Einleitung Das Sprachverstehen im Störgeräusch bereitet Nutzern von Cochlea-Implantaten (CI) häufig deutlich mehr Schwierigkeiten als Normalhörenden (NH). Zusätzlich wird über eine erhöhte Höranstrengung berichtet. In der vorliegenden Studie wurde der Einfluss verschiedener Signalvorverarbeitungen in CI-Systemen auf das Sprachverstehen und die Höranstrengung im Störgeräusch untersucht.

Objectives: The aim of this study was to compare the impact of reverberation on sound localization accuracy and speech perception in noise between subjects with single-sided deafness using a cochlear implant (SSD-CI) and a normal-hearing control group. Methods: Nine SSD-CI subjects and 21 normal-hearing subjects participated in the study. In Experiment 1, the sound localization accuracy was measured with and without reverberation. In Experiment 2, speech reception thresholds were determined with four asymmetrically arranged noise sources in free-field and in reverberation. For the realization of reverberation, a room simulation system comprising of 128 loudspeakers was used. Results: No significant impact of reverberation was found on the sound localization accuracy of the SSD-CI subjects (free-field: 12.6 degrees, reverberation: 11.9 degrees), whereas the normal-hearing subjects performed significantly worse in reverberation (free-field: 1.8 degrees, reverberation: 3.3 degrees). Both subject groups experienced significantly deteriorated speech reception thresholds due to reverberation (p(SSD-CI) = 0.008, p(NH) < 0.001). Mean speech reception thresholds in the SSD-CI subjects were -9.7 dB SNR (free-field) and -4.2 dB SNR (reverberation) and a median individual decrease of 5.7 dB SNR in reverberation. Mean speech reception thresholds in the normal-hearing group were -14.0 dB SNR (free-field) and -10.3 dB SNR (reverberation). Conclusion: A strong deterioration of sound localization accuracy due to reverberation did not occur. However, although partial restoration of binaural hearing is assumed in SSD-CI users, the impact of reverberation on speech perception in noise is much stronger compared to normal-hearing.

Introduction Speech perception in noise in cochlear implant (CI) users is often significantly reduced compared to subjects with normal hearing (NH). Furthermore, increased listening effort is reported. In the present study, the impact of different signal preprocessing algorithms in CI systems on speech perception and listening effort in noise was investigated.

Clinical speech perception tests with simple presentation conditions often overestimate the impact of signal preprocessing on speech perception in complex listening environments. A new procedure was developed to assess speech perception in interleaved acoustic environments of different complexity that allows investigation of the impact of an automatic scene classification (ASC) algorithm on speech perception. The procedure was applied in cohorts of normal hearing (NH) controls and uni- and bilateral cochlear implant (CI) users. Speech reception thresholds (SRTs) were measured by means of a matrix sentence test in five acoustic environments that included different noise conditions (amplitude modulated and continuous), two spatial configurations, and reverberation. The acoustic environments were encapsulated in a randomized, mixed order single experimental run. Acoustic room simulation was played back with a loudspeaker auralization setup with 128 loudspeakers. 18 NH, 16 unilateral, and 16 bilateral CI users participated. SRTs were evaluated for each individual acoustic environment and as mean-SRT. Mean-SRTs improved by 2.4 dB signal-to-noise ratio for unilateral and 1.3 dB signal-to-noise ratio for bilateral CI users with activated ASC. Without ASC, the mean-SRT of bilateral CI users was 3.7 dB better than the SRT of unilateral CI users. The mean-SRT indicated significant differences, with NH group performing best and unilateral CI users performing worse with a difference of up to 13 dB compared to NH. The proposed speech test procedure successfully demonstrated that speech perception and benefit with ASC depend on the acoustic environment.

Introduction Speech perception in noise is oftentimes more difficult for cochlear implant (CI) users than for those with normal hearing (NH). In the case of unilateral CI with normal hearing or only mild hearing loss in the opposite ear, speech perception is often described as good up to very good in everyday life, but increased dizziness is reported at the end of the school or work day. The aim of the study was therefore to investigate the listening effort of CI users in noise.

The binaural processing of auditory signals is essential for speech intelligibility in noise and the localization of acoustic signals. Cochlear implants (CI) allow hearing impaired with single sided deafness (SSD) a binaural hearing. In this study the influence of reverberation on the speech understanding in noise and the localization performance of SSD subjects and normal hearings (NH) was analyzed. Five experienced SSD subjects (ᴓ Age: 50 years) and 21 NH (ᴓ Age: 28 years) participated in the study. The tests are performed in an anechoic chamber in a free field condition and with reverberation (room simulation of an auditorium). The mean localization ability was measured for broadband pulsed noise stimuli in the frontal horizontal plane for angles between ± 60°. The speech reception thresholds (SRT) were tested with four time-wise decorrelated noise sources (amplitude modulated white noise) and frontal speech presentation. The median angular error for SSD subjects in free field was 12.1° and for NH 1.8°. There was a wide variation in the localization abilities for the CI subjects. When adding reverberation the speech performance of the SSD subjects decreased significantly from -11.8 dB SNR in free field to -4.8 dB SNR (for NH: -14.0 dB SNR in free field condition and -10.3 in reverberation condition). All SSD subjects showed an appropriate localization performance for daily life. The localization and the speech performance aggravated in the presence of reverberation, especially for the SSD user.

Einleitung Das Sprachverstehen im Störgeräusch bereitet Nutzern von Cochlea-Implantaten (CI) häufig deutlich mehr Schwierigkeiten als Normalhörenden (NH). Bei einseitiger CI-Versorgung mit Normalhörigkeit oder nur geringer Hörminderung im Gegenohr wird das Sprachverstehen im Alltag häufig als gut bis sehr gut beschrieben, am Ende des Schul- oder Arbeitstags aber von einer erhöhten Erschöpfung berichtet. Ziel der Studie war daher die Untersuchung der Höranstrengung von CI-Nutzern im Störgeräusch.

Zur Lokalisation von Schallen und um auch in schwierigen Störgeräuschsituationen Sprache verstehen zu können, ist die Verarbeitung beider Ohrsignale essentiell. Bei Menschen mit einseitiger Taubheit (engl. single-sided deafness, SSD) ermöglicht die Versorgung mit einem Cochlea-Implantat (CI) ein beidohriges Hören. Ziel der Studie war es, den Einfluss von Nachhall auf die Lokalisationsfähigkeit und auf das Sprachverstehen im Störgeräusch bei SSD-Nutzern im Vergleich mit einer normalhörenden (NH) Gruppe zu untersuchen. Fünf erfahrene SSD-Nutzer (Ø Alter 50 Jahre) und 21 NH (Ø Alter 28 Jahre) nahmen an der Studie teil. Die Untersuchungen erfolgten in einem reflexionsarmen Raum unter Freifeldbedingungen und im Nachhall (Raumsimulation eines Hörsaals). Es wurde der mittlere Lokalisationsfehler für gepulste breitbandige Rauschstimuli in der Horizontalebene für Prüfwinkel zwischen ±60° frontal bestimmt. Die Sprachverständlichkeitsschwelle (SVS) im Störgeräusch wurde mit vier zeitlich dekorrelierten Störschallquellen (amplitudenmoduliertes Rauschen) bei frontaler Sprachwiedergabe ermittelt. Der mittlere Winkelfehler lag bei den SSD-Nutzern ohne Nachhall im Median bei 12,1° und in der NH-Gruppe bei 1,8°. Es zeigte sich eine große Streuung unter den SSD Nutzern. Die SSD-Nutzer erreichten im Freifeld eine mittlere SVS von ‑11,8 dB SNR und im Nachhall eine signifikant schlechtere SVS von -4,6 dB SNR (NH -14,0 dB SNR zu -10,3 dB SNR im Nachhall). Alle SSD-Nutzer zeigten eine für Alltagssituationen hinreichend genaue Lokalisationsleistung. Sowohl die Lokalisation von Schallen als auch das Sprachverstehen im Störgeräusch wird im Nachhall erschwert. Insbesondere im Sprachverstehen ist der Einfluss von Nachhall in der SSD-Gruppe ausgeprägter als in der NH-Gruppe.

Das Sprachverstehen in alltäglichen Situationen mit mehreren Störgeräuschquellen stellt eine besondere Schwierigkeit für Nutzer von Cochlea-Implantaten (CIs) dar. Das Ziel dieser Studie war die Untersuchung des Sprachverstehens von CI-Nutzern in dynamisch wechselnden Hörumgebungen mit komplexen Störgeräuschen und Nachhall. Zusätzlich wurde der Einfluss einer automatischen Szenenklassifikation (SCAN) auf das Sprachverstehen im Störgeräusch untersucht. Jeweils 16 uni- und bilateral versorgte CI-Nutzer (Cochlear Nucleus 6 Prozessoren) sowie 15 Normalhörende (NH) nahmen an der Studie teil. Die Sprachverständlichkeitsschwelle (SVS) im Störgeräusch wurde im Freifeld und im Nachhall bestimmt. Zur Prüfung des Klassifikators wurden die Testbedingungen in eine verschachtelte Variante des Oldenburger Satztests integriert. Die mittlere SVS über alle getesteten Konditionen betrug in der NH-Gruppe -10,7 dB SNR. In der unilateralen CI-Gruppe wurde ein Wert von 2,9 dB SNR (ohne Klassifikator) bzw. 1 dB SNR (mit Klassifikator) ermittelt. Bei der bilateralen CI-Gruppe zeigte sich eine SVS von 0 dB SNR und ‑1,5 dB SNR (jeweils ohne/mit Klassifikator). Beide CI-Gruppen zeigten die stärkste Verbesserung der SVS durch Einsatz des Klassifikators (Gewinn Unilateral: 4,2 dB; Bilateral: 4,1 dB) unter Freifeldbedingungen bei einer einzelnen Störquelle im hinteren Halbraum. Der Einsatz einer automatischen Situationserkennung kann das Sprachverstehen von CI-Nutzern in vielen Hörsituationen deutlich verbessern. Die Wirkung ist abhängig von Anzahl und Art der Störquellen sowie der Raumakustik.

Speech perception in everyday life with multiple noise sources is challenging for users of cochlea implants (CIs). The aim of this study was the evaluation of speech perception of CI users in dynamically changing listening situations with complex noises and reverberation. Additionally, the effect of automatic scene classification (SCAN) on speech perception was examined. 16 uni- and 16 bilateral CI users (Cochlear Nucleus 6 processors) as well as 15 normal hearing (NH) participated in this study. The speech reception threshold (SRT) in noise was determined under free field conditions and with reverberation. In order to test the effect of the classificator, the test conditions were integrated in an interleaved version of the Oldenburg Sentence Test (OLSA). The mean SRT across all conditions was -10.7 dB SNR in the NH group. The unilateral CI users achieved 2.9 dB SNR (without classificator) and 1 dB SNR (with classificator). The mean SRT of bilateral CI users was 0 dB SNR and -1.5 dB SNR (without and with classificator respectively). Both CI groups had their maximum improvement by applying the classificator in the free field condition with only one noise source in the rear hemisphere (Improvement unilateral: 4.2 dB; bilateral: 4.1 dB). Using the automatic scene classificator can improve speech perception of CI-Users in many listening situations. The effect depends on number and type of noise sources as well as the acoustic properties of the room.

In everyday life listening situations, communication is characterized by a variety of challenging acoustic scenes. Usually, background noise Anja Eichenauer Uwe Baumann sources are present and, additionally, direct sound in rooms is reflected Tobias Weißgerber from walls and surfaces. These reflections affect speech perception. However, audiological assessments are usually performed in rooms with low reverberation time. This work aims at implementing and eval1 Audiological Acoustics, Clinic for Otolaryngology, University uating a room simulation system to examine hearing ability in everyday life listening situations with different acoustic properties and reverberation. Hospital Frankfurt am Main, Germany With a room simulation software sound propagation was calculated in relation to the room geometry and acoustic room parameters. The direct sound and its reflections are presented according to their direction by using a multichannel playback system with 128 loudspeakers. Any desired room can be reconstructed in the laboratory under realistic and controllable acoustic conditions. The room simulation procedure was evaluated using an empty auditoriumwith different degrees of absorption properties. Technical measurements of reverberation time (RT) and distinctness (D50) showed good agreement with themodel data. Additionally, interaural level differences (ILDs) were recorded and correlated with speech reception thresholds. ILDs are reduced up to 10 dB with increasing reverberation. At the same time, spatial release frommasking (SRM) compared to free field conditions decreased up to 5.5 dB SNR. The determination of speech discrimination using the introduced room simulation system is a useful complement to established audiological measurements. The hearing performance under defined acoustic properties can be determined reproducibly and reliably.

Standard cochlea implant (CI) speech coding strategies transmit formant information only via the place of the stimulated electrode. In acoustic hearing, however, formant frequencies are additionally coded via the temporal rate of auditory nerve firing. This study presents a novel CI coding strategy ("Formant Locking (FL)-strategy") that varies stimulation rates in relation to extracted fundamental and formant frequencies. Simulated auditory nerve activity resulting from stimulation with the FL-strategy shows that the FL-strategy triggers spike rates that are related to the formant frequencies similar as in normal hearing, and greatly different than in a standard CI strategy. Vowel recognition in seven CI users via direct stimulation of their electrode array shows that the FL-strategy results in significantly increased scores of the vowels /u/ and /i/ compared to a standard CI strategy. However, at the same time, a decrease in scores for /o/ and /e/ occurred. A microscopic speech intelligibility model involving an automatic speech recognizer reveals good agreement between modeled and predicted confusion matrices for the FL-strategy. This suggests that microscopic models can be used to test CI strategies in the development phase, and gives indications which cues might be used by the listeners for speech recognition.

This study compares bone conduction (BC) thresholds obtained with two bone vibrators (BV): The Radioear B71 and an advanced BV, the Radioear B81. B81 has less distortion and is capable of higher output levels. Two tests with 20 normal hearing subjects were conducted to determine if the low distortion of B81 offers any advantages for audiometry. Hearing threshold differences between B71 and B81 are only significant at 250 Hz for levels between 20 dB hearing level (HL) and 30 dB HL. At other frequencies and higher levels, where B81 also performs with less distortion than B71, tactile responses interfere before B81 can be advantageous.