The Benefits of Nonlinear Frequency Compression for People with Mild Hearing Loss

Nonlinear frequency compression compensates for hearing loss in frequency ranges where traditional amplification on its own does not provide sufficient benefit. The effectiveness of Phonak’s proprietary nonlinear frequency compression algorithm, SoundRecover, has been documented for more significant degrees hearing loss (Simpson, Hersbach & McDermott, 2005, 2006; Nyffeler, 2008). The purpose of this study was to test whether SoundRecover provides sufficient benefit for people with mild to moderate hearing loss. Sufficient benefit is defined as whether the person can more easily recognize quiet, high frequency sounds. This study focused particularly on the /s/ sound. To measure consonant identification, a special test, the Adaptive Logatom Test, was designed that is sufficiently sensitive for cases of mild and moderate hearing loss (i.e. phonemes cannot be discerned on the basis of word or sentence context). The Adaptive Logatom Test was administered using adaptive control of the presentation level, and the respective identification thresholds of various consonants in nonsense syllables (logatoms) were recorded. The identification threshold of the /s/ sound clearly improved with SoundRecover. In addition, subjects reported that listening with SoundRecover was more pleasant than listening without it. A summary of this study was previously published in Phonak Field Study News (April 2009). This article provides the entire study, results and discussion

Entwicklung eines 'Hoerbildverfahrens' zur praxisgerechten Ueberpruefung und Optimierung von Hoergeraeten mit alltagsnahen Hoersituationen Abschlussbericht

The 'Hoerbildverfahren' was developed to supplement the diagnostic procedures of frequency specific speech audiometry and audible field audiometry. It is used to evaluate and optimize hearing rehabilitation. The new procedure is based on stereophonic recordings of everyday hearing situations. The adequate transmission of their physical and psychophysical characteristics by the hearing aid is central to the success of the fitting. Based on these recordings hearing dimensions (e.g. sharpness, reverberation, overall quality) were determined which allow the reliable evaluation of the transmission quality. In addition, a presentation and scaling method were developed which can be used for the fitting of hearing aids. The procedure also allows the judgement of global speech intelligibility for everyday dialogues with background noise of varying loudness and the effort required to understand speech. A first evaluation of the procedure tool place in a field study with three acousticians and 25 subjects. The subjects suffered from sensorineural hearing loss (30-50 dB HL below 1 kHz, high freqency slope to a maximum of 70 dB HL at 4 kHz). We were able to show that the initial fitting of the hearing aid on the basis of the audible field audiometry resulted in good transmission quality which was enhanced by the fine tuning using the 'Hoerbildverfahren'. Furthermore, the fine tuning increased speech intelligibility in moderate background noise (car interior noise) and reduced the effort required for understanding speech. (orig.)SIGLEAvailable from TIB Hannover: F97B2257+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman