William Hodgetts

What is the influence of background noise and exercise on the listening levels of iPod users

Abstract The widespread use of portable listening devices (PLDs) has increased concern about the potential for hearing impairment caused by their use. The current study investigated the effects of external noise and exercise on the use of PLDs. The 24 participants listened to the same song on an iPod during rest-in-quiet, rest-in-noise, and exercise-in-noise conditions. Preferred listening levels (PLLs) were recorded and participants’ maximum noise doses were calculated. Participants selected significantly higher listening levels in both noise conditions than in the quiet condition. The variability of volume selection was reduced significantly in the noise conditions. The maximum daily noise dose would have been exceeded by seven participants in the rest-in-noise condition and by eight in the exercise-in-noise condition compared to one participant in the rest-in-quiet condition. These results indicated that increased background noise causes individuals to increase the volume on their PLDs to potentially dangerous levels and that increased noise alone was not the only factor affecting the participants as the addition of exercise induced even further increases in PLLs. Sumario El amplio uso de instrumentos portátiles de escucha (PLDs) ha incrementado la preocupación sobre el potencial que tiene su uso como causa de discapacidad auditiva. En este estudio se investigaron los efectos del ruido externo y del ejercicio sobre el uso de iPods. Los 24 participantes escucharon en un iPod la misma canción, en condiciones de descanso-en-silencio, descanso-con-ruido y ejercicio-en condiciones ruidosas. Se registraron los niveles de escucha preferidos (PLLs) y se calcularon las dosis máximas de ruido en los participantes. Estos seleccionaron niveles de escucha significativamente mayores en las dos condiciones con ruido pero no en la de silencio. La dosis diaria máxima de sonido se excedió en siete participantes, en la condición de descanso-en-silencio y por ocho en la de ejercicio-con ruido, comparada con 1 en la condición de descanso- en-silencio. Estos resultados indican que el aumento del ruido de fondo hace que los individuos incrementen el volumen de sus iPods hasta niveles potencialmente peligrosos y que el incremento de ruido en forma aislada no es el único factor que afecta a los participantes, como lo es la adición de ejercicio que incluso induce incrementos adicionales en los PLLs.

Effects of applied contact force and volume control setting on output force levels of the BAHA® Softband

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.

A comparison of three approaches to verifying aided Baha output.

Abstract Objective: The objective of the present study was to compare three methods of estimating the audibility of aided speech using the Baha. Subjects: 23 Adult Baha users with primarily bilateral conductive hearing loss were recruited from the Bone Conduction Amplification Program at the Institute for Reconstructive Sciences in Medicine in Edmonton, Alberta, Canada. Methods: A test Baha was set to each subjects preferred listening level. The same Baha was used to assess the audibility of the long-term average speech spectrum (LTASS) for each of the following three approaches: 1) Aided soundfield thresholds, 2) Real Ear SPL, and 3) Real Head Acceleration Level. Results: Significant differences were discovered between the three approaches. Aided soundfield thresholds consistently over-estimated the sensation level of aided speech. The Real Ear SPL approach provided reasonable estimates in the mid-frequencies. However, low- and high-frequency estimates for the Real Ear approach have significant limitations. Conclusions: The Real Head Acceleration Level appears to be the most accurate method of determining aided audibility with the Baha. Sumario El objetivo del presente estudio fue comparar tres métodos de estimación del nivel de sensación (audibilidad del LTASS) del lenguaje amplificado usando el Baha. Se reclutaron 23 usuarios adultos del Baha, primariamente con hipoacusia conductiva bilateral, del Programa de Amplificación por Conducción Ósea del Instituto de Ciencias Reconstructivas en Medicina en Edmonton, Alberta, Canadá. Un Baha de prueba fue colocado al nivel preferido de escucha de cada sujeto. El mismo Baha fue utilizado para evaluar la audibilidad del espectro promediado a largo plazo de lenguaje (LTASS) para cada uno de los siguientes tres enfoques: 1) Umbrales amplificados en campo sonoro, SPL en Oído-Real, y el Nivel Real de Aceleración de la Cabeza. Se descubrieron diferencias significativas entre los tres enfoques. Los umbrales amplificados en campo sonoro sobre-estimaron consistentemente el nivel de sensación del lenguaje amplificado. El enfoque de SPL en Oído-Real proporcionó estimados razonables en las frecuencias medias. Sin embargo, los estimados para frecuencias bajas y altas para el enfoque de Oído-Real tuvieron limitaciones significativas. El Nivel Real de Aceleración de la Cabeza parece ser el método más exacto para determinar la audibilidad amplificada del Baha.

Technology-limited and patient-derived versus audibility-derived fittings in bone-anchored hearing aid users: a validation study.

Objectives: Current approaches to fit bone-anchored hearing aid (Baha) rely heavily on patient feedback of “loudness” and “sound quality.” Audiologists are limited to this approach for two reasons: (1) the technology in current models of Baha does not allow for much fine-tuning of frequency response or maximum output on an individual basis and (2) there has not been a valid approach to verify the frequency response or maximum output on an individual basis. The objectives of this study are to (1) describe an alternative approach to fit Baha, an “audibility-derived (AD)” fitting, and (2) test whether outcomes improve with this new fitting compared with the current “patient-derived (PD)” fitting. Design: This study used a repeated measures design where each subject experienced both the AD and PD fittings in random order. Subjects were tested on a variety of outcome measures including output levels of aided speech, hearing in noise test (quiet and in noise), consonant recognition in noise, aided loudness, and subjective percentage of words understood. Results: Electromechanical testing revealed significantly higher aided output with the AD fitting, especially in the high frequencies. Subjects performed significantly better in all outcome measures with the AD fitting approach except when testing aided loudness and subjective perception for which the differences were nonsignificant. When the input levels to the Baha were soft, advantages for the AD fitting were emerging on these tests, but they did not reach significance. Conclusions: This study presents a more objective, fitting approach for Baha that leads to better outcomes in the laboratory. The next steps will be to test these fittings in the real world and to make the approach generally available to clinicians fitting Bahas.

Advanced System for Implant Stability Testing (ASIST)

This study presents the Advanced System for Implant Stability Testing (ASIST) which provides a non-invasive, quantitative measure of the stability of percutaneous implants used for craniofacial rehabilitation such as bone anchored hearing aids or dental implants. The ASIST uses an impact technique coupled with an analytical model which allows the measure to be independent of the system components. This paper presents a laboratory evaluation of the ASIST for the Oticon Medical Ponto and the Cochlear Baha Connect bone anchored hearing aid (BAHA) systems. There is minimal effect of abutment length on the ASIST Stability Coefficient (ASC) value, indicating that the method is able to isolate the interface properties from the overall system and the measurement is independent of attached components. Additionally, the ASIST was able to detect differences between different implant installations suggesting that it may be sensitive to changes in interface stiffness.

Flow and Grit by Design: Exploring Gamification in Facilitating Adherence to Swallowing Therapy

Purpose Delivery of swallowing therapy is faced with challenges regarding access to in-clinic services and adherence to prescribed home programs. Mobile health (mHealth) technologies are being developed at a rapid pace to address these difficulties. Whereas some benefits to using these modern tools for therapy are obvious (e.g., electronic reminders), other advantages are not as well understood. One example is the potential for mHealth devices and apps to enhance adherence to treatment regimens. Method This article introduces a number of psychological concepts that relate to adherence and that can be leveraged by mHealth. Elements that contribute to flow (optimal experience) during an activity and those that reinforce grit (perseverance to achieve a long-term goal) can be used to engage patients in their own rehabilitation. Results The experience of flow can be targeted by presenting the rehabilitation exercise as an optimally challenging game, one that offers a match between challenge and ability. Grit can be supported by reinforcing routine and by varying the therapy experience using different games. Conclusions A combination of hardware and software design approaches have the potential to transform uninteresting and repetitive activities, such as those that make up swallowing therapy regimens, into engaging ones. The field of gamification, however, is still developing, and gamified mHealth apps will need to withstand scientific testing of their claims and demonstrate effectiveness in all phases of outcome research.

Maturation of Mechanical Impedance of the Skin-Covered Skull: Implications for Soft Band Bone-Anchored Hearing Systems Fitted in Infants and Young Children.

Objectives: Little is known about the maturational changes in the mechanical properties of the skull and how they might contribute to infant–adult differences in bone conduction hearing sensitivity. The objective of this study was to investigate the mechanical impedance of the skin-covered skull for different skull positions and contact forces for groups of infants, young children, and adults. These findings provide a better understanding of how changes in mechanical impedance might contribute to developmental changes in bone conduction hearing, and might provide insight into how fitting and output verification protocols for bone-anchored hearing systems (BAHS) could be adapted for infants and young children. Design: Seventy-seven individuals participated in the study, including 63 infants and children (ages 1 month to 7 years) and 11 adults. Mechanical impedance magnitude for the forehead and temporal bone was collected for contact forces of 2, 4, and 5.4 N using an impedance head, a BAHS transducer, and a specially designed holding device. Mechanical impedance magnitude was determined across frequency using a stepped sine sweep from 100 to 10,000 Hz, and divided into low- and high-frequency sets for analysis. Results: Mechanical impedance magnitude was lowest for the youngest infants and increased throughout maturation in the low frequencies. For high frequencies, the youngest infants had the highest impedance, but only for a temporal bone placement. Impedance increased with increasing contact force for low frequencies for each age group and for both skull positions. The effect of placement was significant for high frequencies for each contact force and for each age group, except for the youngest infants. Conclusions: Our findings show that mechanical impedance properties change systematically up to 7 years old. The significant age-related differences in mechanical impedance suggest that infant–adult differences in bone conduction thresholds may be related, at least in part, to properties of the immature skull and overlying skin and tissues. These results have important implications for fitting the soft band BAHS on infants and young children. For example, verification of output force form a BAHS on a coupler designed with adult values may not be appropriate for infants. This may also hold true for transducer calibration when assessing bone conduction hearing thresholds in infants for different skull locations. The results have two additional clinical implications for fitting soft band BAHSs. First, parents should be counseled to maintain sufficient and consistent tightness so that the output from the BAHS does not change as the child moves around during everyday activities. Second, placement of a BAHS on the forehead versus the temporal bone results in changes in mechanical impedance which may contribute to a decrease in signal level at the cochlea as it has been previously demonstrated that bone conduction thresholds are poorer at the forehead compared with a temporal placement.

“To Name or Not to Name: That is the Question”: The Role of Response Inhibition in Reading

Reading is a complex process that includes the integration of information about letters (graphemes) and sounds (phonemes). In many circumstances, such as noisy environments, response inhibition is an additional factor that plays a marked role in successful oral reading. Response inhibition can take the form of task relevant inhibition (i.e., foils in a go/no-go task) and task irrelevant inhibition (i.e., distractor information). Here we investigated task relevant inhibition by having participants (N = 30) take part in two tasks: go/no-go naming with nonwords foils (GNG-NW) and go/no-go naming with pseudohomophones foils (GNG-PH). Also, we investigated the addition of task irrelevant inhibition by having participants (N = 28) take part in two tasks: GNG-NW + information masking and GNG-PH + information masking. We provide evidence that during a task relevant inhibition task, sub-word sound level information can be successfully inhibited, as evidenced by comparable response times for regular words and exception words, provided the foils do not contain familiar sound-based information (GNG-NW). In contrast, regular words were read aloud faster than exception words in a GNG-PH task, indicating that sub-word level interference occurs when the foils contain familiar sound-based information. The addition of task irrelevant inhibition (i.e., information masking at the phoneme level), served to increase response time overall, but did not impact the pattern of response times between regular words and exception words. Together these findings provide useful information regarding the role of response inhibition in word recognition and may be useful in computational models of word recognition and future work may benefit from accounting for the effects outlined in this paper.

Comparison of implant stability measurement devices for bone-anchored hearing aid systems

Statement of problem. The success of implants for bone‐anchored hearing aids (BAHA) relies on proper osseointegration at the bone‐implant interface. Clinical evaluation of implant stability is important in prescribing loading, identifying the risk of failure, and monitoring the long‐term health of the implant. Purpose. The purpose of this in vitro study was to evaluate 2 measurement systems for BAHA implant stability: the most commonly used, Osstell implant stability quotient (ISQ), and a newly developed advance system for implant stability testing (ASIST). Material and methods. BAHA implants (Oticon Medical Ponto and Cochlear BAHA Connect systems) were installed in plastic materials with adhesive to simulate implants integrated in bone with varying levels of interface stiffness. Different lengths of BAHA abutments were used with each implant specimen, and stability measurements were obtained with both the Osstell ISQ and the ASIST systems. The measurement systems were evaluated in terms of sensitivity to differences in interface stiffness and the effect of abutment length on the stability measurement. Repeated measures ANOVA followed by post hoc t tests were used for the comparisons with a Bonferroni adjusted alpha value of .05/15 = .003 to control for potential type 1 errors. Results. Changing the abutment length of a single implant installation had minimal effect on the ASIST stability coefficient, whereas large variations were observed in the Osstell implant stability quotient (ISQ). The Osstell showed a clear relationship of decreasing ISQ with increasing abutment length for both the Oticon Medical and the Cochlear implant systems. Both the ASIST and the Osstell were found to be sensitive to changes in interface properties, with the ASIST being more sensitive to these changes. Conclusions. The ASIST system is more sensitive to changes in interface properties and shows smaller variation because of changes in abutment length than the Osstell ISQ system.

Application of the advanced system for implant stability testing (ASIST) to natural teeth for noninvasive evaluation of the tooth root interface

In this paper we present the development of the Advanced System for Implant Stability Testing (ASIST) for application to natural teeth. The ASIST uses an impact measurement combined with an analytical model of the system and surrounding support to provide a measure of the interface stiffness. In this study, an analytical model is developed for a single-rooted natural tooth allowing the ASIST to estimate the stiffness characteristics of the periodontal ligament (PDL). The geometry and inertia parameters of the tooth model are presented in two ways: (1) using full CT scans of the individual tooth and (2) using an approximate geometry model with estimates of only the tooth length and diameter. The developed system is evaluated with clinical data for patients undergoing orthodontic treatment. This study shows that ASIST technique can be applied to natural teeth to estimate the stiffness characteristics of the PDL. The developed system can provide a valuable clinical tool for assessment of tooth stability properties and PDL stiffness in a variety of clinical situations such as dental trauma, orthodontics, and periodontology.