Information Technology Reference
In-Depth Information
down items in the menu by sliding his finger on a circular
trackpad
8
, and each
element is announced by vocal synthesis.
This approach has the advantage of not requiring any learning, but it does have
one limitation: the listener must know the language used for the enunciation of the
word.
8.3.2.2.
“Spearcons” (speech earcons)
This notion was introduced by Walker [WAL 06] in order to compensate for the
limitations of a sonification based on earcons or auditory icons (see section 8.3.3).
Among these limitations, the author mentions for example the arbitrary side of the
earcon/item relationship, which requires an explicit learning, and the rigidity of this
system as it is difficult to carry out changes in the hierarchy once it has been
sonified.
The
spearcon
associated with a menu item is then obtained in the following
manner. The item is first of all announced by vocal synthesis; then it is modified by
time stretch
, with conservation of the pitch of the original word. The rate of time
stretch is not fixed
a priori
; it is chosen according to the length of the original word
and the level of intelligibility that we wish to keep. Indeed, the spearcon is not
necessarily recognizable as a word.
A spearcon thus represents an item in a unique manner as it is made from the
word of the item, and the similarities between the items are translated by similarities
between spearcons. For example, the three items “save”, “save as”, “save as web
page” will be associated with similar spearcons as they all start with the same word.
The results of the evaluation are satisfactory (see section 8.5.4.3), as a spearcon only
needs to be listened to once on average in order to be learned.
8.3.2.3.
Auditory icons
The notion of auditory icons was introduced by Gaver [GAV 86] to describe a
sound that represents an object (or an action) by referring to a sound in our
environment. In some cases, the sound can be directly linked to the object or the
action (e.g. the
Camera
item is represented by the sound of a clicking shutter). But
in most cases a metaphorical link is established between the sound and the object
that it represents: for example, a sound of paper being thrown into the bin means the
deletion of a file on a computer. In contrast to earcons, auditory icons require very
little learning as they refer to sounds known to all.
8 http://www.dgp.toronto.edu/~sszhao/earPod.html.