FM, T-Coil, and ALD Tips
Harmony BTE
What is an FM (frequency modulated) system?
FM is a wireless communication technology commonly used in the classroom to overcome the adverse effects of distance and competing noise in communication situations. Using an FM system in difficult listening situations makes communication easier because regardless of the distance between the teacher and the student, the signal is delivered directly to the FM receiver at a consistent volume level.
An FM system consists of two parts: a transmitter worn by a speaker and a receiver worn by the implant recipient. The transmitter picks up the speaker’s voice through a microphone and sends it wirelessly via radio waves directly to the implant recipient’s FM receiver. The FM receiver then sends the speaker’s voice directly to the implant recipient for listening. For people who use cochlear implants, the FM receiver transmits the speaker’s voice directly to the recipient’s sound processor.
Both the transmitter and receiver must be tuned to the same channel. Receivers will capture the signal of the closest transmitter using the matching channel, rejecting other weaker signals.
Basic FM Terminology
Audio Mixing
Audio Mixing allows the speech processor microphone to remain on when the speech processor is connected to an FM system. This is important because it determines whether the individual will be able to hear his/her own voice and sounds around him in addition to the speaker’s voice transmitted through the FM system. Below is an explanation of different mixing ratios. You will need to check with your programming audiologist or parent to determine what mixing ratios are available on the speech processor.
Audio-Mixing Ratios
- 50/50 - Sound from the sound processor microphone and sound from the FM system are equal.
- 30/70- The FM signal is louder than the signal from the sound processor microphone.
- Aux Only - The sound processor microphone is deactivated. The FM signal is the only sound the student will hear.
- Mic Only -The FM system will not deliver sound information to the sound processor. The only sound the student will hear is from the sound processor microphone.
Connect (wireless FM) EarhookAn earhook option for the Harmony Processor that provides cable-free access to the Phonak MicroLink MLxS, the most commonly used advanced miniaturized FM receiver. With a separate power source, the device is designed to provide reliable FM reception without compromising regular power consumption.
Location where the FM system connects with the sound processor.
Harmony Processors have a 3.5 mm auxiliary input jack on the end of the Direct Connect Cable.
Using the Phonak Microlink MLxS with the iconnect
- Verify the MLxS is in the off position (open dot position).
- Attach the MLxS to the iConnect.
- Be sure to line up the thicker pin with the wider socket hole (figure 1).
- Attach the iConnect to the Harmony Processor.
- Align the iConnect with the Harmony.
- Gently push the iConnect straight on until it snaps into place.
- Turn on the FM transmitter first, then the MLxS, and finally connect the battery to the Harmony Processor.
- Use the one dot setting for the MLxS (figure 2).
- Verify that the Harmony program switch is set to a program using audio mixing.
- A 50/50 or 30/70 audio mixing ratio is recommended for use in the classroom.
- To remove the iConnect, first turn off the MLxS then turn the iConnect Earhook slightly to the side until it pops off.

Figure 1. Attach the MLxS to the iConnect. Figure 2. Turn on the MLxS.
iConnect Battery
The iConnect uses a standard size 10 battery. To replace the battery, open the iConnect battery compartment. Do not use excessive force when handling the battery compartment. To avoid unnecessary battery depletion remove the battery from the iConnect when it is not in use.
WARNING: Batteries are toxic when swallowed. Keep them out of reach of young children. If batteries are swallowed, please seek immediate medical attention.
Adapters
There are two different types of adapters: Plug size and signal type
Plug size adapters allow you to connect to an input jack that is not the right size for the plug.

Signal type adapters allow you to convert a mono signal to a stereo one, or convert a stereo signal to a mono one.
MONO - describes a system where the left and right channels are combined.
STEREO - describes a system with an independent left and right channel.
Mono and stereo plugs can be identified by the number of rings or bands on the plug tip.
Mono plugs have only one ring, and stereo plugs have two rings.
The Harmony Sound Processor accepts stereo signals. In most cases, an adapter is not needed. However, if poor sound quality is reported, the appropriate adapter may be used. You can purchase both types of adapters at an electronics store. If you are unsure whether you need to use this type of adapter, contact Advanced Bionics.
FM Adapter Cable (patch cable)
The adapter cable is a special cable used to connect the FM receiver to the implant recipient’s sound processor. FM adapter cables are specific to the particular FM system and sound processor you are using. Most companies that manufacture FM systems make specific FM adapter cables for the different sound processors.
Check with implant recipient’s audiologist to determine if the correct FM adapter cable has been ordered. You can also order the FM adapter cable directly from the appropriate FM manufacturer. If you are not sure which FM adapter cable your student should use with their sound processor, contact the FM manufacturer or Advanced Bionics.
Instructions
Connecting the FM System and the Harmony Processor
- Ensure that you have obtained the appropriate FM adaptor cable (as applicable).
- Ensure that the FM system is functioning appropriately by listening to the FM system with walkman-style earphones or a desktop speaker and according to the FM manufacturer’s recommendations.
- Keeping the FM system in the off position and the battery removed from the Harmony Processor, connect the speech processor and FM receiver through the auxiliary input jack.
- Set any gain, output, or tone controls on the FM receiver per the audiologist or FM manufacturer’s recommendations (as applicable).
- Ensure that the volume control on the FM receiver and the volume dial on the Harmony Processor are both set to the minimum setting.
- In this order: 1) Turn on the FM transmitter and then FM receiver and 2) connect the battery to the Harmony Processor. (*Note: It is extremely important that you turn on the equipment in the proper order to prevent the user from hearing any loud or annoying sounds.)
- Gradually increase the Harmony Processor volume to the everyday setting or as specified by the recipient’s audiologist.
- Gradually increase the volume on the FM receiver to a comfortable listening level or as specified by the audiologist or the FM manufacturer.
- Complete a Listening Check:
- Administer a listening task that you know the user can perform above chance such as the Ling Six sound test, responses to name, or common phrases/questions.
- Perform these tasks in an auditory-only condition and in close proximity to the user.
- Repeat the task at a distance of several meters noting that no changes in performance are observed with the FM in quiet.
- Tasks can also be repeated in noise to assess the effects of the cochlear implant and FM.
Troubleshooting Personal FM Systems
Keep in mind you are working with two separate systems, an FM system and a cochlear implant sound processor. The best way to complete troubleshooting is to begin by separating the two systems.
Troubleshoot the FM System
- Disconnect the FM system from the recipient’s sound processor.
- Verify that the FM system is working by listening to the FM system.
- If the FM system is not working, complete troubleshooting for the FM system as recommended by the FM manufacturer.
- Here are some questions to ask:
- Are the FM transmitter and receiver on the same channel?
- Are the cables on the FM transmitter or receiver frayed or kinked?
- Has the transmitting distance been exceeded?
- Do the batteries for the FM transmitter and/or receiver need to be replaced?
- Is the microphone on the transmitter working?
- Are the FM settings set appropriately?
- If you are unsure how to troubleshoot the FM system, call the FM manufacturer directly.
Troubleshoot the Sound Processor
- If the student cannot hear with the cochlear implant alone, complete troubleshooting for the sound processor as directed by the Harmony Processor User Guide.
- If you are still unsure how to troubleshoot the Harmony Processor, call Advanced Bionics or the implant recipient’s cochlear implant center.
- Once you have verified that both systems are working properly on their own, complete the following steps for the specific situations below.
- Student cannot hear the FM signal
- Verify that you are using the proper FM adapter cable for the FM system and sound processor.
- Verify that you are using a sound processor program that has audio mixing enabled. (The selected program should not be set to microphone only.)
- Replace the FM adapter cable.
Noise, interference, or distortion
- Verify that you are using the proper FM adapter cable for the FM system and sound processor.
- Increase the physical distance between the FM receiver and sound processor when using a body-worn FM receiver.
- Ensure the headpiece cable and FM cable are not intertwined.
- Ensure that the transmission range is not exceeded. The broadcast range between FM transmitters and receivers may begin to break up at distances >20 meters.
- Observe areas in the classroom or other environments that can cause dead spots in transmission by completing a listening check with the FM system. Avoid seating the student in any problem areas.
- Reduce the volume or gain of the FM receiver.
- Try a different FM channel.
- Replace the FM adapter cable.
Listening responses poorer than normal
- Verify that you are using the proper FM adapter cable for the FM system and sound processor.
- Verify that you are using a sound processor program that has audio-mixing enabled. (The recipient’s program should not be set to microphone only.)
- Replace the FM adapter cable.
Recipient cannot hear their own voice or other people’s voices
- Verify that you are using a sound processor program that has audio-mixing enabled. (The recipient’s program should not be set to auxiliary only.)
- Contact Advanced Bionics for assistance.
Troubleshooting iConnect™ Adapter and the Phonak MLxS FM Receiver
No Sound
- Are your connections secure?
- Did you try another PowerCel Another size-10 battery?*
- Is the volume control set appropriately on the Harmony Processor?
- Did you troubleshoot both the Harmony Processor and MLxS systems independently? (i.e. using the amplified speaker for the Harmony Processor and Headset FM Checker for the MLxS)
No FM Signal
- Are your connections secure?
- Is the MLxS turned on?
- Did you try another size-10 battery?*
- Are you using an appropriate audio-mixing setting/program?
- Are the MLxS and FM transmitter operating on the same frequency? (i.e., did you synchronize the system if applicable)
- Is the transmitter turned on and at the recommended settings?
- Is the battery in the transmitter charged?
- Is the speaker wearing the transmitter properly? (i.e., microphone distance from mouth is 4 to 6 inches)
- Are you within an appropriate transmission range between the FM receiver and transmitter? (For example, the system may lose transmission beyond 40 feet indoors and 120 feet outdoors)
- Are the iConnect adapter battery contacts and the MLxS pins free of dirt and contamination? Use a hearing aid brush to clean them.
Noise, Static or Distortion
- Are your connections secure?
- Did you try another size 10 battery?*
- Is the transmitter turned on and at the recommended setting? Is the battery working?
- Is the speaker wearing the transmitter properly? (i.e., microphone not rubbing on clothes, distance from mouth is 4 to 6 inches)
- Are the Harmony Processor and MLxS controls set appropriately?
- Did you try a different transmitting frequency?
- Did you troubleshoot both the Harmony Processor and MLxS systems independently? (i.e., using the amplified speaker for the Harmony processor and Headset FM Checker for the MLxS)
- Are the iConnect adapter battery contacts and the MLxS pins free of dirt and contamination? Use a hearing aid brush to clean them.
Interference
- Did you evaluate the room for sources of potential interference? (e.g., metal cabinets, fluorescent lights, etc.)
- Did you try a different transmitting frequency?
- Are you within an appropriate transmission range between the FM receiver and transmitter? (For example, the system may lose transmission beyond 40 feet indoors and 120 feet outdoors)
- Did you check your connections, batteries and settings?
Recipient Cannot Hear Own Voice or Other’s Voices
- Are you using the appropriate audio-mixing?
- Are your controls set properly?
- Did you check for any of the above complaints? (noise, interference, dead battery, etc.)
Listening Responses Poorer With FM or Poorer Than Normal
- Did you check your connections, batteries and system settings? (i.e., Are you using the 1-dot setting on the MLxS?)
- Did you test both the Harmony Processor and MLxS systems independently to ensure that both are working appropriately?
- Did you check for any of the above complaints? (noise, interference, etc.)
- Are you using the appropriate mixing ratio? (Recommended default is 50/50.)
- If yes, did you try increasing the gain on the MLxS and reassessing performance?
- If yes, did you try a 30/70 mixing ratio?
* NOTE: A hearing aid battery tester is a simple, and inexpensive tool to have on hand to ensure that a good battery is being used in the iConnect™ Adapter.
The following vendors are a reference source for customized FM adapter cables
In those cases where the FM manufacturer does not make FM adapter cables compatible with the implant recipient’s sound processor, contact a vendor to have the appropriate FM adapter cable specially made.
Audex
710 Standard Street
Longview, TX 75604
(800) 237-0716
(800) AUDEX-74 Fax
www.audex.com
Hearing Loss Help Company
Curtis Dickenson
75 Townsend Street
First Floor, Left
Worcester, MA 01609-1979
(508) 755-1120
(508) 755-1120 Fax (call first before sending a fax)
info@hearing-loss-help-co.com
www.hearing-loss-help-co.com
FM Manufacturer Resource Info
Below is information on commonly used FM systems.
For information on a system not listed, please contact Advanced Bionics.
Phonak

FM Receiver: MLXs
FM Interface: MLCIs
FM adapter cable: Obtain from Phonak - MLCI-0013 (for use with Harmony BTE)
Company Contact Information:
Phonak, Inc., USA
(630) 821-5000
(800) 777-7333
info@phonak.com
www.phonak-us.com
Sonovation

FM System: AVR Logicom CI
FM adapter cable: None needed. The Logicom plugs directly into the Direct Connect Cable
Company Contact Information:
Sonovation
(952) 934-3111
(800) 462-8336
Customer Support: sonosupport@avrsono.com
Clinical Support: sonoclinic@avrsono.com
www.avrsono.com
Phonic Ear

FM system: Solaris
FM adapter cable: Obtain from Phonic Ear AT0743 (For use with Harmony BTE)
Company Contact Information:
Phonic Ear
(800) 227-0735 (US)
(800) 263-8700 (CN)
www.phonicear.com
Telecoils and Induction Loop Systems
Telecoils has been used in hearing aids for quite some time, especially in Europe. In England they are mandatory for public buildings. So what are they?
It is a very simple system. Basically, a wire or loop is used at the same time as a speaker system. This means someone talks into a microphone that sends its signal to two different places—to an amplifier with regular speakers and to single-wire loop located in the room. The wire is called an induction loop, which sends a signal that is picked up by the telecoil inside a hearing aid or a cochlear implant processor. You must have a telecoil (t-coil) to pick up the signal. You receive this signal at the same time as the regular sound coming from the speakers.
Traditional tabletop phones are required to be hearing-aid (t-coil) compatible by having built-in inductive loops; however, some but not all cordless or cell phones are t-coil compatible.
There are many advantages to a t-coil and loop system, as well as some disadvantages. They work well for things like classrooms, churches, and office situations.
For more information on Loop Systems, visit www.HearingLoop.Org
Harmony Built-in Internal Telecoil (T-Coil)
The built-in T-Coil provides you with wireless access to inductive loop environments. Ask your audiologist to create and optimize a program with the built-in T-Coil enabled while visiting your implant programming center. Your audiologist will assign this dedicated program to one of the switch positions on the Harmony Processor.
When ready to use the T-Coil, select the assigned program switch position with the T-Coil enabled. You may need to adjust your position or the orientation of your body while using the internal T-Coil to optimize the T-Coil reception.
Harmony Processor Direct Connect Earhook With T-Coil Accessory
The Telecoil Adaptor (#CI-5750) provides access to inductive loop environments. It is an accessory option that simply snaps on to the Direct Connect Earhook.
You may find using the T-Coil Adapter to be a convenient option if you do not currently have a program position assigned to access the Harmony built-in T-Coil or if you prefer not to have a dedicated position programmed exclusively for use with the built-in T-Coil.
Use a program setting with audio mixing assigned for use with the Direct Connect Earhook as instructed by your audiologist. When you connect the T-Coil Adaptor onto your Direct Connect Earhook, you are ready to pick up the signal from an induction loop system. Rotate the T-Coil Adapter as needed to optimize sound quality while listening through the T-Coil.
Direct Connect Earhook with T-Coil
Harmony with T-Coil on Direct ConnectEarhook
Audio Mixing
Audio mixing options are available on the Harmony Sound Processor. Audio mixing allows the microphone on the Harmony Processor to remain active when connected directly to a T-Coil, or any other external audio input through the Direct Connect Earhook or iConnect FM Adapter.
You may need to see your audiologist to set up a program with the correct audio mixing for connecting through your Direct Connect System to Assistive Listening Devices (ALDs).
If you are directly connecting to an ALD with a cable or adapter, you may want your audiologist to set up an audio mixing ratio of 100% auxiliary so that you hear only the sounds from that device.
Assistive Listening Devices Online Vendors
Below is a partial list of assistive technology vendors. Additional vendors can be found by searching “assistive listening devices” on the Internet.*
Clarity Products www.clarityproducts.com
HARC Accessolutions www.hacofamerica.com
Beyond Hearing Aids www.beyondhearingaids.com
Harris Communications www.harriscomm.com
Sound Clarity www.soundclarity.com
Audex www.audex.com
*Advanced Bionics does not support any products purchased through an outside vendor.
Have more questions?
Connect to a MentorTalk to a recipient
Visit Hearing JourneyJoin the online community
Contact the Bionic Ear AssociationReach our support network