Hello, my name is Stine Johansen, and I'm happy to present our paper Investigating
Potentials of Shape-Changing Displays for Sound Zones on behalf of myself and my co-authors.
I want to start by briefly describing what a sound zone is
and the motivation behind investigating ways of supporting how we interact with them.
Betlehem et al. defines a sound zone as a defined area in which the volume of a particular sound is
increased while simultaneously decreasing it in other areas. This enables different
users to listen to different sounds within the same room without disturbing each other
such as the two persons in the right side of this illustration. Previous
research has outlined different challenges for designing interaction with sound zones,
and this includes the fact that sound zone systems have different spatial properties than other
current speaker systems. They have a position from which the optimal listening experience can be had,
and ideally the user should be very close to this position to not be disturbed by other sound zones.
Like other speaker systems, the volume can be turned up and down.
Sound zones have a size which can be narrowed or expanded, and they can overlap. For example,
if the size of one sound zone is expanded into another sound zone. So this means that
the person in the small sound zone is now disturbed by the sound from the big zone.
We focus on shape-changing visualisations for two reasons. First, expressing information
through a physical shape can fulfil aesthetic goals in addition to functional. Second,
mechanical movements and shape-changing features are increasingly integrated into speaker systems.
Neither of these examples here, however, carry information about the sound. So inspired by this,
we suggest that dynamic movements and shapes could be designed for informational purposes
in relation to interaction with sound zones. And as a first step towards this, we focus on how such
physical shapes are experienced visually. And we constrain our design to fit a sound bar.
To develop types of shapes and connect movements to specific interactions, we conducted a design
session with 12 experts with experience with sound zone systems. From sketching sessions, we defined
four basic shapes shown to the left in this slide. We also defined four ways of displaying
overlapping sound zones and two types of movement: Vertical which we hypothesise would be useful for
displaying volume changes, and horizontal movement for displaying position changes.
A final takeaway from the session was that volume and size properties should be
considered as one since when you increase the volume, you also increase the sound zone area.
To evaluate these basic shapes and movements, we constructed a prototype using motorised actuation.
The scale and resolution of the display was determined by the size of the room of the study,
the resolution of the sound zone system, and constraints set by the mechanical solution.
This resulted in a prototype with 48 individually moving pins
with a vertical displacement of 10 centimeters per pin. The prototype consists of 12 modules, each
with 4 motorized potentiometers. These 4 potentiometers are controlled by an Arduino
Nano which is connected to a central Arduino Mega. As shown in this slide, we could now display the
basic shapes and movements defined previously. The study took place in a lab with two active sound
zones where we recorded both video and audio. We placed two controllers in front of participants
which controlled the position and volume of one of the sound zones. We used an ultra-wideband
positioning tag to determine the position of the sound zone and a rotary potentiometer for volume.
We recruited 17 participants with no prior experience with sound zone systems. We then
started each trial with a non-verbal introduction to the sound zone system by letting participants
explore the space. Then, we introduced each participant to a shape and movement,
and we asked them to perform an interaction that would match the visualisation using either the
volume or the position controller. In a third phase, we asked participants to freely explore
shapes and movements through interacting with the controllers,
and finally we conducted debrief interviews. Analysing the collected data, we counted
participants' choices in the elicitation phase, and we conducted an inductive thematic analysis
of the video and audio material. And I'll present four themes emerging from this analysis.
First of all, our findings from the elicitation phase showed
that participants clearly related horizontal movements to position changes and vertical
movement to volume changes. Five participants were not consistent at the outset of the trials,
but four of them began to choose consistently after the first half of the shapes were shown.
Then, we found that participants expected the sound zone to have different properties
according to different shapes. For the curve shape, for example, they expected the sound
to fade slowly from the center of the zone, but for block shapes, they expected the sound to be
very contained in a more clearly defined area. When the display was divided into two sections,
14 participants expected the sound of each zone to distribute equally out in the visualised area.
And the single pin was experienced as relating directly to the user, and as such they didn't
expect for example to be able to share the sound zone with a different person.
For patterns relating to overlapping sound zones, we found that participants were confused
when the shape included a border between two curves. Some described it as a third zone.
We also found that some participants positioned themselves further away from the static sound zone
when the border pin was included as can be seen on this slide. For the fourth theme,
we found that participants generally mapped the width of the display to the width of the room.
However, in two instances, participants chose to position themselves in a 90 degree angle
from the display and that limited the movement to only be within the width of the display.
Our paper contributes with two key takeaways. First, our elicitation study
shows that participants relate the experience of sound zones to other experiences with sound,
and that means that in several cases, the sound zone system behaved in a way that contradicted
their experiences. The distinctions made in our design session with experts were not as clear
to participants with no prior experience with such systems. So this for example relates to
the distinction between a sound zone and a sound source, and that wasn't made by participants. And
that emphasises that designing interaction with sound zone systems should be viewed as
designing interaction with the sound itself together with the spatial properties. Second,
we gather our findings of shape and movement experiences in the illustration showed here.
We found that it matters what shapes we use to visualise the sound zones, and this can
be elaborated in two dimensions that relates to how much information a shape carries and
whether or not this information is visualised in a concrete or in an abstract manner. For example,
two curves provide more information than two block shapes, but both are concrete visualisations
of the sound zones. The single pins, on the other hand, offer more abstract information
by representing the user indirectly. So with these key takeaways, I would like to say thank you for
watching this presentation, and please feel free to reach out for further questions or discussions