Audiology and hearing health professionals in developed and developing countries (2002), Lyn et al. (1998), and Swart et al. (1995), impacted cerumen is one of the most common ear diseases and causes of hearing loss, with prevalence rate between 7.4% and 63%. Additionally, otoscopy does not require a great deal of expertise beyond basic training and is useful to refer a child when the tympanic membrane cannot be visualized due to occlusion of the external auditory meatus by cerumen. Pure-tone audiometry screening, in which there is typically no attempt to find threshold, has been found to accurately assess hearing status in children six years and older, when trained health workers
The Net (substance) The Net (substance) The Net, in alchemy, is an alloy of copper and iron, whose crystal structure induces a network pattern on its surface. It was described in the 17th century by Sir Isaac Newton. Newton produced the substance by following what he regarded as a recipe, encoded in classical mythology, for part of the process of achieving the philosopher's stone. The relevant myth involved the god Vulcan finding his wife Venus (alchemical symbol for copper) in bed with the god Mars (alchemical symbol for iron) Newton's interpretation rested on typical alchemical associations, construing Vulcan as a stand-in for fire,