European Archives of Oto-Rhino-Laryngology

, Volume 267, Issue 7, pp 1045–1053 | Cite as

Advantages of a non-linear frequency compression algorithm in noise

  • Andrea Bohnert
  • Myriel Nyffeler
  • Annerose Keilmann


A multichannel non-linear frequency compression algorithm was evaluated in comparison to conventional amplification hearing aids using a test of speech understanding in noise (Oldenburger Satztest—OLSA) and subjective questionnaires. The new algorithm compresses frequencies above a pre-calculated cut off frequency and shifts them to a lower frequency range, thereby providing high-frequency audibility. Low-frequencies, below the compression cut off frequency, are amplified normally. This algorithm is called SoundRecover (SR). In this study, 11 experienced hearing aid users with a severe to profound sensorineural hearing loss were tested. Seven subjects showed enhanced levels of understanding in noise (OLSA) using frequency compression. However, 4 out of the 11 subjects could not benefit from the high-frequency gain. Evaluation using questionnaires demonstrated an increased level of satisfaction after 2 months of experimental devices wearing (p = 0.08) and after 4 months of wearing (p = 0.09), respectively, compared to conventional hearing instruments.


Profound hearing loss High-frequency audibility Multichannel non-linear frequency compression algorithm Speech understanding in noise Subjective questionnaires 



The study has been approved by the Human Research Ethics Committee of Mainz and the use of human subjects was in accordance with the “Guiding principles for research involving human or animals subjects”. The authors are extremely grateful to the thoughtful comments of the Reviewer. The present study was supported by Phonak AG, Stäfa. The authors declare that there is no conflict of interest. They confirm independence from the sponsor; the content of the article has not been influenced by the sponsor.


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Andrea Bohnert
    • 1
  • Myriel Nyffeler
    • 2
  • Annerose Keilmann
    • 1
  1. 1.Department of ENT and Communication DisordersMainz Medical SchoolMainzGermany
  2. 2.Phonak AGStäfaSwitzerland

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