Hearing Aid Compatibility

Current Project & Status

The committee is currently preparing a revision to the 2007 version of ANSI C63.19 focusing on the application of the standard to new frequency bands. In addition some specific technical issues and the correlation of the standard to user experience are being considered.

The PINS describes the purpose of current project as follows:

This project will supplement ANSI C63.19-2007 under the following scope:

Cover 698 MHz to 6 GHz and revise appropriately: articulated weighting factors, H-field requirements, correlation of test techniques, test equipment, band pass filters, power link to user experience, T-Coil positions, probe separation distance calculation, and other editorial items

The following workplan has been approved by SC8 as a more detailed plan for implementing the scope for this project.

Status / Item / Notes & Resolution
Status - Resolved
To expand the frequency range of the standard to cover 698 MHz to 6 GHz.

The extension of the lower frequency range is to include the wireless mobile technologies in 698 MHz band as mandated by recent FCC Report and Order.

The extension of the upper frequency range up is to include newer technologies in the bands between 3 - 6 GHz, including the 4.9 GHz band as referenced in the latest FCC Report and Order
700 MHz task group has conveyed its recommendations to the WG. Its changes are reflected in the current draft.
Status - TBD
a) Design/Testing and Simulation of Dipoles for the frequency extensions.
Some test has been proposed. Needs discussion and resolution in the WG.
Status - Resolved
b) Extend calibration range of test probes from 698 MHz to 6 GHz.
Issue refered to WG for IEEE 1309 and NIST Fields Measurement Group.
Status - In progress
To provide AWF factors for systems operating in the 698 MHz to 6 GHz frequency range.
WG has agreed to ratain continuity with current AWF and testing methods using slow response probes as direct measurement methods are developed.

2 proposals received for an approach to a generalized AWF factor, one to use A-Weighting and a new weighting function has been proposed by Steve Julstrom. Issue needs further discussion and resolution by the WG.

Work is needed to map a direct measurement to the categories in the current standard and bridge direct measurements to slow probe measurments. Also AWF's will be needed for slow probes.
Status - In progress
If possible to develop a generalized treatment based on A-Weighting or some other appropriate weighting to replace the AWF table.
This issue has been linked with item #2. See comments under that item.
Status - In progress
Evaluate the requirement in Clause 4, 7 and other appropriate sections for RF H-Field measurements.
Discussion has tended toward retaining the H-Field measurment but the WG has not made a final resolution on the issue.
Status - In progress
To evaluate the correlation of hearing aid immunity test results using the dipole and WB TEM methods and consider the advisability of different field strength requirements for each of the methods to bring the test methods into closer agreement.
Proposal from HIA received. WG needs to have further discussion and make a final determination.
Status - TDB
Review and update test equipment specifications generally, specifically Annex D.3, D.4 and D.7.
Item has been discussed. A volunteer is needed to take the action to review and propose wording/editing to the current text.
Status - TBD
To evaluate and possibly improve the specification of the band pass filter referenced in sub-clauses and 3.
Item has been discussed. A volunteer is needed to take the action to review and propose wording/editing to the current text.
Status - TBD
Determine and specify the power measurement that is most closely linked to user experience, peak, RMS or other parameter of power.
Item has been discussed. A volunteer is needed to take the action to review and propose wording/editing to the current text.
Status - Resolved
Reconsider the need for 3 T-Coil positions relative to user needs.
On March 4, 2008 Telecon WG agreed to use 2 positions, described as transverse and perpendicular.
Status - Resolved
The RF probe separation distance is 1.5 cm and the calibration values in table 4.2 were made at 1.0 cm. These calculations need to be redone to the 1.5 cm distance.
Values for 1.5 cm have been presented and placed in the current draft.
Status - TBD
To combine sub-clauses " Manual scanning method" and " Automated scanning method" into a single section requiring a positioning resolution and accuracy.
Status - TBD
To add a 'no RF test' option for low power transmitters that are almost certain to achieve category 4 due to their low transmission power.
Status - In progress
To review and adopt any editorial improvements proposed, including review and update of references and bibliography.
Changes are either brought to WG for consideration or reflected in draft when proposed.