Legalities
ANSI S3�19-1974 Table (NRR Table)
A1: Frequency, Hz
125
250
A2: Grand Mean Attenuation, dB
30.1
29.0
A3: Standard Deviation, dB
3.7
3.5
EN 352-2:2020 Table (SNR Table)
B1: Frequency, Hz
63
125
250
500
B2: mF (dB)
26.3
31.2
29.7
33.7
B3: sf (dB)
4.4
4.8
4.0
6.4
B4: ADVf
21.9
26.4
25.7
27.3
H = 30 dB
M = 29 dB
L = 27 dB
Bluetooth® (HFP)
Criterion input signal:
-17.7 dBFS
Sound output level at maximum input signal:
85.3 dB(A) at -14 dBFS
Usage time for maximum input signal:
3.7 h at -14 dBFS
Bluetooth® (A2DP)
Maximum sound level:
80.0 db(A) at -10 dBFS
Relationship between sound output level and input signal level
Input signal level [dBFS]
-54
-49
-44
-39
SPL [dB(A)]
70.2
75.2
80.2
82.2
500
1000
2000
3150
4000
6300
8000
37.2
36.9
35.8
36.2
36.6
42.7
45.6
4.2
4.1
3.9
4.6
5.4
5.2
4.2
1000
2000
4000
8000
SNR
35.1
33.5
32.6
44.3
31
6.7
3.5
3.7
4.0
28.4
30.0
28.9
40.3
APVf=MF-SF (dB)
-34
-29
-24
-19
-14
82.3
82.3
82.6
83.0
85.3
Important
NRR
Please read, understand, and follow all safety information�
This hearing protector is specifically designed for use in noisy
25
environments, provided it is properly used and the protector
remains clean and undamaged�
Models
IT-72 : ISOtunes FREE 2�0 EN 352
IT-73, IT-74 : ISOtunes FREE 2�0
Full manual can be found at ISOtunes.com/manuals.
The ISOtunes FREE 2�0 comes with 3 sets of TRILOGY™ Short foam
eartips (S,M,L), and 3 sets of double flange silicone eartips (S,M,L).
Choose the size that fits best in your ear canal. Remember, the
snugger the fit, the better the noise reduction. The silicone eartips
are
not tested for noise attenuation and should not be used in
noisy environments�
Fitting
1� Carefully roll the foam eartip on the stem/sound port (Fig. 1)�
2� Insert the eartip into your ear as deeply as comfortable (Fig. 2).
3� Slightly rotate earbud until it is secure in the
bowl of your ear (Fig. 3).
4� Make the earbud rest tightly next to your inner ear edge�
Improper or careless insertion of the eartip into the ear could
cause damage to the inner ear�
Introduction
Thank you for purchasing ISOtunes® FREE 2�0 Bluetooth
These earbuds have been specifically designed for use in noisy
environments – allowing you to block out much of the surrounding
earbuds�
®
EN | 12