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
Substance theory is Descartes' substance dualism. Baruch Spinoza denied Descartes' "real distinction" between mind and matter. Substance, according to Spinoza, is one and indivisible, but has multiple "attributes". He regards an attribute, though, as "what we conceive as constituting the [single] essence of substance". The single essence of one substance can be conceived of as material and also, consistently, as mental. What is ordinarily called the natural world, together with all the individuals in it, is immanent in God: hence his famous phrase "deus sive natura" ("God or Nature"). John Locke views substance through a corpuscularian lens where it exhibits two types