Markus Landwehr

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The purpose of this study was to examine the effects of altering the fundamental frequency (F0) on perception of prosody and speaker gender in both normal-hearing listeners and cochlear implant (CI) recipients. Tests with natural speech and defined modifications of the F0 were performed, and the resulting changes in perception were measured. Compared to the(More)
Advances in speech coding strategies and electrode array designs for cochlear implants (CIs) predominantly aim at improving speech perception. Current efforts are also directed at transmitting appropriate cues of the fundamental frequency (F0) to the auditory nerve with respect to speech quality, prosody, and music perception. The aim of this study was to(More)
PURPOSE The objective of the study was to investigate the influence of noise (energetic) and speech (energetic plus informational) maskers on the head shadow (HS), squelch (SQ), and binaural summation (SU) effect in bilateral and bimodal cochlear implant (CI) users. METHOD Speech recognition was measured in the presence of either a competing talker or(More)
In clinical practice, an objective method to assess listening effort is still not available. The benefit of such a measure would be to reduce the listening effort in hearing impaired persons by an adequate adaption of their personal hearing aids. In foregoing studies, we have shown that the wavelet phase synchronization stability (WPSS) of auditory late(More)
OBJECTIVES To investigate the discrimination of two isolated spectral timbre cues, spectral centroid (Fc) and spectral irregularity (spIrr), in cochlear implant (CI) listeners. To examine whether the perception of Fc and spIrr changes is related to the perception of loudness and pitch and the identification of musical instruments. METHODS Stimuli were(More)
PURPOSE The objective of the study was to investigate the influence of bimodal stimulation upon hearing ability for speech recognition in the presence of a single competing talker. METHOD Speech recognition was measured in 3 listening conditions: hearing aid (HA) alone, cochlear implant (CI) alone, and both devices together (CI + HA). To examine the use(More)
Mit dem Begriff „Informational Masking“ (IM) wird die Beeinträchtigung des Sprachverstehens (SV) bei konkurrierenden Sprachsignalen bezeichnet. Nachteilig wirken sich nicht nur spektrale Verdeckungseffekte, sondern auch die zusätzliche Information durch den Störsprecher aus. Für Kochleaimplantat- (CI-)Träger ist eine adäquate Trennung konkurrierender(More)
The corruption of intonation contours has detrimental effects on sentence-based speech recognition in normal-hearing listeners Binns and Culling [(2007). J. Acoust. Soc. Am. 122, 1765-1776]. This paper examines whether this finding also applies to cochlear implant (CI) recipients. The subjects' F0-discrimination and speech perception in the presence of(More)
OBJECTIVES Sentence stress is a vital attribute of speech since it indicates the importance of specific words within an utterance. Basic acoustic correlates of stress are syllable duration, intensity, and fundamental frequency (F0). Objectives of the study were to determine cochlear implant (CI) users' perception of the acoustic correlates and to uncover(More)
BACKGROUND Prosody reflects rhythmic and melodic aspects in speech and is one of the quality measures that shows--apart from pure speech understanding--a rising interest in the assessment of technical hearing aids, especially of cochlear implants. At present, there is no adequate test battery for the German speaking population. The test battery presented in(More)