1 / 18

Importance of FM Systems and Product Overview

Importance of FM Systems and Product Overview. Evert Dijkstra, Phonak Communications, Murten, Switzerland. Outline. Introduction FM systems State-of-the art FM systems for hearing impaired children, adults, and CI recipients

gwyn
Download Presentation

Importance of FM Systems and Product Overview

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Importance of FM Systems and Product Overview Evert Dijkstra, Phonak Communications, Murten, Switzerland

  2. Outline • Introduction FM systems • State-of-the art FM systems for hearing impaired children, adults, and CI recipients • State-of-the art FM systems for children with Auditory Processing Disorders, Attention Deficit and Learning Disabilities • Conclusions

  3. Introduction Three factors deteriorate the Signal-to-Noise ratio and therefore the speech perception • Noise • Reverberation • Distance

  4. Noise Many of our daily activities are happening in a noisy environment

  5. HL and additionally required SNR Necessary SNR for 50% recognition of sentences (adults) Average hearing loss in dB Killion, 1997 Signal-to-Noise ratio in dB (Ref.: normal hearing)

  6. Infants 8-11 months Difference in SNR between children and adults 1.0 0.9 0.8 0.7 0.6 0.5 0.4 • Curves compare adult and infant sound discrimination in noise - normal hearing • Children are at a greater • disadvantage than adults • Noise has greatest impact on children during the period of language acquisition Proportion correct -16 -8 0 8 16 24 Signal-to-Noise Ratio (dB) Adults Nozza et al., 1990

  7. Echo All rooms cause echos; depending on building materials some more than others

  8. Field Study Helfer & Wilber • Comparison scores for different ages • With S/R = 10 dB • Words with/without meanings

  9. Meaningful Words

  10. Meaningless words

  11. Recordings: (www.utdallas.edu/~thib) Distance dB 80 70 60 50 40 Noise floor 4 6 0 2 1 Distance (Meter)

  12. Effect of distance on normal hearing children and adults Normal hearing children and adults • All children are at a disadvantage when listening to a distant speaker or in background noise • Hearing impaired children have an even greater disadvantage in these environments Word recognition up-close in quiet (1.8 m) Age Group Word recognition with distance &noise (7 m) 67% 4 years 88.3% 5 years 94.3% 84% 6 years 98% 86.7% Adult 99.3% 97.0% Adapted from Johnson 1996

  13. Available technologies? • Key Question: Are there technologies that can simultaneously restore the required SNR, avoid the impact of echo’s and overcome the distance ? • Answer today: Only one, I.e. FM technology • Answer tomorrow: Most likely only one, I.e. FM technology

  14. Principle of FM FM

  15. Fieldstudy with 48 adults Source: Valente, 2002

  16. Settings for fieldstudy SuperZoom (2 directional microphones) Zoom (1 directional microphone) Wide-Angle (1 omnidirectional microphone) TX3 Claro-FM

  17. 5.9 2.3 1.8 6.5 3.2 2.1 (SD) 4.3 dB Source: Valente, 2002

  18. MicroLink MLx Evolution of FM receivers Focus:Integration Focus:Flexibility Focus:Standardization Focus:Miniaturization Focus:Robustness MLxS Body-worn iLink 1997 1999 2003 2005

More Related