FM, T-Coil, and ALD Tips

CII and Platinum 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.

Auxiliary Input Jack (of the sound processor)
Location where the FM system connects with the sound processor.

CII BTE and Platinum BTE Processors have a 3.5 mm auxiliary input jack on the end of the Auxiliary Audio Earhook Cable.

BTE Sound Processor
CII BTE/Platinum BTE

Attach the BTE Auxiliary Audio Earhook to connect the FM system.

The Auxiliary Audio Earhook Cable is 36 inches long.

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 CII or Platinum BTE 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.

Step by Step Instructions

Connecting the FM System and the CII / Platinum BTE Processor

1. Ensure that you have obtained the appropriate FM adapter cable (as applicable).
2. 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.
3. Keeping the FM system in the off position and the battery removed from the BTE processor, connect the speech processor and FM receiver through the auxiliary input jack.
4. Set any gain, output, or tone controls on the FM receiver per the audiologist or FM manufacturer’s recommendations (as applicable).
5. Ensure that the volume control on the FM receiver and the volume on the BTE processor are both set to the minimum setting.
   1. Administer a listening task that you know the recipient can perform above chance such as the Ling six sound test, responses to name, or common phrases/questions.
   2. Perform these tasks in an auditory-only condition and in close proximity to the recipient.
   3. Repeat the task at a distance of several meters, noting that no changes in performance are observed with the FM in quiet.
   4. Tasks can also be repeated in noise to assess the effects of the cochlear implant and FM.
6. In this order, turn on the FM transmitter and FM receiver and connect the battery to the BTE Processor. (*Note: It is extremely important that you turn on the equipment in the proper order to prevent the recipient from hearing any loud or annoying sounds.)
7. Gradually increase the BTE Processor volume to the everyday setting or as  specified by the recipient’s audiologist.
8. Gradually increase the volume on the FM receiver to a comfortable listening level or as specified by the audiologist or the FM manufacturer.
9. Complete a Listening Check:

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 BTE 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 BTE Processor User Guide.
• If you are still unsure how to troubleshoot the CII BTE and Platinum BTE Processors, 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 BTE 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.

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 CII/Platinum BTE)

Company Contact Information:

Phonak, Inc., USA
(630) 821-5000
(800) 777-7333
info@phonak.com
www.phonak-us.com
 
Sonavation

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 CII/Platinum BTE)

Company Contact Information:

Phonic Ear
(800) 227-0735 (US)
(800) 263-8700 (CN)
www.phonicear.com

Telecoils and Induction Loop Systems
Telecoils have 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 is used at the same time as a speaker system. This wire is called a loop. This means someone talks into a microphone that sends its signal to two different places—to an amplifier with regular speakers and to a single-wire loop.

The wire is called an induction loop, which puts out 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 locations like classrooms, churches, and office situations.

For more information on Loop Systems, visit www.HearingLoop.Org

Audio Mixing
Audio mixing options are available on the CII BTE and Platinum BTE Sound Processors.  Audio mixing allows the microphone on the BTE Processor to remain active when connected directly to a t-coil, or any other external audio input through the Auxiliary Audio Input Cable. You may need to see your audiologist to set up a program with the correct audio mixing for connecting through your Auxiliary Audio Input Cable 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.

For more information, please contact the Bionic Ear Association at: hear@advancedbionics.com.

The Bionic Ear Association (BEA) is a FREE membership organization that supports you and your family.

Whether you are considering cochlear implants or currently use them, the BEA provides resources, information and programs to support you along your Journey to Sound. Join today!