ETSI TR 102 791 V1.1.1 (2012-05)

Technical Report
Electromagnetic compatibility
and Radio spectrum Matters (ERM);
System Reference Document;
Short Range Devices (SRD);
Technical characteristics of wireless aids for
hearing impaired people operating in the VHF and
UHF frequency range
2 ETSI TR 102 791 V1.1.1 (2012-05)

Reference
DTR/ERM-TG17WG3-009
Keywords
audio, hearing aid, SRD
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
Individual copies of the present document can be downloaded from:
http://www.etsi.org
The present document may be made available in more than one electronic version or in print. In any case of existing or
perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF).
In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive
within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, please send your comment to one of the following services:
http://portal.etsi.org/chaircor/ETSI_support.asp
Copyright Notification
No part may be reproduced except as authorized by written permission.
The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2012.
All rights reserved.
TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.
TM
3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI
3 ETSI TR 102 791 V1.1.1 (2012-05)
Contents
Intellectual Property Rights . 5
Foreword . 5
Executive summary . 5
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions, symbols and abbreviations . 8
3.1 Definitions . 8
3.2 Symbols . 9
3.3 Abbreviations . 9
4 Comments and status of the System Reference Document . 9
4.1 Comments on the System Reference Document . 9
5 Background to Current Systems . 9
6 Market information. 10
7 Technical information . 12
7.1 Detailed technical description . 12
7.1.1 Requirements . 12
7.2 Technical parameters and implications on spectrum . 13
7.2.1 Current ITU and European Common Allocations . 13
7.2.2 Sharing and compatibility studies (if any) already available . 13
7.2.3 Sharing and compatibility issues still to be considered. 13
7.2.4 Transmitter parameters for Telecoil Replacement Service operating at VHF and UHF frequencies . 13
7.2.5 Unwanted emissions . 13
7.3 Information on relevant standard(s) . 13
8 Radio spectrum requirement and justification . 14
8.1 Justification . 14
8.2 Requirement . 15
9 Regulations . 15
9.1 Current regulations . 15
9.1.1 Current regulations in Europe for aids for hearing impaired . 15
9.2 Proposed regulation and justification . 17
9.2.1 Proposed Regulation . 17
9.2.2 Justification . 17
Annex A: Detailed presentation of the system . 18
A.1 Hearing loss . 18
A.2 Types of hearing aids . 19
A.2.1 Air conductive hearing aids . 19
A.2.2 Implanted hearing aids . 19
A.2.3 Advanced Digital Signal Processing Hearing Aids . 20
A.2.4 Digital wireless accessories for additional applications . 21
A.2.5 Assistive Listening Devices . 22
A.2.5.1 Induction Loop (IL) Systems . 22
A.2.5.2 Infrared (IR) Systems. 23
A.2.5.3 Frequency Modulated (FM) Radio Systems . 23
ETSI
4 ETSI TR 102 791 V1.1.1 (2012-05)
Annex B: Expected market size and value . 28
B.1 Air conductive hearing aids . 29
B.1.1 Behind-the-ear . 29
B.1.2 In the ear, in the canal and completely in the canal . 29
B.2 Assistive listening systems (often described as FM systems) . 29
B.3 Traffic and equipment density forecast . 30
Annex C: Bibliography . 31
History . 32

ETSI
5 ETSI TR 102 791 V1.1.1 (2012-05)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Electromagnetic compatibility and Radio
spectrum Matters (ERM).
Executive summary
Developments in hearing health care have seen the dawn of the need to interconnect hearing aid devices wirelessly. This
is referred to as a body network configuration, namely from the left ear to the right ear and vice versa, but also from
hearing aids to nearby peripherals (such as mobile phones), control devices (such as remote controls for the hearing
aid), relay stations and remote microphones. Some existing techniques for connecting to nearby peripherals such as
inductive "Telecoil" systems do not meet today's information rich world and the present document seeks to provide this
social service in an enhanced format.
The proponents of the present document believe that use of these radio systems may require minor amendments to the
present regulatory framework for some target bands.
CEPT/ERC Recommendation 70-03 [i.1], annex 10 identifies frequencies for Radio microphones and Assistive
Listening Systems including aids for hearing impaired. In parallel, ETSI has also published the Harmonized European
Standard EN 300 422-2 [i.3].
The present document aims to describe the existing and near future technology employed in aids for hearing impaired
people and requests access to additional spectrum in the VHF or UHF frequency range for operation of this equipment.
The purpose of producing the present document is to inform CEPT of the current state-of-the-art of the aids for hearing
impaired and provide the ability of industry to quickly bring innovative and useful products that cater to hearing health
to the market while avoiding any harmful interference with other services and equipment operating in the same band. A
continuing license exempt regulation status for these types of applications is requested.
Introduction
The present document has been developed to support the co-operation between ETSI and the Electronic
Communications Committee (ECC) of the European Conference of Post and Telecommunications Administrations
(CEPT).
Status of the System Reference Document
The present document has been developed by ETSI TC ERM TG17 WP 3. It has undergone coordination by ERM and
two resolution meetings, following these the references to the 400 MHz band has been removed. The current version
requests spectrum for a Telecoil Replacement Service (TRS).
EHIMA supports the objectives of the present document.
ETSI
6 ETSI TR 102 791 V1.1.1 (2012-05)
1 Scope
The present document describes the current state of the art of ALDs for hearing impaired people using the VHF and
UHF frequency range and requests spectrum for a Telecoil replacement Service.
It includes in particular:
• market information;
• technical information;
• regulatory issues.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] CEPT/ERC Recommendation 70-03: "Relating to the use of Short Range Devices (SRD)".
[i.2] CEPT/ERC Report 14: "Develop a strategy to improve the effectiveness and flexibility of
spectrum availability for Short Range Devices (SRDs)".
[i.3] ETSI EN 300 422-2: "Electromagnetic compatibility and Radio spectrum Matters (ERM);
Wireless microphones in the 25 MHz to 3 GHz frequency range; Part 2: Harmonized EN covering
the essential requirements of article 3.2 of the R&TTE Directive".
[i.4] Council Directive 93/42/EEC of 14 June 1993 concerning medical devices.
[i.5] Commission Decision 2005/928/EC of 20 December 2005 on the harmonisation of the
169,4-169,8125 MHz frequency band in the Community (OJ L 344, 27.12.2005, p. 47-51).
[i.6] ECC/DEC/(05)02: "ECC Decision of 18 March 2005 on the use of the Frequency Band
169.4-169.8125 MHz".
[i.7] Launer, S. 2003 Wireless Solutions - The State of the Art and Future of FM Technology for the
Hearing Impaired Consumer, In Proceedings from the 1st International FM Conference:
"Achieving Clear Communication Employing Sound Solutions - 2003": 31-38.
ETSI
7 ETSI TR 102 791 V1.1.1 (2012-05)
[i.8] Ricketts, T. A., and Dittberner, A. 2002. Directional Amplification for Improved Signal to Noise
Ratio: Strategies, Measurements and Limitations. Hearing Aids: Standards, Options and
Limitations. M. Valente. Stuttgart, Thieme. Second edition.
[i.9] Crandell, C. 1991. Individual differences in speech recognitions ability: Implications for hearing
aid selection. Ear and Hear 5: 100-107.
[i.10] Helfer, K., and Huntley, R. 1991. Aging and consonant errors in reverberation and noise. Journal
of the Acoustical Society of America 90(4): 1786-1796.
[i.11] Needleman, A., and Crandell, C. 1995. Speech recognition in noise by hearing-impaired and noise-
masked normal-hearing listeners. Journal of the American Academy of Audiology 6: 414-424.
[i.12] Killion, M. 1997. SNR loss: "I can hear what people say but I can"t understand them." The
Hearing Review 4(12): 8-14.
[i.13] Moore, B. 1997. An introduction to the psychology of hearing (4th Edition). San Diego: Academic
Press.
[i.14] Dubno, J., Dirks, D., and Morgan, D. 1984. Effects of age and mild hearing loss on speech
recognition in noise. Journal of the Acoustical Society of America 76(1): 87-96.
[i.15] Hawkins, D., and Yacullo, W. 1984. Signal-to-noise advantage of binaural hearing aids and
directional microphones under different levels of reverberation. Journal of Speech and Hearing
Disorders 49: 278-285.
[i.16] Duquesnoy, A., and Plomp, R. 1983. The effect of a hearing aid on the speech-reception threshold
of hearing impaired listeners in quiet and in noise. Journal of the Acoustical Society of America
73(6): 2166-2173.
[i.17] Plomp, R. 1986. A signal-to-noise ratio model for the speech-reception threshold for the hearing
impaired. Journal of Speech and Hearing Research 29: 146-154.
[i.18] Kochkin, S. 1994. MarkTrak III: Why 20 million in US don't use hearing aids for their hearing
loss. The Hearing Journal 46(1): 20-27, 46(2): 26-31, 46(4): 36-37.
[i.19] Valente, M., Crandell, C. C., Lewis, M.S., and Enrietto J. 2003 Improving Speech Recognition in
Noise: Directional Microphone and FM Systems, In Proceedings from the 1st International FM
Conference: "Achieving Clear Communication Employing Sound Solutions - 2003": 39-52.
[i.20] Ross, M. 1994 FM Large-Area listening Systems. In Communication Access for Persons with
Hearing Loss, Ross, M. (Ed), 51-70. Timonium, MD: York Press, Inc.
[i.21] Crandell, C., and Smaldino, J. 2000. Room acoustics for listeners with normal hearing and hearing
impaired. In M.Valente., H. Hosford-Dunn and R. Roeser. (eds.), Audiology: treatment strategies
(pp. 601-638), New York: Thieme Medical Publishers.
[i.22] Crandell, C., and Smaldino, J. 2001. Improving classroom acoustics: Utilizing hearing-assistive
technology and communication strategies in the educational setting. Volta Review 101(5): 47-62.
[i.23] Bakke, M. H., Levitt, H., Ross, M., & Erickson, F. 1999. Large area assistive listening systems
(ALS): Review and recommendations: Final report to United States Architectural and
Transportation Barriers Compliance Board (U.S. Access Board), Lexington School for the
Deaf/Center for the Deaf, Rehabilitation Engineering Research Center on Hearing Enhancement,
New York. Retrieved January 24, 2006.
[i.24] Ledermann, N., and Hendricks, P. 2003. "Induction Loop Assistive Listening Systems: A
Venerable Technology meets the New Millenium" Seminars in Hearing 24(1): 81-92.
[i.25] Yanz, J. L., and Preves, D. 2003. "Telecoils: Principles, Pitfalls, Fixes, and the Future." Seminars
in Hearing 24(1): 43-62.
[i.26] Ross, M. 2003 FM Systems: A Little History and Some Personal Reflections. In Proceedings from
the 1st International FM Conference: "Achieving Clear Communication Employing Sound
Solutions - 2003": 17-28.
ETSI
8 ETSI TR 102 791 V1.1.1 (2012-05)
[i.27] Helfer, K., and Wilber, L. 1990. Hearing loss, aging, and speech recognition in reverberation and
noise. Journal of Speech and Hearing Research 33: 149-155.
[i.28] Nikoloski N., 2008 FM Technology - Regulatory Challenges and Global Harmonization Efforts, In
Proceedings from the 2nd International FM Conference: "Achieving Clear Communication
Employing Sound Solutions - 2008", in press.
[i.29] Shield, B., 2006 Evaluation of the social and economic costs of hearing impairment. Report for
Hear-it.
NOTE: Available at www.hear-it.org.
[i.30] Kochkin, S. 2005 MarkeTrak VII Survey, Hearing Review.
NOTE: Available at www.hear-it.org.
[i.31] ECC Report 55: "Compatibility between existing and proposed SRDs and other
Radiocommunication applications in the 169.4-169.8 MHz frequency band".
[i.32] Boymans, M.; Theo Goverts, S; Kramer, Sophia E.; Festen, Joost M.; Dreschler, Wouter A., "A
Prospective Multi-Centre Study of the Benefits of Bilateral Hearing Aids", Ear and Hearing., vol.
29(6), pp. 930-941, Dec. 2008.
NOTE: Available at http://www.hear-it.org.
[i.33] Recommendation T/R 20-08: "Frequency planning and frequency for the GSM system".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
aids for hearing impaired: all types of hearing aids and their accessories as well as all types of assistive listening
systems for hearing impaired people
Assistive Listening System (ALS): systems utilizing electromagnetic, radio or light waves, or a combination of these,
to transmit the acoustic signal from the sound source (a loudspeaker or a person talking) directly to the hearing impaired
person
emission bandwidth: width of the signal spectrum between the points on either side of carrier centre frequency that is
20 dB down relative to the maximum level of the modulated carrier
NOTE: Compliance is determined using instrumentation employing a peak detector function and a resolution
bandwidth approximately equal to 1 % of the emission bandwidth of the device under test.
hearing aids: medical devices in the context of Directive 93/42/EEC (MDD) [i.4] comprising electro acoustic
amplifiers including a microphone and a loudspeaker and having a frequency response and dynamic characteristics
specific to each person's individual hearing loss
personal hearing aid system: radio communication system comprising one narrow band transmitter, which can be
handheld, on a table or around the neck of a hearing impaired person and one or more receivers, where each receiver
can have wired or inductive connection to a hearing aid
public hearing aid system: broadcast radio communication system comprising one transmitter (up to 500 mW), which
is installed at a fixed location in a large auditorium, e.g. in a church or theatre and one or more receivers, where each
receiver can have wired or inductive connection to a hearing aid
ETSI
9 ETSI TR 102 791 V1.1.1 (2012-05)
Telecoil: Audio Induction Loop systems, also called audio-frequency induction loops (AFILs) or hearing loops are an
aid for the hard of hearing
NOTE: They are a loop of cable around a designated area, usually a room or a building, which generates a
magnetic field picked up by a hearing aid. The benefit is that it allows the sound source of interest -
whether a musical performance or a ticket taker's side of the conversation - to be transmitted to the
hearing-impaired listener clearly and free of other distracting noise in the environment. Typical
installation sites would include concert halls, ticket kiosks, high-traffic public buildings (for PA
announcements), auditoriums, places of worship, and homes. In the United Kingdom, as an aid for
disability, their provision where reasonably possible is required by the Disability Discrimination Act
1995, and they are available in "the back seats of all London taxis, which have a little microphone
embedded in the dashboard in front of the driver; at 18,000 post offices in the U.K.; at most churches and
cathedrals".
3.2 Symbols
For the purposes of the present document, the following symbols apply:
f Frequency
P Power
R Distance
t Time
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ALD Assistive Listening Devices
dB decibel
dBi decibel relative to an isotropic radiator
ECA European Common Allocation
EMC Electro Magnetic Compatibility
e.r.p. effective radiated power
eirp effective isotropic radiated power
HIBAN Hearing Instruments Body Area Networks
IL Induction Loop
IR Infrared
R&TTE Radio and Telecommunications Terminal Equipment
SNHL SensoriNeural Hearing Loss
SRD Short Range Device
TRS Telecoil Replacement Service
4 Comments and status of the System Reference
Document
4.1 Comments on the System Reference Document
5 Background to Current Systems
Historically, hearing aids consisted of little more than basic "miniature audio amplifiers" placed in or behind their ear(s)
solely boosting the incoming sounds. As semiconductor technology has evolved and become miniaturised, hearing
impaired people enjoy extremely sophisticated digital systems incorporating a range of communication capabilities.
ETSI
10 ETSI TR 102 791 V1.1.1 (2012-05)
State-of-the-art technology uses specialized Digital Signal Processing (DSP) technology that is advanced enough to
fulfil the stringent mechanical (ultra miniature) and power consumption (only one small single cell battery)
requirements that are specified for modern hearing aid devices. DSPs manipulate the incoming sound spectrum
mathematically, converting it into a digital representation; programmable software then manipulates this digital
representation to achieve:
• background noise reduction;
• correction of patient specific deficiencies;
• enhancement of sound cues and other listening parameters used by the brain to reconstruct normal hearing.
Hearing aids contribute to patient safety, comfort and enjoyable listening experience. However, real life offers an
incredible richness in different listening environments in some of which even the most sophisticated hearing
instruments show only a limited benefit. Examples of acoustic environments or listening situations where the
performance of conventional hearing instruments can substantially be improved by applying additional communication
devices are the following:
• reverberant environments such as big churches or lecture halls;
• communication over larger distances, e.g. in a lecture or in a classroom;
• communication on the telephone, especially cell phones.
In these environments the application of assistive listening systems (ALS) based on wireless communication
technologies offer substantial additional benefits and significantly improve speech intelligibility [i.7]. The advent of
digital broadcasting is now displacing some of the frequencies where these wireless ALS's have traditionally operated.
In North America and Europe, approximately 1 person in 10 has some form of hearing loss, from mild to severe. Today
only 20 % of these people are assisted by hearing aid technology. The binaural rate (wearing two hearing aids: one left
and one right) is ~75 % to 80 % in North America, ~60 % in Europe and 10 % to 12 % in the rest of the world. Reasons
for such low adoption rates in general vary from negative stigma associated with wearing cosmetically non-appealing
devices to high cost and certain types of hearing losses that could not be corrected.
Recent progress made in binaural hearing health revealed that having for example the right hearing aid being able to
communicate with the left hearing aid and vice versa helps achieve another level of breakthrough in restoring someone's
hearing. This also directly contributes to the safety of that person's listening environment, for example directionality of
sounds can be better perceived, in cases such as an approaching ambulance or fire truck which cannot be seen but only
heard, is physically located. In some instances where one ear is totally impaired, sounds captured from that side of the
head can be relayed to the other ear and processed such as that person experiences full 360° hearing again.
A major role of allowing the hearing impaired to communicate and also enjoy similar experiences to those with normal
hearing has been played by the Telecoil system (clause A 2.5.1) which is in worldwide use. Unfortunately these are
difficult or impossible to install in large public places such as airports and train stations and are both expensive to install
and maintain. Also building owners are often reluctant to allow them to be installed. In addition they only supply a
single low quality voice channel. To implement a Telecoil replacement service effectively wireless technology and its
associated spectrum are required, which will greatly benefit the hearing impaired.
For further detailed information, see annex A.
6 Market information
Hearing loss in general
In Europe, about 71 million adults aged 18 years to 80 years have a hearing loss greater than 25 dB, which is the
definition of hearing impairment recognized by the World Health Organization (WHO). In the EU alone, the number of
people with hearing loss is more than 55 million. The data on hearing loss in Europe is reported in the scientific survey,
"Evaluation of the Social and Economic Costs of Hearing Impairment" [i.29]. According to the report, just one in six of
those who could benefit from using hearing aids are being treated with hearing aids.
ETSI
11 ETSI TR 102 791 V1.1.1 (2012-05)
Numerous scientific surveys show that the satisfaction among hearing aid users is high, and several studies have
concluded that the use of hearing aids causes significant improvement in the quality of life. Furthermore, two recent
studies (one conducted by researchers at the Academic Medical Centre of the University of Amsterdam and a second
one conducted by Karolinska Instituttet in Stockholm) have reported that hearing aid users prefer using two hearing aids
than using a single device. The Dutch study has found that having tried both for limited time periods, 93 % preferred
using two hearing aids rather than one because of improved speech recognition and sound discrimination. The findings
were supported by the Swedish study, indicating an 18 percent improvement in speech recognition with two hearing
aids, as compared to 13 % improvement with a single hearing aid [i.32].
Hearing loss in different countries
The report findings make it possible to calculate the numbers of people with hearing impairment in any given region or
area in Europe and other industrialized nations.
Some examples:
• Germany: 10,2 million.
• France: 7,6 million.
• United Kingdom: 7,5 million.
• Italy: 7,2 million.
• Spain: 5,5 million.
• Poland: 4,7 million.
• The Netherlands: 2 million.
The data and calculations presented in [i.29] show that the cost to Europe of hearing impairment of all grades is
284 billion Euros for the year 2004, and 224 billion Euros for the European Union. These costs has been arrived at by
taking a 'quality of life' approach, which will account for overall effects, including the psychosocial impacts of hearing
loss.
Hearing loss is the third most widespread chronic affliction in the United States, surpassed only by arthritis and
hypertension. The frequency is assumed to be similar in Canada. According to [i.30]:
• More than 31 million Americans were hearing impaired, corresponding to more than 10,5 % of the population
in the United States.
• More than 24 million of them did not have a hearing aid.
• Only about 23,5 % of hearing impaired Americans actually use hearing aids.
Since 2000, when the last survey was conducted, the number of hearing impaired people in the US has increased from
28,6 million to almost 31,5 million. According to the same study, projections on the North American population with
hearing loss through 2050 indicate that the hearing loss population will increase to almost 53 million and that the
number will surpass 40 million by 2025.
Among children, hearing loss is common in both the US and Canada, according to several studies. In Canada, six babies
in 1,000 are born with some degree of hearing loss making the total number of hearing impaired newborn Canadians
approximately 1,000 per year. Approximately one American school aged child in ten suffers from some form of hearing
loss.
In 1995 the UN World Health Organization, WHO, estimated that more than 25 million people in Southeast Asia suffer
from "disabling" hearing loss. In Thailand, data indicates that approximately 13,5 % of the population suffers from
hearing loss.
• In China, six in every 1,000 infants screened are hearing impaired.
• In rural Pakistan, one child in 12 is suffering from hearing loss.
• In Thailand, on average 13,6 % suffer from different degrees of hearing loss.
ETSI
12 ETSI TR 102 791 V1.1.1 (2012-05)
In many less developed areas of countries such as Malaysia, India, Pakistan and Saudi Arabia, the knowledge and
awareness of hearing loss is low [i.30].
Further detailed market information can be found in annex B.
7 Technical information
7.1 Detailed technical description
Devices operating at VHF and UHF frequencies at present.
At present, a typical system of ALSs comprises.
• A multi-frequency FM transmitter (body worn or handheld) with direct channel synchronization, entirely new
multi-talker network possibility for team teaching environments or a Bluetooth connection to a mobile phone.
• A miniaturized multi-frequency receiver with flexible channel management. The receiver can be directly
connected to the hearing aid or worn around the neck.
• In the school environment a third component can be added to an FM System - an automatic channel
synchronizer mounted on the wall of a room for all students entering that room.
• In cases of big events attended by many hearing impaired people, i.e. typically for large auditoriums, theatres,
churches or other public places, public hearing aids systems can be employed. The transmitter and receiver
parameters for public hearing aids systems are defined in ECC Report 55 [i.31], ECC Decision
ECC/DEC/(05)02 [i.6] and EC Decision 2005/928/EC [i.5]).
During the last several years, digitally operating hearing aid devices as well as digital ALSs operating at UHF
frequencies have been placed on the European market. Due to the lack of worldwide harmonized spectrum for these
devices, hearing instruments' manufacturers have been forced to find appropriate solutions in the available 900 MHz
and 2,4 GHz ISM bands.
NOTE: In Europe the 900 MHz ISM band is not available. Instead the band 863 MHz to 865 MHz is used for
wireless audio applications.
The hearing aid devices, which are operating in these bands are body worn medical devices (in and around the ear) in
the context of Directive 93/42/EEC (MDD) [i.4]. They can be described as body worn therapeutic medical devices used
to provide improved medical treatment of a patient. The ALSs and the accessories for hearing aids can be also classified
as medical devices or non-medical devices depending on their connection to the hearing instruments and their intended
use in the sense of Directive 93/42/EEC (MDD) [i.4].
7.1.1 Requirements
Hearing aids can be described as body worn therapeutic medical devices used to provide improved medical treatment of
a patient. Therefore, they are subject to the very same constraints as all other body worn medical devices:
• They perform therapeutic tasks aimed a treating, curing, hence bettering patient's lives.
• They are installed / worn in and around the body.
• They are subject to sever power consumption constraints, due to their discreet mechanical size, that commands
very small source of energy (single cell battery).
• They need a worldwide deployable band to accommodate for travelling patients.
• They need the radio spectrum to be optimized in terms of energy spent for range and link robustness achieved,
hence a low noise floor and minimal interference band, where body tissue absorption and spectrum usage
density are taken into account.
• They should not be subject to undue interference as this is both frightening and in some cases dangerous to the
user.
ETSI
13 ETSI TR 102 791 V1.1.1 (2012-05)
After detailed consideration of spectrum up to 2 GHz and taking in the points outlined above (especially the world wide
requirement) the existing ISM and SRD band have been excluded, the only spectrum which is worldwide and likely to
be reasonably interference free are: 156,4875 to 156,5625 and 156,7625 to 156,8375 (T/R 20-08 [i.33], annex 1)
Maritime , these could be used in conjunction with the existing 169 MHz band in Europe and Japan and the 216 MHz
band in USA or 960 MHz to 1 164 MHz Band Aeronautical.
During the ETSI consultation stage information on the new proposed SRD bands 870 MHz to 876 MHz and 915 MHz
to 921 MHz has become available and it is requested that these are included in studies for European use.
7.2 Technical parameters and implications on spectrum
7.2.1 Current ITU and European Common Allocations
Operation of these devices is assumed according to a provision of the Radio Regulations (RR4.4) that does not require
any new allocation (i.e. on a non-protected basis and causing no harmful interference).
7.2.2 Sharing and compatibility studies (if any) already available
None have presently been carried out.
7.2.3 Sharing and compatibility issues still to be considered
Power levels (10 mW) and bandwidth (25 kHz) are proposed to minimise interference to existing services. However,
the proponents believe that forwarding the present document to CEPT will allow any interference and compatibility
issues to be fully examined.
7.2.4 Transmitter parameters for Telecoil Replacement Service operating
at VHF and UHF frequencies
10 mW for "base station".
If the hearing aid was to use an interactive service this would be below 0,5 mW.
It is requested that a minimum of 6 x 25 KHz channels are made available.
No modulation scheme has been requested as the type of modulation may be prescribed by the sharing studies. It is
suggested that a BEM to allow technology neutrality would come from the sharing studies.
7.2.5 Unwanted emissions
Unwanted emissions are the same as currently specified for these bands.
7.3 Information on relevant standard(s)
After discussions within CEPT, a new work item will be raised to revise EN 300 422 [i.3] to include the Telecoil
Replacement Systems, indicate acceptable parameters, as well as the necessary measurement methods and power limits.
ETSI
14 ETSI TR 102 791 V1.1.1 (2012-05)
8 Radio spectrum requirement and justification
8.1 Justification
After detailed consideration of spectrum up to 2,6 GHz and taking in the points outlined in clause 7 (especially the
world wide requirement), the existing ISM and SRD band have been excluded. Investigation of extending the existing
Telecoil system using advanced modulation techniques have failed to provide a satisfactory or practical answer, the
only spectrum which is worldwide and likely to be compatible with TRS is:
• 156,4875 to 156,5625 and 156,7625 to 156,8375 (T/R 20-08 [i.33], annex 1) Maritime , these could be used in
conjunction with the existing 169 MHz band in Europe and Japan and the 216 MHz band in USA; or
• 960 MHz to 1 164 MHz Band Aeronautical.
During the ETSI consultation stage information on the new proposed SRD bands 870 MHz to 876 MHz and 915 MHz
to 921 MHz has become available and it is requested that these are included in studies for European use.
Bluetooth technology had been extensively investigated for constant audio streaming between the left to right ear, and
vice versa; unfortunately due to the physical size and power consumption this is not a practical option in the present
stage of technology and has therefore been excluded for TRS.
Infrared systems have also been investigated but are unable to provide coverage in large areas.
Hearing aids contribute to patient safety, comfort and enjoyable listening experience. However, real life offers an
incredible richness in different listening environments in some of which even the most sophisticated hearing
instruments show only a limited benefit. Examples of acoustic environments or listening situations where the
performance of conventional hearing instruments can substantially be improved by applying TRS devices are the
following:
• Reverberant environments such as big churches or lecture halls.
• Communication over larger distances e.g. In a lecture or in a classroom.
• Communication on the telephone, especially cell phones.
• Announcement systems in public places such as Airports and train stations.
• Theatre and Concert hall.
• At home with TV, audio systems and door bells.
In these environments the application of assistive listening systems (ALS) with TRS based on wireless communication
technologies offer substantial additional benefits and significantly improves speech intelligibility.
To implement these functions effectively wireless technology and its associated spectrum are required, which will
greatly benefit the hearing impaired. However, compared to wireless hearing aids using inductively coupled
transmission, hearing aids using transmission systems in the VHF and UHF frequency bands have an advantage in
terms of range - allowing them to receive from a source in the same large area or room directly to the hearing aids.
Devices operating in ISM bands in the UHF frequency range additionally profit from globally available unlicensed
spectrum. Therefore, Bluetooth low energy specification or Zigbee, both with their sheer sophisticated protocols have
been considered but found inappropriate, due to the relatively high power consumption leading to unacceptable battery
consumption, life and size. Additionally it was investigated whether any of the designated spectrum under annex 10 of
the CEPT/ERC Recommendation 70-03 [i.1] could allow deployment of wirelessly enabled hearing instruments on a
worldwide basis . Infrared systems have also been investigated but are unable to provide coverage in large arrears.
ETSI
15 ETSI TR 102 791 V1.1.1 (2012-05)
8.2 Requirement
A minimum of 6 x 25 kHz channels operating up to 10 mW in the frequency range:
• 156,4875 to 156,5625 and 156,7625 to 156,8375 (T/R 20-08 [i.33], annex 1) Maritime , these could be used in
conjunction with the existing 169 MHz band in Europe and Japan and the 216 MHz band in USA; or
• 960 MHz to 1 164 MHz Band Aeronautical.
During the ETSI consultation stage information on the new proposed SRD bands 870 MHz to 876 MHz and 915 MHz
to 921 MHz has become available and it is requested that these are included in studies for European use.
In relation to the 870 MHz to 876 MHz and 915 MHz to 921 MHz bands these channels have two services to consider:
• Indoor: short range, which can share with devices such as RFID which are unlikely to be in the same physical
space at the same time.
• Outdoor or Station, and Airport systems: long range 25 meters plus, dedicated channels would be required or
sharing with devices not likely to share the same physical space.
9 Regulations
9.1 Current regulations
9.1.1 Current regulations in Europe for aids for hearing impaired
The existing technologies employed in aids for hearing impaired are operating in various bands as defined in annexes 1,
9 and 10 of the CEPT/ERC Recommendation 70-03 [i.1] as well as in ECC/DEC(05)02 [i.6] and EC Decision
2005/928/EC [i.5] depending on the specific application. Detailed information about
...