Tin, lead and their alloys, due to their low melting temperatures and wide availability, are the most commonly used solder materials. In fact, lead has been used as a soldering metal for water pipes (also made of lead) even in Roman times, hence the scientific name for lead, Plumbum. Mechanical Properties.
hearing impairment - impairment of the sense of hearing. hearing disorder. disability, disablement, handicap, impairment - the condition of being unable to perform as a consequence of physical or mental unfitness; reading disability; hearing impairment. deafness, hearing loss - partial or complete loss of hearing.
What Is Hearing Impairment? Hearing impairment occurs when there's a problem with or damage to one or more parts of the ear. Conductive hearing loss results from a problem with the outer or middle ear, including the ear canal, eardrum, or ossicles.