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FER THE UNIVERSITY OF ZAGREB THE FACULTY OF ELECTRICAL ENGINEERING AND COMPUTERS |
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PROFESSIONAL REPORT No. 15
Research on the sound of a whistle for dogs
SCHWEIZER
Done: 17 February 2006
User: Petar Kunić
1A Zagorje
47242 Krnjak
The whistle for dogs, type “SCHWEIZER” HR P20050598A, was tested. The frequency of basic tone, the spectar and the level of the whistle's sound in 16 different positions were tested.
The testing was carried out in the laboratory and the rooms of the Department for electroacoustics at the Faculty of Electrical Engineering and Computers, at 3 Unska Street in Zagreb.
During testing the following equipment was used:
- Digital sound recorder Bruel&Kjaer type 2231 with a supersonic microphone Bruel&Kjaer type 4033 was used
- Calibrator Bruel&Kjaer type 4220
- Dynamic signal analyzer Hewlet-Packard type 35665A
- All equipment was gauged and suits to the requirements of sound O class measurement
Results of the measurement:
The whistle was operating by means of the biggest gush, out of the mouth of a middle-aged man. The frequency of the whistle's sound was measured and the accordions were within 40 dB below basic tone.
The level of sound was measured linearly in dB, at the distance of 1 m from the whistle, in a room without echo.
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POSITION |
FREQUENCY (kHz) |
LEVEL dB |
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1 |
3,52 |
7,28 |
10,74 |
14,32 |
99 |
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1-1 |
3,57 |
7,28 |
10,82 |
14,96 |
98 |
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1-2 |
3,70 |
14,83 |
99,5 |
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1-3 |
3,82 |
7,41 |
13,8 |
15,22 |
99,5 |
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2 |
4,21 |
8,69 |
12,93 |
15,86 |
100,2 |
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2-1 |
4,34 |
13,17 |
16,37 |
22,04 |
98 |
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2-2 |
4,59 |
9,07 |
13,68 |
16,75 |
22,09 |
101,2 |
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2-3 |
4,65 |
9,58 |
14,32 |
23,9 |
104 |
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3 |
4,85 |
9,84 |
14,7 |
18,1 |
24,4 |
101 |
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3-1 |
5,23 |
10,35 |
15,47 |
25,9 |
102 |
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3-2 |
5,49 |
10,99 |
16,37 |
21,87 |
27,5 |
100 |
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3-3 |
5,62 |
11,12 |
16,88 |
22,51 |
27,7 |
101 |
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4 |
7,00 |
12,02 |
18,04 |
24,05 |
29,55 |
103 |
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4-1 |
6,38 |
12,66 |
19,06 |
25,84 |
104 |
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4-2 |
7,41 |
14,58 |
21,86 |
29,17 |
104,6 |
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4-3 |
7,79 |
15,73 |
23,41 |
31,3 |
105,2 |
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CONCLUSION :
The sound level of the whistle is 101 dB on average, in a room without echo, at the distance of 1 m.
The range of basic frequencies , in 16 positions, is from 3,5 kHz to 7,8 kHz.
The accordions are mainly 15 to 30 dB below the tone level of basic frequency. From position 3 to position 4-3 the whistle´s sound goes into a supersonic area.
Taking into consideration the spectral system and the sound level that it makes, this whistle is not dangerous for man´s hearing.
Zagreb, 18 February 2006 Principal in charge of the Department for electroacoustics
Prof. D. Sc. Hrvoje Domitrović