1. The benefit of using the Microlink MLx and MLxS FM radio aid systems, over distance and in noise, with the Nucleus ESPrit 3G speech processor
Sarah Flynn and Elizabeth Wood
South of England Cochlear Implant Centre
University of Southampton
Paula Greenham Cochlear Europe Ltd
Thank you for giving me the opportunity to update you on our experiences with the use of FM systems and cochlear implants.
I am going to give a little background about different systems and the research we have done so far, our current project and what is being planned for the near future

2. South of England Cochlear Implant Centre University of Southampton
Acknowledgements
Mark Lutman
South of England Cochlear Implant Centre
University of Southampton
Cochlear Europe Ltd
Phonak UK

3. How FM radio aids help the Signal to Noise ratio
Reduce speaker to ear distance
Desired sound predominates over background noise

4. Research rationale Older children and adults for sound quality rating
Word discrimination testing with McCormick Automated Toy Discrimination Test (ATT)
Tested in pink noise with noise behind subject to simulate classroom conditions
Tested at 10 metres from the radio aid transmitter to simulate distance from speaker
Trials with different microphone options
Trials with different gains for MLxS / Campus S
No change to processor sensitivity setting

5. Phonak Microlink MLxS

6. Microphone options Handy mic with MLx Campus S with MLx In noise
Omni setting same or better than zoom (0 and 4dB difference) or superzoom
(0 and 5dB difference)
Over distance
Omni slightly better than zoom (2 and 3dB difference) and better than superzoom (10 and 7dB difference)
Campus S with MLx
In noise
Omni microphone setting better than directional (3.3 and 2.5 dB difference)
Over distance
Omni microphone setting better than directional (5 and 9dB difference)

7. ATT scores at 10 metres with different MLxS gains

8. Signal to noise ratio benefit for different MLxS gains

9. MLxS with the 3G
Mean results showed that MLxS receivers with gains of 10, 16 and 20 gave a significant improvement in noise (all p<0.03)
At 10 metres, a gain of 16 was significantly better than 10 (p<0.01), but 20 gave marginal benefit over 16 (p=0.05)
4/8 subjects said the 10 gain MLxS was too quiet to listen to for a long time
3/7 subjects said the 20 gain MLxS was too loud to listen to for a long time
The best sound quality rating was for 10 gain (87%) and the worst was for 20 gain (67%)

10. Conclusions
Microlink MLx and MLxS radio aids can be used with cochlear implants
MicroLink MLx
significantly lower speech discrimination scores at 10m than MLxS (p<0.001)
not significantly different than MLxS in noise (p>0.07)
Microlink MLxS –
Gain of between 10 and 16dB appropriate for most users but one level is unlikely to suit all users
Probable saturation at >16
Need for patient feedback and good communication between clinic and education professionals

11. References
McCormick B (1977)The Toy Discrimination Test: an aid for screening the hearing of children above the mental age of 2 years. Public Health London 91, 67-69
Ousey J, Sheppard S, Twomey T and Palmer A (1989) The IHR /McCormick Toy Discrimination Test - description and initial evaluation. British Journal of Audiology 23,
Wood E, Flynn S, Eyles J and Greenham P (2003) The benefit of using an FM radio aid over distance and in noise, with the Nucleus Esprit 3G speech processor. Poster at 9th Symposium on Cochlear Implants, Washington DC.
Wood E, Flynn S and Greenham P (2003) The benefit of using an FM radio aid over distance and in noise, with the Nucleus Esprit 3G speech processor. Poster at ACCESS Conference, Chicago.
Handouts are attached of posters of some of these