The main objective of this study was to determine the influence of listening environment and earphone style on the preferred-listening levels (PLLs) measured in users' ear canals with a commercially-available MP3 player. It was hypothesized that listeners would prefer higher levels with earbud headphones as opposed to over-the-ear headphones, and that the effects would depend on the environment in which the user was listening. A secondary objective was to use the measured PLLs to determine the permissible listening duration to reach 100% daily noise dose. There were two independent variables in this study. The first, headphone style, had three levels: earbud, over-the-ear, and over-the-ear with noise reduction (the same headphones with a noise reduction circuit). The second, environment, also had 3 levels: quiet, street noise and multi-talker babble. The dependent variable was ear canal A-weighted sound pressure level. A 3 × 3 within-subjects repeated-measures ANOVA was used to analyze the data. Thirty-eight normal hearing adults were recruited from the Faculty of Rehabilitation Medicine at the University of Alberta. Each subject listened to the same song and adjusted the level until it “sounded best” to them in each of the 9 conditions. Significant main effects were found for both the headphone style and environment factors. On average, listeners had higher preferred listening levels with the earbud headphones, than with the over-the-ear headphones. When the noise reduction circuit was used with the over-the-ear headphones, the average PLL was even lower. On average, listeners had higher PLLs in street noise than in multi-talker babble and both of these were higher than the PLL for the quiet condition. The interaction between headphone style and environment was also significant. Details of individual contrasts are explored. Overall, PLLs were quite conservative, which would theoretically allow for extended permissible listening durations. Finally, we investigated the maximum output level of the MP3 player in the ear canals of authors 1 and 3 of this paper. Levels were highest with the earbud style, followed by the over-the-ear with noise reduction. The over-the-ear headphone without noise reduction had the lowest maximum output. The majority of MP3 players are sold with the earbud style of headphones. Preferred listening levels are higher with this style of headphone compared to the over-the-ear style. Moreover, as the noise level in the environment increases, earbud users are even more susceptible to background noise and consequently increase the level of the music to overcome this. The result is an increased sound pressure level at the eardrum. However, the levels chosen by our subjects suggest that MP3 listening levels may not be as significant a concern as has been reported recently in the mainstream media.

We examined the ability of 40 young children (aged five to eight) to understand speech (monosyllables, spondees, trochees, and trisyllables) when listening in a background of real-life classroom noise. All children had some difficulty understanding speech when the noise was at levels found in many classrooms (i.e., 65 dBA). However, at an intermediate (-6 dB SNR) level, kindergarten and grade 1 children had much more difficulty than did older children. All children performed well in quiet, with results being comparable to or slightly better than those reported in previous studies, suggesting that the task was age appropriate and well understood. These results suggest that the youngest children in the school system, whose classrooms also tend to be among he noisiest, are the most susceptible to the effects of noise. Evaluamos la capacidad de 40 niños (edades de cinco a ocho) para entender el lenguaje (monosilábicos, espondaicos, trocaicos y trisilábicos) al escucharlo en medio de un auténtico ruido de fondo de aula de clase. Todos los niños tuvieron alguna dificultad para entender el lenguaje cuando el ruido estuvo a los niveles hallados en muchas aulas de clase (p.e., 65 dBA). Sin embargo, a un nivel intermedio (-6 dBA), los niños de jardín de infantes y de primer grado tuvieron más dificultad que los niños mayores. Todos los niños funcionaron bien en silencio, con resultados comparables o hasta ligeramente superiores a los reportados en estudios previos, sugiriendo que la tarea era bien entendida y apropiada para la edad. Estos resultados sugieren que los niños más jóvenes dentro del sistema escolar, cuyas aulas de clase suelen ser las más ruidosas, son los más susceptibles a los efectos del ruido.

Objective: To develop an algorithm that prescribes targets for bone conduction frequency response shape, compression, and output limiting, along with a clinical method that ensures accurate transforms between assessment and verification stages of the clinical workflow. Design: Technical report of target generation and validation. Study sample: We recruited 39 adult users of unilateral percutaneous bone conduction hearing aids with a range of unilateral, bilateral, mixed and conductive hearing losses across the sample. Results: The initial algorithm over-prescribed output compared to the user’s own settings in the low frequencies, but provided a good match to user settings in the high frequencies. Corrections to the targets were derived and implemented as a low-frequency cut aimed at improving acceptance of the wearer’s own voice during device use. Conclusions: The DSL-BCD prescriptive algorithm is compatible with verification of devices and fine-tuning to target for percutaneous bone conduction hearing devices that can be coupled to a skull simulator. Further study is needed to investigate the appropriateness of this prescriptive algorithm for other input levels, and for other clinical populations including those with single-sided deafness, bilateral devices, children and users of transcutaneous bone conduction hearing aids.

The BAHA® Softband has been developed to provide a transcutaneous anchor for a BAHA® until a child is a surgical candidate for the percutaneous BAHA® implant. We tested the objective output force level of the BAHA® Classic 300 and Compact connected to a Softband on an artificial mastoid to determine: (1) the effects of direct contact force on output force levels (dB); and (2) the required volume control setting to ensure audibility of speech (assuming an average adult reference equivalent threshold force level). Direct contact force was varied from 2 to 5 N in 1 N steps. Output force level increased with increasing contact force. However, the average increase was 3 dB or lower, suggesting that the contact force is of minor importance. Volume control setting appears to be of much greater importance. It is suggested that the volume setting of either device be set to at least 2.5 to ensure audibility of conversational speech. Data from normal-hearing adults with simulated conductive hearing losses are presented to validate this conclusion.

Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet

Rehabilitation options for conductive and mixed hearing loss are continually expanding, but without standard outcome measures comparison between different treatments is difficult. To meaningfully i...