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.
Definition of Speech Impairment. A speech impairment is a condition in which the ability to produce speech sounds that are necessary to communicate with others is impaired. Speech impairments can be mild, such as occasionally mispronouncing a couple of words, to severe, such as not being able to produce speech sounds at all. We rely on speech as one of the primary methods of communicating with others. An impairment in speech can significantly impact our ability to communicate.