Game Development Reference
games a player gets a mental picture of all pres-
ent objects and persons by listening to the sounds
which characterize them. Stereo positioning is
used to spatially distinguish the sounds of objects.
It allows the sound to traverse from left to right,
and vice versa. These sounds are critical for the
player and his/her understanding of the game.
Yet stereo positioning only gives the player one
dimension, which is a constraint compared to the
two dimensions of a screen.
On the other hand, binaural localization with
four or five channels produces a feeling of being
surrounded by a unique sound field. This occurs
because every channel conveys different informa-
tion, a different form of sound, so the user has a
sensation of sound coming from one direction.
Although this form of audio spatial presentation
is paramount, it is most commonly not accessible
for visually impaired users because of financial
or other reasons.
In the following sections, some experience in
design, implementation, and validation of several
education games for the visually impaired is
The basic problem while developing the mem-
ory game was to enable binaural two-dimensional
localization of objects, one that would allow visu-
ally impaired players a quick, suitable response.
The problem would be solved more easily if the
solution employed more than two sound channels,
but as most visually impaired users only have or-
dinary headphones, a two channel solution had to
be found. Based on the characteristics of binaural
hearing the authors have decided to present the
horizontal position of the field by simple stereo
presentation (different interaural levels between
ears), and to indicate the vertical position of the
field by using different audio frequencies (pitch
of the synthesized speech) (Gärdenfors, 2003;
Delić & Vujnović-Sedlar, 2010).
Following the example of ancient Chinese Tan-
gram, Lugram is designed as a puzzle game based
on composing a given geometric figure (Lučić &
Vujnović-Sedlar, 2009). Elements to be used for
assembling are square tiles containing geometric
figures: triangles, rectangles or squares, as shown
in Figure 1.
The principles of Lugram are in line with the
curriculum and the level of geometric education
in primary schools, thus helping the formation of
a solid basis in the initial learning of geometry.
As it is a multimedia, interactive game, sup-
ported by a database allowing adaptation for
different user needs, and as it has different com-
plexity levels, it can be adapted to the age of the
targeted pupils. Bringing practical work through
problem solving exercises, the game is successful
in providing a motivation factor in learning ge-
Lugram is a set of very simple geometric
puzzles, therefore, it is possible to adjust it to
the people with disabilities. One direction of the
development of the game led to a successful ad-
aptation for visually impaired users (Lučić et al.,
2009), and opened the perspective for a special
The first memory game intended for the visually
impaired using speech technologies in Serbian
(Delić & Vujnović-Sedlar, 2010), introduces visu-
ally impaired children to working with computers
and speech technologies, while it also stimulates
the development of motor skills and represents
a step towards better socialization. It is a simple
and well-known memory game with sixteen fields
hiding eight pairs of objects. The goal of the game
is to locate pairs of objects, with a speech syn-
thesizer naming every object in such a way that
determining its position on a four-by-four board
is facilitated by way of binaural localization. The
user has two options - to select the square using
verbal commands (by pronouncing the coordinates
of the square), or simply to use the keyboard.