Continuity and Change in the Computer era 205
necessarily mean that a map is more effective.
As with all map forms, looking at
many examples helps the cartographer develop an “eye” for good maps.
Unfortunately, a book is limited to static maps; animated maps cannot be shown.
A few websites are listed in Appendix B. Entering “animated maps” or “cartographic
animation” in a web browser will result in hundreds of examples that can be viewed
and evaluated.
soUnd mAPs
Sound is usually combined with sight, touch, or both in specialized maps. Sound has
the potential for being a valuable addition to maps for the visually impaired, but it
can also be useful on maps for sighted readers. Sound can be used in a variety of ways
on electronic maps. It can be used as (1) narrative—to identify features and describe
them, common for animated maps and automobile GPS units; (2) as a memetic (real-
istic) symbol on a map, such as a car horn, bomb blast, or dog barking, analogous to
pictorial symbols in vision; (3) as a redundant variable, such as a spoken name plus a
written label; (4) instead of visual patterns; (5) as an alarm; (6) for adding nonvisual
data dimensions; and (7) to reduce visual distraction or clutter by replacing labels, or
by representing location.
Like visual symbols, sound can be realistic or abstract. Voice narration is the
most obvious and probably most common sound used on maps. Other sounds rep-
resent
real-world sounds, such as horns,
doors closing, and the like.
Abstract sounds
can be cues or can represent data. John Krygier (1994) has proposed a basic set of
elements of sound and has created a table of “sound variables” analogous to visual
variables (Table 11.1). These variables are location, loudness, pitch, register, timbre,
duration, rate of change, order, and attack/decay. Just as visual variables are used for
qualitative (nominal) and quantitative (ordinal, interval) data, sound variables can
represent data.
