Table 7 The result of recognition when one machine plays MIDI files with a loudspeaker and another machine picks up the sound and tries to recognize it using Bideyuanli (the average decibels d1 measured at the loudspeaker remain unchanged, the average decibels d2 measured at the pickup change, and the background noise is d3 decibels) Let t1 = m/n, if a URL has n characters and m characters are recognized correctly, as well as t2 = d2-d3.
From: A novel approach for audible acoustic quick response codes
MIDI file | Value of t1 \ t2 (scenario 1) (The distance between the two machines is 1 m and there is no obstacle between them) | Value of t1 \ t2 (scenario 2) (The distance between the two machines is 3 m and there is no obstacle between them) | Value of t1 \ t2 (scenario 3) (The distance between the two machines is 5 m and there is one wall between them) | Value of t1 \ t2 (scenario 4) (The distance between the two machines is 10 m and there is two walls between them) |
|---|---|---|---|---|
a1.mid | 1 \ 43 | 1 \ 31 | 1 \ 27 | 0.60 \ 13 |
a2.mid | 1 \ 46 | 1 \ 35 | 1 \ 25 | 0.60 \ 16 |
a3.mid | 1 \ 42 | 1 \ 33 | 1 \ 25 | 0.70 \ 23 |
a4.mid | 1 \ 45 | 1 \ 30 | 1 \ 25 | 0.60 \ 17 |
a5.mid | 1 \ 42 | 1 \ 35 | 1 \ 27 | 0.50 \ 7 |
a6.mid | 1 \ 37 | 1 \ 32 | 1 \ 30 | 0.70 \ 15 |
a7.mid | 1 \ 37 | 1 \ 32 | 1 \ 26 | 0.50 \ 20 |
a8.mid | 1 \ 39 | 1 \ 32 | 1 \ 19 | 0.40 \ 16 |
a9.mid | 1 \ 37 | 1 \ 34 | 1 \ 31 | 0.50 \ 17 |
a10.mid | 1 \ 43 | 1 \ 36 | 1 \ 23 | 0.40 \ 15 |
b1.mid | 1 \ 49 | 1 \ 38 | 1 \ 21 | 0.45 \ 13 |
b2.mid | 1 \ 47 | 1 \ 34 | 1 \ 24 | 0.65 \ 16 |
b3.mid | 1 \ 40 | 1 \ 31 | 1 \ 23 | 0.40 \ 16 |
b4.mid | 1 \ 41 | 1 \ 33 | 1 \ 28 | 0.40 \ 12 |
b5.mid | 1 \ 45 | 1 \ 31 | 1 \ 20 | 0.45 \ 12 |
b6.mid | 1 \ 42 | 1 \ 29 | 1 \ 22 | 0.45 \ 9 |
b7.mid | 1 \ 46 | 1 \ 31 | 1 \ 24 | 0.50 \ 15 |
b8.mid | 1 \ 47 | 1 \ 32 | 1 \ 22 | 0.45 \ 13 |
b9.mid | 1 \ 48 | 1 \ 35 | 1 \ 25 | 0.65 \ 12 |
b10.mid | 1 \ 33 | 1 \ 22 | 1 \ 20 | 0.85 \ 18 |
c1.mid | 1 \ 44 | 1 \ 34 | 1 \ 24 | 0.70 \ 15 |
c2.mid | 1 \ 42 | 1 \ 34 | 1 \ 28 | 0.43 \ 13 |
c3.mid | 1 \ 44 | 1 \ 28 | 1 \ 22 | 0.56 \ 15 |
c4.mid | 1 \ 48 | 1 \ 35 | 1 \ 24 | 0.50 \ 16 |
c5.mid | 1 \ 45 | 1 \ 38 | 1 \ 29 | 0.60 \ 18 |
c6.mid | 1 \ 43 | 1 \ 33 | 1 \ 31 | 0.53 \ 16 |
c7.mid | 1 \ 43 | 1 \ 35 | 1 \ 30 | 0.50 \ 14 |
c8.mid | 1 \ 43 | 1 \ 35 | 1 \ 28 | 0.53 \ 14 |
c9.mid | 1 \ 43 | 1 \ 31 | 1 \ 25 | 0.40 \ 14 |
c10.mid | 1 \ 41 | 1 \ 31 | 1 \ 22 | 0.53 \ 15 |
