National Weather Service should work more closely with the community of people who are deaf to identify more easily understood words and descriptions.


The overall population of the world is aging. Based on projections, by 2050 at least a full 20 percent of the U.S. population, or 70 million people, will be 65 years of age or older.3 During disasters or crises, older adults are vulnerable for several reasons. They are much more likely to become casualties during a disaster, to suffer long-term psychological distress, and to recover economically more slowly.

Every sensory channel can become less sensitive as individuals age. For example, reduced fine motor control makes cellular telephone buttons and keys difficult to manipulate, a problem that is compounded for those with arthritis of the fingers. Research looking at the usability of several alternatives—touch screens, larger keyboards, and voice input—has found that touch screens are the easiest for elderly persons to use and can enable older adults to achieve performance comparable to that of younger adults. However, these solutions can present their own challenges, including accidental activation and arm fatigue.

Declines in vision can also impair effective response to warnings and alerts in older adults. Older adults generally have greater susceptibility to glare and difficulty distinguishing between certain colors, for example, blue and green. For CMAS and mobile devices, text for older persons needs to be made more readable through the use of 12- or 14-point, sans serif fonts and the avoidance of colors that are difficult to distinguish between. Older adults also tend to have difficulty hearing higher frequencies. As discussed earlier, most ring tones are in the higher frequencies, and this could prevent older adults from hearing the alerts. The preference of a particular vibratory cadence may differ by age.

In addition to an increase in visual and auditory disabilities or impairments that often occurs in older persons, there are comorbidities associated with age. Older adults thus often face multiple hindrances in receiving and responding to alerts and warnings delivered by mobile devices.

There are also significant challenges for those with diminished cognitive abilities. Steps such as comprehending an alert, seeking additional information, and deciding on an appropriate decision to take protective action rely heavily on cognitive abilities such as attention and memory.


U.S. Census Bureau, “U.S. Interim Projections by Age, Sex, Race, and Hispanic Origin.” Washington, D.C., 2004.

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