The Voice Tracker™ I Array Microphone was the original implementation of our patented, automatically and electronically steering, “listening beam” technology. It has been in production since 2002, and has proven to be extremely rugged and reliable.

The Voice Tracker™ I Array Microphone was designed with two objectives. The first was to provide coverage throughout a large room for recording or conferencing applications to eliminate the need for multiple microphone/mixer setups, which require expert installation and are expensive. The second was to provide high quality audio for automatic speech recognition without the encumbrance of wearing a head set mic or holding a handheld mic.

Pick up over an entire room is accomplished in two ways. First, sensitivity was increased compared to conventional microphones by constructively adding the output of eight separate always on microphone elements. Second, spatial filtering and background noise reduction are used to eliminate sound from all areas in the room except that space around the active talker, so the increased sensitivity is not corrupted by noise.

As a consequence, the Voice Tracker™ I Array Microphone can pick up talkers at ranges of 30+ feet in meeting/classroom recording or conventional conferencing applications. It can work effectively for command control automatic speech recognition application at the same distances, and full vocabulary ASR at ranges of a few feet.
The Voice Tracker™ I Array Microphone has an analog audio output at mic level, and is powered by a wall power converter so there is no risk of loss of performance as batteries run out. A USB adapter is an available option for use with MACs, and laptops with low performance sound cards.
The Voice Tracker™ I Array Microphone has a built in ceiling mount capability, which removes the clutter of mics on the conference table.
The Voice Tracker™ I Array Microphone can be used in conventional conferencing systems that have AEC. The Voice Tracker™ II Array Microphone was designed for use with VoIP conferencing systems that need the AEC built in to the microphone itself.

Voice Tracker™ I Features

• Automatic electronic steering of "listening beam" to talker location
• Selectable steering limits (90 degrees and 180 degrees) for speech recognition and Meeting recording modes
• Selectable LDS™ to reduce annoying interference of additional talkers during speech recognition or feedback during teleconferencing
• Two stage noise reduction (spatial filtering and noise reduction processing)
• 8 element, 18 inch long array for maximum range
• 5 element "in range" light to indicate location of chosen talker and sufficiency of signal
• Microphone tilt capability to facilitate desktop, monitor top, ceiling, or wall mounting
• Weight: 1.5 pounds(excluding wall power supply)
• Power: converter from 120V AC to 6V DC included
• Compatible with a variety of operating systems including:

Voice Tracker™ I Specifications

 Range:

• 30+ feet for meeting recording (depends on acoustic characteristics of the room.)

Analog Output: (6ft male/male audio cable included)

• Mic level
• 3.5mm ministereo jack
• Same signal on tip & ring
• 500 ohm output impedance
• Frequency Response:
• 100Hz to 11,250 Hz 

Physical Dimensions:

• Length: 18"
• Height: 2.5"
• Weight: 2.5lbs

Power Equipment: (wall-powered converter included)

• 6V DC
• 400 ma
• Center Pin Positive

Since the Voice Tracker array microphone can pick up talker throughout the entire room, it has often been used for conferencing applications

It became clear from customer feedback that incorporation of a high-quality acoustic echo cancellation (AEC) algorithm would broaden the Voice Tracker's application by enabling full duplex VoIP based conferencing at a fraction of the cost of conventional conferencing systems.

The addition of a high-quality AEC algorithm to our internal DSP is the main differentiating feature of the Voice Tracker II ™ Array Microphone, but it has several other attributes as well.

Turns inexpensive VoIP based telephony systems like Skype and Adobe Connect into Conferencing tools.

A crucial audio requirement for conferencing is the elimination of acoustic echo (sound from the far end talker picked up by the open mic and sent back). The Voice Tracker II ™ Array Microphone’s internal AEC algorithm provides performance that rivals or exceeds that of AEC boxes costing several thousand dollars. Connect the Voice Tracker II ™ Array Microphone to your PC based VoIP software and eliminate the need to use headphones; all the near end talkers will be heard, even if they talk softly or are far away from the mic, and the far end talker will hear no echo. 

Audio Spectrums for AECAcoustic Echo occurs when an open mic picks up a far end talker (from the loudspeaker) and sends it back to the far end talker (as an echo). In the above charts, the bottom chart shows the audio from near end and far end talkers transmitted by the Voice Tracker II with acoustic echo cancellation off. The top chart shows a similar audio transmission with the AEC turned on. Output recording of the Voice Tracker II with AEC off. Output recording of the Voice Tracker II with AEC on 

 Improved Portability

The Voice Tracker II™ is significantly smaller than the Voice Tracker I. The Voice Tracker II’s primary audio output is USB and it is powered by its USB connection, eliminating the need to be connected to wall power. Not only does this remove the need to carry the wall power converter, it eliminates the need to have different wall power converters for different countries.

Talker Location Signal

Since the Voice Tracker automatically and electronically steers a listening beam to the active talker, it knows the location of the talker. In the Voice Tracker II ™ this information is made available outside the DSP as a RS 232 serial word through a DB-9 Jack. A sophisticated customer can use this information to point a camera, or turn the head of a robot toward the talker. Note that Acoustic Magic does not provide any algorithms for the use of the location information.

 Voice Tracker II™ Features

• Automatic electronic steering of "listening beam" to talker location
• Two stage noise reduction (spatial filtering and noise reduction processing)
• Built in High Quality Acoustic Echo Cancellation.
• 6 element, 10 inch long mic array for long range
• Mute Mode
• 5 element "in range" light to indicate location of chosen talker and sufficiency of signal
• Talker location signal thru DB 9 jack (cable optional)
• Compatible with a variety of operating systems including: 
• Apple/Macintosh : Mac OS, Mac OS X 
• Microsoft : Windows 3.x, Windows 95,Windows 98,Windows NT, Windows 2000,Windows ME, Windows XP, Windows Vista, Windows 7

 Voice Tracker II™ Specifications:

Range: 

• 20+ feet for meeting recording (depends on acoustic characteristics of the room).

AEC Performance: 

• G.167 Compliant
• 70 db of echo cancellation in single talk
• 40 db of echo cancellation in double talk
• Convergence time of less than 100ms
• Sample rate: 48KHz

Primary audio output: USB

Secondary audio output: 

• Mic level or Line level (switch controlled) 3.5mm ministereo jack
• 6ft male/male audio cable (optional) Same signal on tip & ring 500 ohm output impedance

Talker location signal accuracy: 5 degrees

Frequency Response:

• 100Hz to 11,250 Hz

Physical Dimensions:

• Length: 11.5"
• Height: 1.5"
• Weight: 0.75lbs

Power Equipment: 

• Powered by USB (wall-powered converter optional)
• 5V DC
• 400 ma