
DA-300
tm
AutoArray
Digital Automobile Microphone
®
DIGITAL SUPER DIRECTIONAL ARRAY TECHNOLOGY
Product Overview
The Andrea DA-300
patented Digital Super Directional Array (DSDA
and communication. The Andrea
specifically for the natural speech interface of Auto PCs, global positioning systems (GPS) and cellular
car phone kits. The Andrea
and a Digital Signal Processor (DSP). The
dashboard and is unobtrusive to the drivers vision. DSDA technology's unique software algorithms
combine and focus multiple acoustic signals received from the microphones. The result of the system's
processing is an exceptionally clear voice signal from the driver into the speech enhanced device,
assuring the highest speech recognition accuracy and performance in the challenging environment of invehicle computing. (See Figure 1).
AutoArray
AutoArray
™ is a revolutionary digital, multiple microphone system that incorporates
AutoArray
consists of a series of microphones, unique software algorithms
®
) technology for enhancing voice for in-vehicle computing
is the first super-directional audio input device designed
AutoArray
attaches to the car visor, the windshield frame or
Technology Overview
A key to the exceptional performance of the
on and enhance desired acoustic signals, specifically the driver's voice, and eliminate ambient noise.
DSDA technology's ability to center microphone sensitivity in one focused direction reduces noise from
all other sources. The array constantly samples the acoustic environment, adaptively identifying
interfering noises that are extraneous to the speaker's voice. These ambient noise sources are then
reduced, resulting in improved signal-to-noise ratio of typically 30dB and, hence, enhances intelligibility.
(See Figure 2 and Figure 3).
The In-vehicle Computing Experience
The Andrea DA-300
recognition performance, even in the noisiest vehicle environments, where the engine, air conditioning,
wind, traffic, passengers' conversations and the radio can corrupt speech intelligibility.
AutoArray
offers automobile users optimized voice input clarity for speech
AutoArray
microphone is DSDA technology's ability to focus
Freedom of Voice™

Andrea AutoArray™ : An illustration of microphone performance
-20
Adaptive
Digital Signal
Mic
Array
Processing
Clean Speech Output
Noise Signal
Noisy Voice Signal
Summed Signals
Eliminate Noise
Inverted Anti Noise
Noise Signal
Signal
Figure 1. DSDA Illustration
Proven T est Results
As part of a recent series of Auto PC tests, comparative microphone tests between the Andrea
and a standard directional microphone used in the automotive industry were performed. 28 verbal
commands were spoken to the Auto PC using both the
Under the most rigorous road test conditions, as illustrated in Figure 4, Test 3; the Auto PC experienced a
93.3% recognition rate using the Andrea
AutoArray
compared to a 0% recognition rate using the
standard directional microphone.
-25
-30
-35
-40
-45
-50
-55
dBV
-60
-65
-70
-75
-80
-85
-90
-95
-100
0 500 1k 1.5k 2k 2.5k 3k 3.5k
Hz
4k
Figure 2.
Voice Frequency Response @ 0˚ vs.
Background Noise Response @ 45˚ and 90˚
AutoArray
and a standard directional microphone.
0˚
45˚
90˚
4.5k 5k
AutoArray
0˚
1000
30˚
0
30˚
5
60˚
10
15
60˚
20
25
90˚
120˚
150˚
150˚
180˚
90˚
120˚
*Green represents
voice signal
Figure 3.
Polar Plot of Directional Microphone Sensitivity Beam
(1/3 Octave Noise, Centered at 1 kHz)
Radio
Microphone
Description
Nomad
Start
Mute
Volu me
Help
Next
Previous
Radio
Disc Player
Navigate
Address Book
Setup
Audio
AM
FM
Preset
Stop
Review
Zero
One
Two
Three
Four
Five
Six
Seven
Eight
Nine
Test #1
Competitor Andrea Array Competitor Andrea Array Competitor
Automobile
Automobile
Score Score# Tries
59
55
61
61
68
60
71
70
79
70
66
52
68
66
57
69
60
75
72
65
63
53
59
72
79
54
58
72
64.8
Radio On,
Radio On,
Window
Window
Partial
Partial
# Tries
71
1
1
62
1
1
63
1
1
70
1
1
59
1
1
55
1
1
71
1
1
70
1
1
79
1
1
72
1
1
69
2
1
70
1
1
83
1
1
73
1
1
62
1
1
71
1
1
57
1
1
74
2
1
69
1
1
73
1
1
61
1
1
65
1
1
60
1
1
75
1
1
74
1
1
51
1
1
60
3
2
74
1
1
67.6 60.9 67.7 0 65.7
87.50% 96.60% 49.10% 82.40% 0.00% 93.30%
Automobile
Radio Loud,
Window
Down
# Tries # Tries
Score
3
66
2
50
3
58
4
56
2
50
1
61
1
67
5
71
2
73
1
62
2
51
2
53
1
65
1
57
6
69
1
63
1
58
2
76
3
58
1
65
1
62
1
67
4
55
1
70
1
63
1
54
3
50
1
54
Test #2
Radio Loud,
Score
57
58
66
60
67
63
70
71
79
71
60
68
69
69
52
66
59
79
74
72
69
73
57
74
83
72
72
65
Automobile
Window
Figure 4.
™
Down
Test #3
Automobile
Radio Loud,
Both Windows
Down
Score
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
4
no recognition
1
no recognition
1
no recognition
2
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
1
no recognition
3
no recognition
Andrea Array
Automobile
Radio Loud,
Both Windows
Score
68
54
69
68
63
66
70
74
70
66
52
81
65
64
72
52
75
62
70
64
56
60
73
80
64
70
56
56
Down
# Tries
1
1
1
1
1
1
1
1
1
1
1
1
1
3
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Andrea Electronics Corporation
Andrea Electronics Corporation
45 Melville Park Road, Melville, New York 11747
45 Melville Park Road, Melville, New York 11747
www.AndreaElectronics.com
www.AndreaElectronics.com
Phone/Fax: (800) 442-7787
Phone/Fax: (800) 442-7787