Acoustic Magic Voice Tracker User manual

INSTRUCTIONS
General Setup
Connect the power and audio cables to their appropriate
jacks on the back of the Voice TrackerTM Array (see
Figure 1). Plug the power adapter into a standard 110
volt wall outlet and connect the other end of the audio
cable to the “Line In” input on your computer’s sound
card. The adapter supplies 6V DC power to the
microphone.
Figure 1 – Audio and Power Cable Connections
The Voice TrackerTM Array may be used as the audio
input device for a variety of speech and multi-media
applications. Many of the software packages which
utilize a speech input have setup tools which allow you
to specify that you are using the “Line In” connection on
your soundcard and to adjust the sound level (volume)
automatically. Please refer to your specific application
software for details. To adjust the volume or input
selection manually on a Windows PC, see the Adjusting
Your Soundcard section at the end of these
instructions.
Positioning
Aim the array in the direction of the desired talker(s).
When properly positioned, the talker will be able to see
all 5 green position indicators (see Figure 2).
Figure 2 – Voice TrackerTM Array Front View
The Voice TrackerTM can be tilted up or down to facilitate
mounting on the desktop (tilted up) or on the monitor
(tilted down). For speech recognition applications, the
desktop position will exhibit slightly better performance.
If you mount it on top of the monitor, makes sure it is
secured so it doesn’t fall off.
Mode Switches
The Voice TrackerTM has 4 operational modes, selected
by two switches: the Field switch and the Location
Dependent SquelchTM (LDSTM) switch (see Figure 3).
Figure 3 – Field and LDSTM Switches
The Field switch determines the scanning range of the
array. In the wide-angle mode, the Voice TrackerTM will
scan +/- 90 degrees. This is useful if the user desires to
listen to an entire room. In the narrow-angle mode, the
array will scan +/- 45 degrees. The narrower scanning
range helps to reduce the impact of undesired talkers
and noise sources outside the region of interest.
When the LDSTM switch is set to On, the Voice TrackerTM
will turn off during periods of silence and when the sound
source is located outside the array’s reception region as
determined by the Field switch. The array turns on
again very quickly when the user resumes talking.
When used together with the narrow field of view, the
LDSTM can be employed to ignore unwanted sounds.
Once the talker pauses and the Voice TrackerTM turns
off, the array will only turn on again when sounds come
from within the +/- 45 degree listening area (see Figure
4).
Figure 4 – Listening Area
For speech recognition applications, when the limited
scan range and LDSTM are on, the generation of
spurious words or commands from sources outside the
listening area will be reduced. The user should decide
whether this feature improves performance in their
particular noise environment.
Using a narrow field of view and LDSTM can also be
useful when teleconferencing. If the incoming talker’s
speech is played through loudspeakers positioned
outside the +/- 45 degree listening area, the array will
turn off when only the far-end talker is active, thereby
minimizing echo in the channel.

Position Lights
The green position lights provide feedback on the
operation of the array. They indicate where the array’s
listening beam is pointing. When the array recognizes a
relevant sound, one of the 5 lights will be illuminated.
The individual lights correspond to the range of potential
sound source locations. For example, if a talker is
directly in front of the array, the middle light will be
illuminated. If the talker is to one side, a light on that side
will turn on. If the talker moves across the field of view of
the array, the lights will track the talker’s motion. When
two users are sharing the array, the light will indicate the
direction of the active talker. In the narrow scanning
range mode, only three lights are active. When there is
no active talker, the lights may flicker as the Voice
TrackerTM searches for a talker.
When the LDSTM
is on, the indicator light will be
illuminated only when there is sound activity within the
designated listening area. With the LDSTM off, a light will
remain on continuously through both speech and silence
periods. In the event that no lights are on and the
LDSTM mode is off, it is possible that the array is not
plugged in or is working improperly.
Using the Voice Tracker for Speech Recognition
Since the Voice TrackerTM operates differently from other
types of microphones or audio input devices, you should
retrain your speech recognition system after connecting
the array and adjusting the soundcard gain level. This
will allow you to more effectively utilize the improved
sound quality produced by the Voice TrackerTM and will
improve the overall performance of your speech
recognition software. Personalized vocabulary can
usually be transferred to the retrained “User”.
Adjusting Your Soundcard
On your Windows PC:
1. Go to Start button, Programs, Accessories,
Multimedia (or Entertainment), then volume control.
2. Make sure the Line In’s mute is checked.
3. Go to Options, then Properties, select the circle next
to Recording.
4. In the ‘Show Volume Controls’ region check the box
next to Line In and then click OK.
5. Check the Select box under Line In and set its
volume to an appropriate level for your soundcard.
Be careful not to set this volume level too high. This
will cause clipping.
6. Exit recording control.
If your sound card does not have sufficient gain or if your
speech signal is too soft, using the Microphone In
instead of Line In Input on your soundcard may correct
this problem. Switch the audio cable on your soundcard
from Line in to Mic and follow these instructions to
change the audio input selection and gain on your
Windows PC:
1. Go to Start button, Programs, Accessories,
Multimedia (or Entertainment), then Volume Control.
2. Make sure the Microphone’s mute is checked.
3. Go to Options, then Properties, select the circle next
to Recording.
4. In the ‘Show Volume Controls’ region check the box
next to Microphone and then click OK.
5. Check the Select box under Microphone and set its
volume to an appropriate level for your soundcard.
Again, be careful not to set this volume level too
high.
6. Exit Recording control.
FCC Compliance
This equipment has been tested and found to comply the
limits for a Class A digital device, pursuant to part 15 of
the FCC rules. These limits are designed to provide
reasonable protection against interference when the
equipment is operated in a commercial environment.
This unit generates, uses and can radiate radio
frequency energy, and if not installed and used in
accordance with the instruction manual, may cause
harmful interference with radio communications.
Changes or modifications not expressly approved by
Acoustic Magic could void the user’s authority to operate
the equipment.
This digital apparatus does not exceed the Class A limits
for radio noise emissions from digital apparatus as set
out in the Radio Interference Regulations of the
Canadian Department of Communications.
If you have further questions, e-mail us at
[email protected]
or call 978 440 9384.
ACOUSTIC MAGIC, INC.
35 Peakham Road
Sudbury, MA 01776
www.ACOUSTICMAGIC.com