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Wireless Information
The following table summarizes the technical details of the
wireless technology:
Wireless Hearing Aids
Antenna Type
Inductive Antenna
Antenna Dimensions
Ø1.9 mm, L – 6.5 mm
Modulation
PSK (Phase Shift Key)
Magnetic Field Strength
(at 10 m distance)
0.09 A/m (1 cm2 coil; average)
Output Power (EIRP**)
42 µW
Range
<1 m remote to hearing aid
<30 cm between aids or aid to remote
Center Frequency
3.28 MHz
Channel
Single Channel Radio
Bandwidth
67 kHz
Data-Rate
655 kbit/sec (raw channel capacity)
Data Flow
Simplex or semi-duplex capability
Protocol
Random access – no collision avoidance
S.A.R.*
5 nW/kg (BTE), 13 nW/kg (ITE)
* Specific Absorption Rating (S.A.R.) for continuous transmission
(100% duty cycle) based on 10g ICNIRP testing.
EMI/EMC COMPLIANCE
Wireless hearing aids comply with the following EMC/EMI
standards:
Standard
Test Type
Note
47 CFR Part 15,
Subpart C
RF emissions
U.S. FCC requirements for
intentional radiators.
EN 300 330-1/2 RF emissions
including
spurious emission
EMC and radio spectrum matters for
short range devices in the frequency
range 9 kHz – 25 MHz.
IEC 60601-1-2
EMC emission
immunity, RF and
ESD
Medical electrical equipment.
General requirements for basic
safety and essential performance.
Electromagnetic compatibility.
EN 301 489-1/3 Immunity, RF and
ESD
Standard for low power transmitters
in the frequency range 9 kHz – 40
GHz.
IEC 60118-13
Immunity RF near
field immunity
test
International product standard for
hearing aids to ensure adequate
immunity to radio interference from
mobile telephones.
ANSI C63.19
Immunity RF near
field immunity
test
American National Standard method
of measurement of compatibility
between wireless communication
devices and hearing aids.
ANSI/AAMI
PC69:2007
EMC immunity
Implantable medical device EMC
immunity.
EN 45502-2-1
EMC immunity
Particular requirements for
pacemakers.