||For interaction, InTheMix utilizes two natural inputs: head-position
and vocal signals. A participant may position his or her head in the space in the normal
physical ways: walking, leaning, twisting, crouching, or crawling. The listener
is allowed to roam a physical free range of up to a 4-meter radius. If a
participant is motionless, voices and sound effects coax them to move. The content
density is proportional to user movement. When the participant turns, faces,
and approaches a sound, InTheMix assumes the participant is taking an interest
in the sound and enhances it with more tracks. If the listener ventures past the
edge of the virtual space, voices and sounds encourage them to return. While voice
is primarily used for inter-participant communication in a multi-node configuration, the
InTheMix team is experimenting with the interpretation of user excitement through
analysis of the microphone signal.
InTheMix is most effective to visually-dominant participants when blindfolded.
Blindfolding or a darkened room may be employed. While InTheMix is compelling as a single node, the use of multiple nodes to allow participants to share
their experience can be really fun. These nodes may be remotely located to promote
the tele-virtual experience; or adjacently located for participant convenience.
Siggraph 2000 features three InTheMix nodes: two adjacent, one remote.
The InTheMix content is designed for a two to three minute experience.
While there are psycho-acoustic reasons for encouraging longer experiences (five minutes),
the design for shorter experiences allows for more participation. Some hurried
participants may be satisfied in less than a minute. The aural experiences of each
of the participants may be replicated for non-interactive, side-line listeners through
a bank of headphones. InTheMix is about hearing more than feeling
and looking. InTheMix is entirely displayed over headphones.
The sound space is split into zones as shown in the spatial scheme
. Each zone will feature a different genre of music. While the aural
environment is based on a physical model, the zones must be separated by virtual distance
so sound from other zones is naturally attenuated. At the same time, the real physical
space is small, allowing the listener to easily roam from one zone to another. This is
accomplished by employing a "hyperspace" between zones. Think of InTheMix as three bandshells in a park, but the listener's traversal across the park is accelerated.
Physically, there may be a circle on the carpet to allow on-lookers to understand the bounds
of the unseen virtual space. Otherwise, an InTheMix node is simply a
pair of headphones cabled above. Evidence of equipment such as computers and tracking
instrumentation is minimized. The tracking transmitter is mounted above the circle,
while a computer pedestal is off to the side.