As people move through the activities of daily living at home, at work, and in social or business situations, basic auditory abilities take on functional significance. Audition makes it possible to detect and recognize meaningful environmental sounds, to identify the source and location of a sound, and, most importantly, to perceive and understand spoken language.
The ability of an individual to carry out auditory tasks in the real world is influenced not only by his or her hearing abilities, but also by a multitude of situational factors, such as background noise, competing signals, room acoustics, and familiarity with the situation. Such factors are important regardless of whether one has a hearing loss, but the effects are magnified when hearing is impaired. For example, when an individual with normal hearing engages in conversation in a quiet, well-lit setting, visual information from the speaker’s face, along with situational cues and linguistic context, can make communication quite effortless. In contrast, in a noisy environment, with poor lighting and limited visual cues, it may be much more difficult to carry on a conversation or to give and receive information. A person with hearing loss may be able to function very well in the former situation but may not be able to communicate at all in the latter.
In this chapter we examine what is known about the impact of hearing loss on adults as they function in daily life; the impact of hearing loss in the workplace; the effectiveness of sensory aids, prosthetic devices, and assistive devices; and the implications and challenges for disability determination.
Impact of Hearing Loss for Adults
It is important at the outset to distinguish between adults who have experienced an early onset of severe or profound hearing loss and adults whose hearing loss was acquired later in life. When hearing loss occurs at an early age (i.e., prelingually, defined in this report as before age 2 years), there is an impact on the development of spoken language, on reading ability and educational attainment, and, ultimately, on employability (discussed further in Chapter 7).
These persons are usually considered deaf, and a good number may use American Sign Language or a similar sign system as their preferred mode of communication. When hearing loss occurs after the development of spoken language, and particularly when it occurs slowly, as it does in aging or as the result of prolonged noise exposure, there is a loss of functional hearing ability, but other cognitive skills and competencies are not greatly affected.
The terms “hard-of-hearing” and “late deafened” are often used to describe these individuals. In the sections that follow, we examine the impact of hearing loss in adults, with only occasional reference to etiology or time of onset. Nevertheless, each issue or research finding has greater relevance for one of these groups than for the other.