Information Technology Reference
In-Depth Information
- the pitch slot is constant (two octaves); the pitch gap between two consecutive
items therefore depends on a number of items.
Design 2
= double tone:
- same beep as for a
single tone
followed by a beep corresponding to the first
item on the list (if scrolling up) or last item on the list (if scrolling down).
Design 3
= proportional regrouping:
- a single beep before the vocal synthesis (same as design 1);
- only eight notes used (C, D, E, F, G, A, B, C - starting from C4
7
);
- if there are only eight items, there is one note per item;
- if there are more than eight items, there is a grouping together, one note for
each group of N/8 items. If N is not a multiple of eight, the last group takes the rest.
This design makes it possible to have an idea of the size of the menu after
scrolling the first items.
Design 4
= alphabetical regrouping:
- only for the lists classed alphabetically;
- maximum of 26 notes, one note for each letter of the alphabet. For example: all
the items beginning with A are indicated by the same note.
A comparison of these four different designs is carried out thanks to preference
tests and the results are presented in section 8.5.4.4.
8.3.2.
Sound representation of the semantic content
8.3.2.1.
Vocal synthesis
An initial approach to representing the semantic content of an item in a menu
thanks to a sound consists of saying the word, whether by vocal synthesis (
Text To
Speech
or
TTS
) or by a recording from a speaker. This approach is largely used in
the case of systems destined for people who are blind or who have impaired vision.
This principle is also used in a project called
earPod
[ZHA 07], targeting a
system to aid scrolling for a portable music player (like an iPod): the user scrolls
7 C4 represents the 4
th
note of C on a standard piano keyboard.
