Steen Østergaard Olsen

The Relationship Between the Uncomfortable Loudness Level and the Acoustic Reflex Threshold for Pure Tones in Normally-hearing and Impaired Listeners—A Meta-analysis

The objective of this study was to determine the potential of the acoustic reflex threshold (ART) as a predictor of the uncomfortable level (ULL) and to identify related areas for investigations in the future. Eleven studies reporting data from 141 normally-hearing and 240 impaired hearing subjects have been reviewed, focusing on methods, test conditions and subjects. Results and conclusions are discussed and new calculations have been performed on the reported data. The median difference between ART and ULL across studies and frequencies was 5 dB both in normally-hearing and impaired subjects. Some authors argue, that although a close relationship of mean values of the two measurements may exist, prediction of the ULL based on ART measurement will be inaccurate because of high inter-subject variability. A statistically significant correlation exists between the mean HTL, the mean ART and the mean ULL in impaired hearing, while a relationship between the mean ART and the mean ULL does not exist in normal hearing. Based on pooled data across frequencies from the reviewed studies the mean ULL= (0.64 x mean ART+38) dB HL. The discrepancies between the results found in the reviewed studies may be explained by different instructions and stimulus presentation orders when assessing the ULL, difficulty in assessing the sound pressure level in the ear canal, influence of varying background noise levels and different admission criteria. It is recommended that the relationship between different loudness levels and the ART be investigated in normally-hearing subjects and in subjects with different levels of impairment, using standardized instructions. To further provide uniformity of the test material groups should be selected according to history of middle ear diseases and the use of hearing aids.

Acceptable noise level with Danish, Swedish, and non-semantic speech materials.

Abstract Objective: Acceptable noise level (ANL) has been established as a method to quantify the acceptance of background noise while listening to speech presented at the most comfortable level. The aim of the present study was to generate Danish, Swedish, and a non-semantic version of the ANL test and investigate normal-hearing Danish and Swedish subjects’ performance on these tests. Design: ANL was measured using Danish and Swedish running speech with two different noises: Speech-weighted amplitude-modulated noise, and multitalker speech babble. ANL was also measured using the non-semantic international speech test signal (ISTS) as speech signal together with the speech-weighted amplitude-modulated noise. The latter condition was identical in both populations. Study sample: Forty Danish and 40 Swedish normal-hearing subjects. Results: In both populations ANL results were similar to previously reported results from American studies. Generally, significant differences were seen between test conditions using different types of noise within ears in each population. Significant differences were seen for ANL across populations, also when the non-semantic ISTS was used as speech signal. Conclusions: The present findings indicate that there are extrinsic factors, such as instructions, affecting the ANL results.

Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

Abstract Objective: The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users’ ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association between ANL and outcome of the international outcome inventory for hearing aids (IOI-HA). Design: ANL was measured in three conditions in both ears at two test sessions. Subjects completed the IOI-HA and the ANL questionnaire. Study sample: Sixty-three Danish hearing-aid users; fifty-seven subjects were full time users and 6 were part time/non users of hearing aids according to the ANL questionnaire. Results: ANLs were similar to results with American English speech material. The coefficient of repeatability (CR) was 6.5–8.8 dB. IOI-HA scores were not associated to ANL. Conclusions: Danish and non-semantic ANL versions yield results similar to the American English version. The magnitude of the CR indicates that ANL with Danish and non-semantic speech materials is not suitable for prediction of individual patterns of future hearing-aid use or evaluation of individual benefit from hearing-aid features. The ANL with Danish and non-semantic speech materials is not related to IOI-HA outcome.

Does the acceptable noise level (ANL) predict hearing-aid use?

Abstract Objective: It has been suggested that individuals have an inherent acceptance of noise in the presence of speech, and that different acceptance of noise results in different hearing-aid (HA) use. The acceptable noise level (ANL) has been proposed for measurement of this property. It has been claimed that the ANL magnitude can predict hearing-aid use patterns. Many papers have been published reporting on different aspects of ANL, but none have challenged the predictive power of ANL. The purpose of this study was to discuss whether ANL can predict HA use and how more reliable ANL results can be obtained. Design: Relevant literature regarding the ANL was found on Medline, Embase, and Google Scholar. Additional information was found as references in the included papers and through personal contacts, for instance when attending audiology conferences. Study sample: Forty-five papers published in peer reviewed journals as well as a number of papers from trade journals, posters and oral presentations from audiology conventions. Conclusions: An inherent acceptance of noise in the presence of speech may exist, but no method for precise measurement of ANL is available. The ANL model for prediction of HA use has yet to be proven valid.

Real-ear measurement verification for open, non-occluding hearing instruments

Real-ear measurements using the modified pressure method with concurrent (real-time) equalization can be inaccurate, when amplified sound leaks out of the ear canal and reaches the reference microphone. In such situations the reference microphone will detect an increased sound level and reduce the output of the loudspeaker to maintain the desired level. The risk of having errors due to leaks increases if digital feedback suppression (DFS) is used, thus achieving higher feedback-free gain levels. The following hypotheses were tested: a) using the concurrent equalization method for fitting hearing instruments with DFS may result in underestimated real-ear insertion gain (especially when using open fittings) and b) as the benefit of the DFS system increases, this error also increases. Real-ear measurements were carried out in twenty-one subjects using the modified pressure method with stored equalization as well as with concurrent equalization. The results of the study supports both hypotheses. As a consequence it is recommended to use a stored equalization method for real-ear measurements of hearing instruments with DFS and open fitting.

Acceptable noise level: Repeatability with Danish and non-semantic speech materials for adults with normal hearing

Objective: The acceptable noise level (ANL) is used to quantify the amount of background noise that subjects can accept while listening to speech, and is suggested for prediction of individual hearing-aid use. The aim of this study was to assess the repeatability of the ANL measured in normal-hearing subjects using running Danish and non-semantic speech materials as stimuli and modulated speech-spectrum and multi-talker babble noises as competing stimuli. Design: ANL was measured in both ears at two test sessions separated by a period ranging from 12 to 77 days. At each session the measurements at the first and the second ear were separated in time by 15–30 minutes. Bland-Altman plots and calculation of the coefficient of repeatability (CR) were used to estimate the repeatability. Study sample: Thirty nine normal-hearing subjects. Results: The ANL CR was 6.0–8.9 dB for repeated tests separated by about 15–30 minutes and 7.2–10.2 dB for repeated tests separated by 12 days or more. Conclusions: The ANL test has poor repeatability when assessed with Danish and non-semantic speech materials on normal-hearing subjects. The same CR among hearing-impaired subjects would imply too poor repeatability to predict individual patterns of future hearing-aid use.

Learning effect when using the Danish Hagerman sentences (Dantale II) to determine speech reception threshold.

The objective of the present study was to examine the learning effect found when using the Danish sentence test, Dantale II, in our daily clinical work. Specifically, the aim was to determine the within-visit and the inter-visit learning effects when the Dantale II is presented to aided hearing-impaired listeners who have not previously completed the task. Nineteen subjects participated in the study. The within-visit learning effect after listening to 160 sentences was found to be 3.2 dB, and the inter-visit learning effect was 1.6 dB with an inter-visit period range of 14–43 days. For research evaluation of algorithms or hearing aid settings, where the differences are expected to be small, it is recommended that a pool of test subjects are regularly tested using the Dantale II speech material. Moreover, a limitation of the number of signal processing test conditions is suggested.

The acceptable noise level: the effect of repeated measurements.

Abstract Objective: This study explores if increasing number of repetitions might improve the precision of the acceptable noise level (ANL) test. Design: We measured twelve ANL repetitions, i.e. four complete ANL tests (4 × 3 repetitions), at one session using diotic presentation and a non-semantic ANL version. Study sample: Thirty-two normal-hearing adults. Results: Small order and fatigue effects were seen. We used the coefficient of repeatability (CR) to assess the repeatability; CRs ranged between 3.9 and 7.6 dB for the four ANL tests. Using the twelve ANL repetitions we removed the variability of the ANL across subjects by normalizing the data to the individual mean ANL for the twelve repetitions. The mean normalized ANL across the subjects rapidly approached the ANL normalized to the individual mean for the 12 repetitions (0 dB), and after three repetitions the SD seemed to be stable at about 3 dB. Conclusions: The findings suggest that both order and fatigue affect the ANL. The findings also suggest that it may be more accurate to speak of an acceptable noise range than ANL. These findings have large implications for how we understand acceptable noise and it would explain a large part of the variability seen among normal-hearing and perhaps hearing-impaired subjects.

Evaluation of long-term patient satisfaction and experience with the Baha® bone conduction implant

Abstract Objective: Evaluate long-term patient satisfaction with bone-anchored hearing aids (the BahaR, now referred to by Cochlear as a ‘bone conduction implant’) in our hospital clinic spanning the eighteen-year period from the inception of our Baha program. The researchers further wished to analyse the various factors leading to patient satisfaction/dissatisfaction with their Baha. We developed a new questionnaire to obtain a comprehensive impression of individual patient practices, general satisfaction, and experiences with their Baha in respect to time spent using Baha, sound quality, annoyance from noise disturbance, ease of communication, cosmetic appearance, and satisfaction with the Baha amongst patient relatives, an aspect not previously investigated. Design: The study design was retrospective and executed as a postal questionnaire. The questionnaire was developed by the authors of this paper. Study sample: Patients operated on for a Baha at our hospital from 1989 to 2007. Results: The response rate was 92.4%. Eighty-six percent were satisfied or very satisfied with their Baha. Ninety-one percent of respondents could communicate using their Baha in a one-on-one conversational setting. A primary factor leading to dissatisfaction, experienced by 70% of responding patients, was annoyance from wind noise. Conclusions: Baha was found to yield good overall patient satisfaction over the long-term, and it was possible to identify specific factors attributing to satisfaction/dissatisfaction.

Comparison of two bone anchored hearing instruments: BP100 and Ponto Pro

Abstract Objective: This study aimed at investigating if there were differences in auditory performance, operation, or user preference between the Ponto Pro or the BP100, two bone anchored hearing instruments (BAHI) with modern sound processing technology. Design: Subjects wore the devices in daily life in a crossover study for periods ranging from 25 to 63 days. A speech-in-noise test was carried out as well as measures of noise reduction and feedback suppression algorithms. User satisfaction was reported using the NSH and the GHABP questionnaires. At the end of the test, subjects selected one of the devices for permanent use. Study sample: Twelve first-time users of BAHIs. Results: Eight subjects selected the Ponto Pro; four selected the BP100. The Ponto Pro was rated as easier to operate than the BP100, the visual appearance of the Ponto Pro was rated as nicer than that of the BP100, and speech understanding was rated higher with the Ponto Pro than with the BP100. Speech-in-noise tests showed improvements using directional microphones with the Ponto Pro. Conclusions: 67% of the subjects opted for permanent use of the Ponto Pro, which, compared to the BP100, was rated to have a nicer look, to be easier to operate, and to yield better speech intelligibility. Sumario Objetivo: Se propuso este estudio para investigar si existen diferencias en el rendimiento auditivo, la operación o la preferencia del usuario, entre los instrumentos auditivos osteo-integrados (BAHI) Ponto Pro y el BP100, con tecnología moderna de procesamiento de sonidos. Diseño: Los sujetos usaron estos instrumentos en la vida diaria en un estudio cruzado, por períodos que fueron de 25 a 63 días. Se llevó a cabo una prueba de lenguaje-en-ruido y también se midieron la reducción de ruido y los algoritmos de supresión de la retroalimentación. Se reportó la satisfacción del usuario usando los cuestionarios NSH y el GHABP. Al final de la prueba, los sujetos seleccionaron uno de los dos instrumentos para uso permanente. Muestra de estudio: Doce usuarios por primera vez, de BAHI. Resultados: Ocho sujetos seleccionaron el Ponto Pro y cuatro, el BP100. El Ponto Pro se consideró como más fácil de operar que el BP100; la apariencia visual del Ponto Pro, como mejor que la del BP100 y la comprensión del lenguaje como mayor con el Ponto Pro que con el BP100. Las pruebas de lenguaje-en-ruido mostraron mejoría con el uso de micrófonos direccionales del Ponto Pro. Conclusiones: 67% de los sujetos optaron por el uso permanente del Ponto Pro el cual, comparado con el BP100 se clasificó como de mejor apariencia, más fácil de operar y que proporciona mejor inteligibilidad del lenguaje.