© Copyright 2003 TEM Consulting, LP - All Rights Reserved Presentation To ATIS HAC IncubatorRev –...

TTEEMM CCoonnssuullttiinngg,, LLPP

© Copyright 2003 TEM Consulting, LP - All Rights ReservedPresentation To ATIS HAC Incubator Rev – 07/21/03 - HSB

Overview ofANSI C63.19

-

Wireless Hearing Aid Compatibility

Stephen BergerTEM Consultingwww.temconsulting.com

(512) [email protected]



•Background & History

•Overview of ANSI C63.19

•Possible Actions



TECHNICAL ISSUES

FOR MICROPHONE & T-COIL MODE Match Hearing Aid Immunity with Mobile

Handset Emissions

FOR T-COIL MODE only: Provide sufficient T-Coil Signal Strength and Signal Quality



HISTORY‘Hear It Now’ Petition Filed - Fall ’95FCC Summit - 1996IEC 118-13 & Australian Project Approved - 1996ANSI User Project Approved - Aug. ’96Oklahoma U. Objective & Subjective Study - Summer ’00IEC Harmonization Effort - Dec. ’99WAC Petition - Dec. ’00ANSI C63.19 Approved - Jan. ’01Revision for 3G & GTEM Approved - Feb. ’01FCC NPRM - Jan. ’02FDA Adopts ANSI C63.19 - Sept. ’02 (standard included in requirements for middle ear devices)FCC Rulemaking - July.’03ATIS HAC Incubator Formed - July ‘03



Project Scope

•Methods of Measurement and

• Parametric Criteria for:

• Hearing Aid Compatibility (HAC) with

• Wireless Communication Devices



Standard Title

American National Standard for Methods of Measurement

of Compatibility between Wireless Devices and Hearing Aids

ANSI C63.19-2001



Standard Development• Well over two dozen meetings over three

years and untold hours of investigation – Laboratory tests using hearing impaired

volunteers– Laboratory tests showing the cell phone

effects on wide range of Hearing Aids

• Used the rigorous ANSI ASC C63 balloting process including a public review by ANSI



PROJECT PARTICIPATION

HEARING AID INDUSTRYSUB-TOTAL - 21 participants from 15 organizations

WIRELESS INDUSTRY

SUB-TOTAL - 44 participants from 14 organizationsOTHER ORGANIZATIONS

SUB-TOTAL - 25 participants from 16 organizations

TOTAL 90 participants from 45 organizations



Standard Development• Work in ANSI ASC C63 Subcommittee 8

(Medical EMC)– Over 50 members on task group at time of ballot

• Food and Drug Administration• Federal Communications Commission• Testing Laboratories• Hearing Aid/Cell Phone Manufacturers• Hearing Industries Association• Universities• Hearing Aid Research Organizations• Consultants



Overview of StandardSummary of Sections

– Sections 1-3 – Introductory Material

• Overview

–

Scope

–

Purpose

–

Organization of document

• References

• Definitions, acronyms, and abbreviations




– Section 4 – Test of Phone RF Emissions

• Test equipment and facilities

• Test set-up and validation

• Near-field test procedure




– Section 5 – Test of HA RF Immunity

• Test facilities and equipment

• Test set-up and validation

• RF immunity test procedure (Key element)



Hearing Aid ImmunityTest Setup

Frequency Analyzer

Pre-Amp

Ear Coupler

Microphone

Power Meter (Pin)

Power Meter (Pout)

Amplifier RF Generator Cell Phone Mod. Sim.

Directional Coupler

Audio Signal Generator

Electro-acoustic Transducer

Dipole Antenna




– Section 6 – Test of Phone T-Coil Signal

• Test facilities and equipment

• Test configurations and set-up

• Test procedure for audio band magnetic field



Phone T-Coil SignalTest Setup

Antenna replacedwith Coaxial Connection

ProbeCoil

ReferenceBase Station

Simulator

InterfaceConnection

GraphicsRecorder

PowerSupply

SignalSource

Integrator

Anechoic chamber for RF and acoustic sheilding (optional)

1/3 Octave Bandpass

Filter

Controller

RMS VoltmeterHandset

Optional Power Supply allowed for baseband signal measurement only.It is not allowed for noise measurements.

NOTE:

(Shown in Axial Postion)




– Section 7 – HA Performance Criteria

• Articulation weighting factor

• Audio coupling mode

• Audio band magnetic coupling mode

• Accessories and options



MANY POSSIBLE RF SOLUTIONS

HEARING AID IMMUNITY

HA

ND

SET

EM

ISSI

ON

S

USABLE GOOD EXCELLENT



Eliminated by FCC

Rulemaking



Section 7 –RF Performance Criteria

RF PARAMETERS

Category

Hearing Aid Parameters (Hearing Aid must maintain

< 55 dB IRIL interference level and < 6 dB Gain Compression) Telephone Parameters

NEAR FIELD E-Field Immunity (CW dB(V/m))

H-Field Immunity (CW dB(A/m))

E-Field Emissions (CW dB(V/m))

H-Field Emissions (CW dB(A/m))

Category U1 30.0 - 35.0 dB (V/m) -23.0 - -18.0 dB (A/m) 46 - 51 dB(V/m) + 0.5 x AWF -4.4 - 0.6 dB(A/m) + 0.5 x AWF

Category U2 35.0 - 40.0 dB (V/m) -18.0 - -13.0 dB (A/m) 41- 46 dB(V/m) + 0.5 x AWF -9.4 - -4.4 dB(A/m) + 0.5 x AWF

Category U3 40.0 - 45.0 dB(V/m) -13.0 - -8.0 dB (A/m) 36 - 41 dB(V/m) + 0.5 x AWF-14.4 - -9.4 dB(A/m) + 0.5 x AWF

Category U4 >45.0 dB (V/m) >-8.0 dB (A/m) <36 dB(V/m) + 0.5 x AWF <-14.4 dB(A/m) + 0.5 x AWF

Category UX special special special special



Section 7 –RF Performance Criteria

SYSTEM CLASSIFICATION

System ClassificationArticulation

Index U Category SumAI Sum of Hearing Aid (U Category) + Telephone (U

Category)

Usable 0.3 Hearing Aid (U Category) + Telephone (U Category) = 4Normal Use 0.5 Hearing Aid (U Category) + Telephone (U Category) = 5Excellent Performance 0.7 Hearing Aid (U Category) + Telephone (U Category) >= 6



Section 7 –T-Coil Requirements

• T-Coil Signal Strength

• T-Coil Signal Frequency Response

• T-Coil Signal Quality



Section 7.3.1 –T-Coil Signal Strength

5

1

2

3

4

3

1

MeasurementPlane

ReceiverAxis

Axial

MeasurementLocation

MeasurementRadial

Locations

(1,2,3,&4)

MeasurementRadius

10 mm

16 mm

R.M.

.

.

.

AXIALLocation

5

Secondary Auxiliary

Axis(Example)

Axial -13 dB (A/m) (.22 A/m)

Radial -18 dB (A/m)

(.13 A/m)



Section 7.3.2 –T-Coil Frequency Response

MAGNETIC FIELD STRENGTH RELATIVE TO 1000 Hz

-20

-10

0

10

20

300 500 1000 2000 3300FREQUENCY (Hz)

dB

Rel

ativ

e to

Val

ue

at 1

kH

z

-6 dB/Oct.

-4 dB/Oct.

6 dB/Oct.

+2 dB

-2 dB



Section 7.3.3 –T-Coil Signal Quality

MAGNETIC COUPLING PARAMETERSCategory Hearing Aid Parameters Telephone Parameters

Near Field Immunity (w / 27.8 dBm CW into Dipole)

WD Signal Quality (Signal+Noise-to-Noise Ratio in dB)

Category U1T 75 - 85 dB(IRIL) -10 - -20 dB + AWFCategory U2T 65 - 75 dB(IRIL) 0 - -10 dB + AWFCategory U3T 55 - 65 dB(IRIL) 10 - 0 dB + AWFCategory U4T <55 dB(IRIL) >10 dB + AWFCategory UXT special special

(NOTE: A comparable hearing aid immunty test can be performed byfixing the acoustic output power requirement at 75 dB(IRIL) for all categories and varying the power into the dipole from 22.8 dBm for category U0, increasing by +5 dB for each higher category.)




– Section 8: Calibration and measurement uncertainty

• General

• Ambient conditions

• Specific calibration requirements

• Measurement uncertainty




– Section 9 Test Report

• Test plan

• Applicable standards

• Equipment unit tested

• Test configuration

• List of test equipment

• Units of measurement



Overview of StandardSummary of Annexes

– Definition of reference axes

– Acoustic test frequencies

– Equipment and set-up calibration

– Test equipment specifications

– Sample measurement uncertainty estimates

– Use of Helmholtz coils for calibration

– RF envelope comparison for US Wireless Communications devices

– Explanation of rationale used in standard

– Alternate test method for RF immunity



Effectiveness of StandardOklahoma University Validation Studies

– Objective Study – 10 Phones / 8 HA

• Predicted Result– 38.8 % Excellent– 28.8% Recommended– 67.6% Recommended or Better

• Actual Result– 41.7 % Excellent– 26.4% Recommended– 68.1% Recommended or Better

– Test Accuracy

– 51.4% Exact Match– 93.1% Exact Match or Better Than Predicted

Performance



Effectiveness of StandardOklahoma University Validation Studies

– Subjective Study – 18 Subjects / 6 Phones

– Test Accuracy

• 6 Hearing Aids were good with all phones

• Some Hearing Aids were not acceptable with any phone

• There is a middle ground where a Hearing Aid / Phone combination must be tried by the user.

– Some users will find the combination perfectly acceptable

– Other users, with the same test results will find the combination unacceptable



GTEM – Dipole IlluminationTest Repeatability

(Max. Reading) – (Min. Reading) (dB)

900 MHz

GTEM Dipole Center Dipole TipT-Coil Mode 5.8 6.5 6.6Mic Mode 2.7 5.2 8.6

1900 MHz

GTEM Dipole Center Dipole TipT-Coil Mode 11.9 6.8 5.1Mic Mode 5.0



Considerations for Next Revision

Elimination of analog requirement.

Reduction in number of test positions for HA.Phone RF - Eliminate H-Field test

HA RF – Harmonize with IEC 60118-13

T-Coil – Change test positions

T-Coil – Develop isotropic probe

T-Coil – Implement FFT method for Freq. Resp.

T-Coil – Move to straight A-Weighted S/N

Move from parametric to end result based test



Summary A significant effort has been underway since 1995 to assure that hearing aid users could use digital wireless devices.

Both industries (cell phone and hearing aid) have made significant advances and have many products which work quite well together.

The ANSI C63.19 Standard provides compatibility.

Consensus recommendations with supporting technical data needed for the next edition of C63.19

© Copyright 2003 TEM Consulting, LP - All Rights Reserved Presentation To ATIS HAC IncubatorRev –...

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