonus and Clicking Tinnitus in a Nine-Year-Old Boy-A Case Report.

The work describes a case of palatal myoclonus with distressing tinnitus in a 9-year-old boy and its successful treatment with injections of botulinum toxin. This case report discusses common questions about myoclonic-induced clicking tinnitus and provides answers. Laryngoscope, 134:397-399, 2024.

Optical measurements of eardrum vibrations and sound propagation in the ear canal for the fitting of active middle ear implants.

BACKGROUND: Middle ear implants (MEI) are for the medical rehabilitation of the hearing function in case of sound conduction hearing losses as well as cochlear hearing losses and their combinations. OBJECTIVES: An objective tool to reach the best fitting of the external worn sound processors is essential for patients who do not want or cannot participate in the fitting process. METHODS: In addition to Laser-Doppler-Vibrometry (LDV) measurement, the sound pressure was measured distant to the eardrum to attain additional information for comparison. Three groups of patients with different middle ear characteristics were examined. RESULTS: Because of the large spreading of measuring results even within a patient group with similar eardrum and middle ear conditions it is difficult to develop characteristic diagrams which represent the mean values of eardrum displacements with different sound processor adjustments being the base for normative data courses. CONCLUSIONS AND SIGNIFICANCE: The LDV measurements can be used as a tool for fitting sound processors by finding individual maximum eardrum velocities in the frequency range 125 Hz to 8 kHz. In comparison to acoustical measurements the optical measurements have advantages concerning lower variations of measurement values, higher spectral resolution, and robustness against disturbing acoustic noise, especially at low frequencies.

Remote programming of cochlear implants in users of all ages.

BACKGROUND: Remote programming for adult cochlear implant (CI) users is feasible, safe, and effective. Limited evidence, however, exists on if remote CI programming can also be productively done with paediatric CI users. AIMS/OBJECTIVES: To assess the safety and feasibility of remote CI programming in CI users for all ages. MATERIALS AND METHODS: Forty-six (25 children, 21 adults) experienced CI users were fit locally and remotely. The results of these two fitting sessions were compared in terms of safety, Impedance Field Telemetry (IFT), Maximum Comfortable Levels (MCL), Threshold Levels (THR), audiometry, fitting duration, and speech understanding. RESULTS: The subjects' safety was not compromised during any of the fitting procedures. No significant difference was found for IFT, MCL, THR, audiometry, or speech understanding for either remote or local fitting. Remote fittings took slightly longer than local fittings when only the fitting time itself was measured. CONCLUSIONS AND SIGNIFICANCE: Remote follow-up fitting is as safe, feasible, and effective as local fitting for CI users of all ages. A more extensive adoption of remote fitting may allow many CI users greater access to clinics and therefore increased benefit from CI use.