Ergonomics and Aging - Fundamentals and Assessment Tools for Occupational Ergonomics - page 407

Spoken language comprehension may also be a significant job-related skill depending on the occu-
pation. Given that spoken language comprehension heavily involves hearing ability, which declines
with age, one would expect significant difficulties related to listening comprehension. However, older
adults rarely complain of difficulties understanding speech (Burke and Harrold, 1988). Yet, research
has found some age-associated decrements with respect to listening comprehension. For example,
Titone et al. (2000) found evidence that older adults do not adjust their listening behavior to meet
the demands of increased difficulty during language processing. In contrast, studies have shown that
older adults do adjust their language processing strategies when other text demands increase, such as per-
ceptual difficulty (e.g., Pichora-Fuller et al., 1995). For a task identifying sentence-final words presented
with varying degrees of noise where words were either predictable or unpredictable, older adults com-
pensated for difficult listening conditions by taking advantage of supportive contextual information to
a greater extent compared to younger adults (Pichora-Fuller et al., 1995). Additional research exploring
the effects of listening in distracting environments, demonstrated that older adults' listening comprehen-
sion declines are primarily related to hearing decrement (Schneider et al., 2000). Hence, while older
adults can use compensatory mechanisms to maintain listening comprehension, they would benefit
from working in environments that do not have noise distractions.
The ability to understand written discourse, such as legal documentation, contractual materials, and
training manuals, is essential in the work environment. To successfully apply for a job, potential employ-
ees must complete the application and when offered a position, they must be able to read and compre-
hend the terms of employment. When faced with learning to use new office equipment, workers must
comprehend instructional materials. According to the situation model approach to comprehension
(van Dijk and Kintsch, 1983), readers determine the meaning of text by interpreting it in terms of
what they already know and drawing inferences (i.e., making conclusions that are not explicitly
stated). Recent evidence suggests that older adults may be at a disadvantage when they have to draw infer-
ences in novel situations where they cannot utilize their prior knowledge (Hancock et al., 2005).
Factors that might improve older adults' comprehension of written instructions such as those pre-
sented on office equipment include the use of large font sizes to accommodate visual deficits, simplified
sentence structure, and nontechnical terminology presented at the maximum of a sixth-grade reading
level (Wickens and Hollands, 1999). Other solutions that might facilitate comprehension and retention
of written materials include the use of elaborative memory strategies (Qualls et al., 2001) and the use of
explicit signals that highlight the main ideas and relations in the text (Meyer et al., 1998). Consistent with
the work of Hancock et al. (2005), procedures should be explicitly stated so that older adults do not have
to rely on inferential information.
17.4 Memory
Coupled with the ability to comprehend instructional materials, memory is another age-sensitive cogni-
tive factor that might impact many aspects of an older worker's performance. For example, to use office
technology a worker must remember the procedures involved in operating a device, but he or she may
also be required to initiate use at specific times or simultaneously store and manipulate incoming infor-
mation during use. As the next sections illustrate, specific types of memory decline with age whereas
others are spared (Smith, 2002).
Working memory tasks require temporary storage and manipulation of information in memory
(Baddeley and Hitch, 1974). The mental calculation required during a visit to the warehouse for office
supplies is an example of a working memory task because a person must mentally calculate the cost
of the items being purchased by constantly updating the total for the items placed on and removed
from the corporate invoice. Age-related differences in working memory are well documented (Craik,
2000) and there is some evidence that working memory decrements increase with task complexity
(Craik et al., 1990).
One instance where age-related differences in working memory might impact an older adult's inter-
action with office technology is in the use of telephone voicemail menu systems. Older workers using