Lars Holme Nielsen

Distortion product otoacoustic emissions. The influence of the middle ear transmission.

Distortion product otoacoustic emissions (DPOEs) were recorded in 8 normal hearing subjects (16 ears, mean age 37) in order to evaluate the sensitivity of the DPOE amplitudes as a function of pneumatic changes (-400 to +200 daPa) in the external ear canal. The responses were collected using time averaging and subsequent FFT-analysis of the collected data. Distortion products were measured at the following geometric mean frequencies: 1,000, 2,000, 4,000, 6,000 and 8,000 Hz. The results show that the amplitudes of the distortion products depend on an optimal transmission through the middle ear, and that measurements of DPOEs should always be preceded by determination of the middle ear pressure. The present findings are in good agreement with investigations based on evoked otoacoustic emissions published by other researchers.

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.

Clinical Significance of Relative Probe-Tone Levels on Distortion Product Otoacoustic Emissions

The effect of systematic variations in the relative levels (L1, L2) of two primary tones (f1, f2) on the amplitude of the distortion product otoacoustic emission (DPOAE) at 2f1-f2 and f1 < f2 was investigated in 14 ears from 7 normally hearing human subjects. The primary tones (f2:f1 = 1.23) were geometrically centred at the standard clinical frequencies of 0.5, 1, 1.5, 2, 3, 4, 6 and 8 kHz. The quantity L1-L2 was varied systematically from -10 dB through + 10 dB with L2 held constant at 75 dB SPL for negative values, L1 held constant at 75 dB SPL for positive values, and L1 = L2 = 75 dB SPL at 0 dB relative difference. The maximum amplitudes of the distortion products were generated when L1 = L2 at all geometric centre frequencies except 8 kHz. The reduction of the DPOAE with reduction of L1 was linear at a rate that gradually increased as a function of geometric mean frequency. To a lesser extent, the reduction of the DPOAE with reduction of L2 also was linear but at a rate that systematically decreased as a function of geometric mean frequency. The results suggest, that to maximize the level of the distortion product for clinical purposes, the relative levels of the primary tones should be equal to each other, at least when overall stimulus levels are around 75 dB SPL and f2:f1 = 1.23.

Clinical Significance of Probe-tone Frequency Ratio on Distortion Product Otoacoustic Emissions

Parametric variations in the ratio of primary-tone frequencies were explored to optimize the amplitude of the 2f1-f2 distortion product otoacoustic emission for clinical purposes. Ten ears from 5 normally hearing human subjects were examined with primary tones geometrically centred around the standard audiometric frequencies of 0.5, 1, 1.5, 2, 3, 4, 6 and 8 kHz. The distortion product at the frequency 2f1-f2 (f1 < f2) was measured at six probe tone frequency ratios (f2:f1) varying between 1.15 and 1.40 using equal level primaries of 75 dB SPL. The results showed that a single f2:f1 ratio between 1.20 and 1.25 provides a reasonable value for clinical use in that it optimizes the magnitude of the distortion product at 2f1-f2, provides for sufficient resolution in the test frequency range, and is applicable to the standard clinical test frequencies.

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.

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.

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.

Follow‐up of 5‐ to 11‐year‐old children treated for persistent pulmonary hypertension of the newborn

Aim: Determine the prevalence of sensorineural hearing loss (SNHL) and relate this to cumulative exposure to hypoxia, hypocapnia and hypotension. Describe chronic health problems among 5‐ to 11‐year‐old children treated for persistent pulmonary hypertension of the newborn (PPHN).

The Influence of Spontaneous Otoacoustic Emissions on the Amplitude of Transient-evoked Emissions

The aim of the study was to analyse whether the presence of spontaneous otoacoustic emissions (SOAEs) in a group of normal-hearing adults is related to larger transient evoked otoacoustic emission (TEOAE) amplitudes when compared to a similar adult population without SOAEs. Twenty-four normal-hearing subjects participated in the investigation. They were selected to form two groups of 12, one containing only subjects with measurable spontaneous emissions, the other of members who had no measurable spontaneous emissions. Each group comprised 7 males and 5 females. TEOAEs were recorded in both linear and non-linear mode, and equivalent sound pressure levels in different octave frequency bands were calculated. For each frequency band, the comparison of the equivalent sound pressure levels in the two selected groups showed statistically significant differences. Therefore, when normative TEOAE data were collected with the purpose of establishing a normative reference for the assessment of cochlear hearing loss, it is mandatory to search for and, when pertinent, to compensate for the presence of SOAEs.