|
|
HEARING |
|
|---|---|---|
| Hearing Acuity | 1. Use adaptive volume controls. | |
Inability
to
hear
|
Provide for control of sound by user in order to ensure that the loudness level can accommodate all users regardless of their sensitivity. When the impact of the comunication is critical, relate the volume of sound to the urgency of the cue, and provide both visual and audio cuing. Minimize the ambient sound produced by the product or the enviroment so that confusing audio signals are eliminated. |
|
| Frequency Discrimination |
Provide mid-range and/or modulated sound indicators. | |
Inability
to hear
|
Keep all sound indicators in the mid-range frequencies to avoid problems associated with both the high and low fequency ranges. If full-range sound indicators must be offered, provide the user with sound modulating devices. Provide sound that is in distinct contrast to the sound environment (e.g., voice indicator for non-voice environments; non-voice indicator for voice environments). When sound is used, relate the "friendliness" of the sound to the urgency of the alarm (e.g., the greater the urgency, the less friendly the sound). |
|
Speech Discrimination & Comprehension |
1. Minimize the use of problem consonants. | |
| Inability
to distinguish
certain
consonants
(c, ch, f, s, sh, and z). |
As far as practicable, avoid using such problem consonents as "c", "ch", "f", "s", "sh", and "z." If such consonants must be used, emphasize correct diction and enunciation in the voice messages. | |
| 2. Filter out background noise. | ||
| Ambient background noise exacerbates the problem of distinguishing problem consonants. Therefore, provide for means to keep word messages at lest 10 db above the ambient noise level. Redundant visual cuing will help ensure communication in case the audio message fails . | ||
3. Reduce
the speed
of voice
messages |
||
Rapid
speech becomes
hard to understand. |
Consider the clarity of the voice cue by presenting speech messages with deliberation. Emphasize clear and proper enunciation, and consider the environmental background noise. | |
Directional Hearing |
1. Avoid excessive use of sound for communication purposes. | |
| Confusion
about the
direction
or source
of sounds. |
In applications where it is necessary or desirable to help locate the source of the sound, combine a visual device with sound, preferable at the source. Where sound is used to communicate different functions, differentiate each function through the use of a different sound. | |
| 2. Provide appropriate audio messages when sound is essential. | ||
| Use clear and unambiguous sound cues for critical information or warnings. When voice messages are necessary, use an attention-getting sound prior to the voice message. Wherever practicable, focus the sound message toward user and design the product and its environment to minimize the sound's deflection. | ||
| 3. Provide appropriate audio messages when sound is desireable. | ||
| Back to Top | Sound messages are desirable and appropriate when:
|
|
|
||
Rationalizations
can no
longer
excuse
designs
of products
or environments
that fail
to attract
and accommodate
any segment
of the
population.
*Courtesy of "Guidelines and Strategies for Designing Transgenerational Products," was suported, in part, by Grant number 90-AT-0182, from the Administration OIffice of Human Development Services, Department of Health and Human Services, Washington, DC 20201, and the All-University Gerontology Center, Syracuse University.
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