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Untersuchungen zum Einfluss des Mischungsverhältnisses der FM-Anlage auf das Sprachverständnis im Störschall bei CI-Patienten (Influence of an FM system's mixing ratio on speech understanding in noise in cochlear implant patients)

From https://assistivelisteningknowledgebase.org/evidence/hey-2009/ · record checked 9 October 2026

  • Hey M, Anft D, Hocke T, Scholz G, Hessel H, Begall K
  • Laryngo-Rhino-Otologie 88(5):315-321 (Thieme; in German)

Independent (first author at the ENT department of AMEOS Klinikum St. Salvator, Halberstadt; the co-authors' affiliations and any funding statement are in the German full text, which could not be read; the implants were Cochlear's and the FM system Phonak's)

Summary

Measured how the balance between FM and microphone input changes speech understanding in noise for adult cochlear implant users, when the talker wears the FM transmitter and when another talker does not.

Key findings

  • Seventeen postlingually deafened adults with Cochlear Freedom implant systems used a Phonak MicroLink FM receiver with a Campus transmitter, and eight normal-hearing adults served as controls. Speech reception thresholds were measured in noise with the adaptive Oldenburg sentence test, in a set-up simulating a classroom.
  • Without FM, the median threshold was 1.6 dB for the implant users and -13 dB for the normal-hearing listeners.
  • When the talker wore the FM transmitter ("teacher is talking"), understanding improved as the FM share of the mix rose; at a 3:1 ratio of FM to microphone, the threshold was 15 dB better than without FM.
  • When another talker without the transmitter spoke ("pupil is talking"), understanding stayed nearly the same at every mixing ratio, with no statistically significant difference from listening without FM.
  • The authors found no single FM setting that was best for both situations and suggest different settings for different listening conditions.

Limits

Read from the English abstract only; the German full text could not be read. Published online on 22 December 2008, in the May 2009 issue. Personal FM in a simulated classroom with one maker's implants of 2008: evidence about the input path and the mix, not a venue system.

Read the original

doi.org/10.1055/s-0028-1100382

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Cite this source

Hey M, Anft D, Hocke T, Scholz G, Hessel H, Begall K. Untersuchungen zum Einfluss des Mischungsverhältnisses der FM-Anlage auf das Sprachverständnis im Störschall bei CI-Patienten (Influence of an FM system's mixing ratio on speech understanding in noise in cochlear implant patients). Laryngo-Rhino-Otologie 88(5):315-321 (Thieme; in German). May 2009. https://doi.org/10.1055/s-0028-1100382 (accessed 9 October 2026).

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