Jacopo Fogola, Stefano Masera, Vincenzo Bevacqua
Environmental Protection Agency - Piedmont Region, Turin, Italy
AS
OBJECTIVES
1. To study accuracy and precision of environmental noise
measurements through smartphones
SMARTPHONES AND APPS
SMARTPHONES
1.Samsung @chat GT-B5330
(Android v.4.0.4)
2.Samsung Advance GT-I9070P
(Android v.2.3.6)
3.HTC Desire 601 (Android
v.4.4.2)
4.iPhone 4S (iOS v.8.0.2)
5.iPhone 5S (iOS v.8.1.3)
APPS
Noise Meter
NOISE METER FOR ANDROID
•
Sampling frequency adjustable: 8000, 11025, 22050, 44100, 48000 Hz
•
1 dB steps gain, in the range -40 - +40 dB
•
Integration period from 1 sec to 10 minutes
•
Events detection
•
Digital filters: low-high-band pass, A ponderation
•
Data capture: peak, minimum, maximum, arithmetic average, energetic
average (equivalent level)
•
Data storage in a txt file
•
NO frequency spectrum
NOISE IMMISSION ANALYZER FOR IOS
•
Sampling frequency: 44100 Hz
•
Calibration with a known signal
•
Digital filters: A-B-C-linear ponderation, fast, slow
•
Data capture: minimum, maximum, energetic average (equivalent level)
•
Audio file record up to 20 seconds
LABORATORY MEASUREMENTS
Comparison of the response to white noise at different SPL
with a class 1 sound level meter
LABORATORY MEASUREMENTS
Internal microphone
25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 Professional sound level meter - dB(A)S m ar tp ho ne s - dB (A ) iPhone 5s iPhone 4s HTC 601
Sam s ung Advance Sam s ung @chat
LABORATORY MEASUREMENTS
Headphones with microphones
25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 Professional sound level meter - dB(A)
S m ar tp ho ne s - dB (A ) iPhone 5s iPhone 4s HTC 601
Sam s ung Advance Sam s ung @chat
LABORATORY MEASUREMENTS
Class 2 external microphone (MicW i436)
25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 Professional sound level meter - dB(A)
S m ar tp ho ne s - dB (A ) iPhone 5s iPhone 4s HTC 601
OUTDOOR MEASUREMENTS
Comparison between Samsung Advance (headphone with microphone) and
class 1 sound level meter - Traffic noise measurement for
100 days
OUTDOOR MEASUREMENTS
OUTDOOR MEASUREMENTS
OUTDOOR MEASUREMENTS
5 minutes statistics
LAeq,Class 1 – LAeq smartphone dB(A)
Day Nig Den
Minimum -3,3 -1,9 -1,6
Average -0,5 0,3 -0,1
Maximum 1,6 2,5 1,3
FROM SMARTPHONES
TO A
+
•
Sound card automatically
recognized by the PC as an audio
device
•
Powered and connected to PC
through USB
•
Digital MEMS microphones
•
62.6 dB signal-to-noise ratio
•
120 dBSPL acoustic overload point
•
–26 dBFS sensitivity
STEVAL-MKI116V1
•
Android 4.4.2
•
ARM Cortex-A9 quad core @
1.6Ghz
•
2GB DDR3 @ 800Mhz
•
Wifi
•
Bluetooth
•
USB
•
HDMI
RADXA ROCK
PRO
Comparison with a Class 1 sound level
meter (outdoor measurements for 19
days )
(6-22)Day (6-20)Day Evening(20-22) Night (22-6) DEN
Min -0,8 -0,7 -1,5 -1,6 -1,4
Average -0,1 -0,1 -0,1 -0,1 -0,1
Max 0,5 0,5 0,4 0,8 0,4
Standard
40 45 50 55 60 65 70 75 80 85 40 45 50 55 60 65 70 75 80 85
Class 1 Noise Meter - dB(A)
M in i-p c R ad xa d B (A ) Min -9,8 Average 0,2 Max 9,5 Standard deviation 1,0 Count 5474
5 min statistic
45 50 55 60 65 70 75 80 85 16 /0 6/ 15 17 /0 6/ 15 18 /0 6/ 15 19 /0 6/ 15 20 /0 6/ 15 21 /0 6/ 15 22 /0 6/ 15 23 /0 6/ 15 24 /0 6/ 15 25 /0 6/ 15 26 /0 6/ 15 27 /0 6/ 15 28 /0 6/ 15 29 /0 6/ 15 30 /0 6/ 15 01 /0 7/ 15 02 /0 7/ 15 03 /0 7/ 15 04 /0 7/ 15 05 /0 7/ 15 06 /0 7/ 15 07 /0 7/ 15 08 /0 7/ 15 dB (A ) Mini pc Radxa Class 1 Noise Meter