Deborah Edwards, MS,CCC-A Dawn Ruley, AuD, CCC-A Advanced FM: Programming & Verification

Overview Introduction to FM FM Verification Procedure Tour of FM Successware

What is a wireless FM system? The teacher or primary speaker wears a wireless microphone called the transmitter. 2. The student wears a miniature FM receiver. This receiver picks up the teacher’s signal. The receiver may be worn alone on the ear or attached to a hearing aid or cochlear implant.

Frequency standard 216 – 217 MHz-band (also called N-Band) North and South America 23 Channels available Received Primary Status from the FCC 2003 for ALD

Why FM? Why does someone need FM if he/she already wears hearing aids?

Three Obstacles for HA Users Background Noise Reverberation Distance from the sound source

FM Priorities Audibility of person wearing FM transmitter/microphone Audibility of self Audibility of others at a variety of distances Lewis and Eiten, Boystown

Examining Priorities Listen for: The relationship of Teacher, HI user and others across FM levels Which segment would you select for best balance of all talkers? a. segment 1 (-6) b. segment 2 (0) c. segment 3 (+10) d. segment 4 (+16) e. segment 5 (+24) Lewis and Eiten, Boystown

SNR at ear level for different technologies No FM Traditional FM Dynamic FM Surrounding Noise (dB SPL) SNR (dB)

No FM Traditional FM Dynamic FM

Speech understanding [%]

No FM Traditional FM Dynamic FM Speech understanding [%]

No FM Traditional FM Dynamic FM Speech understanding [%]

No FM Traditional FM Dynamic FM Speech understanding [%]

No FM Traditional FM Dynamic FM Speech understanding [%]

No FM Traditional FM Dynamic FM Speech understanding [%]

No FM Traditional FM Dynamic FM Speech understanding [%]

Fitting the New Standard Receiver comes standard at +10 dB Default settings are a good beginning, but what comes next…. When should you measure? What should you measure? How should you measure? What should you change? Do you need more equipment?

The Phonak FM Offset Procedure (POP) 1.(FM)M65 2.FM(M)65 3.(FM)HA90 4.FM(M)90  Match target  Transparent with curve 1  Not exceed MPO targets  Not to exceed MPO targets NOTE: (M) means muted environmental mic (FM) means muted FM mic

POP – Sequential Protocol Phonak Offset Protocol To avoid pitfalls both signals must be compressed the same This is quite generally only possible if both signals are of equal amplitude. Phonak FM system set for 10 dB FM advantage is transparent below the kneepoint. Therefore 65 dB input to the FM microphone should result in the same output as 65 dB input into the HI microphone. Use speech signal or broadband (speech shaped) noise as long as individual freq info can be obtained (turn off any feedback management or noise reduction if using swept tones)

Worksheet FM(M)65 curve (dB) * (FM)M65 curve

Run 1: (FM) +HA65 FM receiver in FM+M position

What you see: (FM)+HA Eardrum level dB SPL Predicted level of amplified speech Unamplified conversational speech (+ 12/– 18 dB) Child’s threshold (dB SPL) Amplified speech targets Maximum output targets Normal hearing

Worksheet

Run 2: FM+(HA)65 FM transmitter on HA and receiver set for FM+M and put into sound isolation chamber

What you see: FM+(HA) Eardrum level dB SPL Predicted level of amplified speech (and FM only) Unamplified conversational speech (+ 12/– 18 dB) Child’s threshold (dB SPL) Amplified speech targets Predicted level of amplified FM + M Normal hearing

Worksheet

Worksheet

How to proceed? +/- 2 You are done! > +2Reduce the gain on the FM receiver by the offset value < -2Increase the gain of the FM receiver by the offset value Bonus Question: If you have extra FM advantage, is that just a bonus? Why bother to reprogram?

Run 3: (FM)+M90 HA on in P1- omnidirectional Receiver in FM+M Transmitter muted

What you see: (FM)+HA90 Predicted level of amplified speech Predicted max. output HA Unamplified conversational speech (+ 12/– 18 dB) Child’s threshold (dB SPL) Amplified speech targets Maximum output targets Predicted level of amplified FM + M Frequency Hz 1000 Eardrum level dB SPL Normal hearing

Run 4: FM(HA)90 FM transmitter on/unmuted HA and receiver set for FM+MA and put into sound isolation chamber

What you see: FMHA90 Predicted level of amplified speech Predicted max. output HA Unamplified conversational speech (+ 12/– 18 dB) Child’s threshold (dB SPL) Amplified speech targets Maximum output targets Predicted level of amplified FM + M Frequency Hz 1000 Eardrum level dB SPL Predicted max. output FM Normal hearing

Why change FM Gain Levels? Achieve transparency Patient complaint Reduced benefit Hearing Loss Consideration Age Consideration

Resources FM Successware 4.3 POP Procedure found in FM Successware 4.3 – Guidelines

Thank you