The Use of a Novel, Nonsurgical Bone Conduction Hearing Aid System for the Treatment of Conductive Hearing Loss.

OBJECTIVE: Conventional bone conduction hearing aid solutions often require a cumbersome retention system such as a headband or cap. This study aims to determine if a novel, nonsurgical bone conduction aid utilizing an adhesive attachment over the mastoid is equivalent to the conventional bone conduction hearing aid (BCHA) for the management of conductive hearing loss. STUDY DESIGN: Prospective, single-subject randomized, crossover trial. SETTING: Tertiary referral center. PATIENTS: Eleven adults and 1 child between 11 and 70 years of age with unilateral conductive hearing loss were enrolled. INTERVENTION: Patients had their baseline hearing assessed and were randomized to receive either the novel device or BCHA headband system. Hearing loss etiologies were varied and included cholesteatoma, otosclerosis, chronic otitis media, and previous head and neck surgery. Patients had their baseline hearing assessed and trialled both the novel device or the BCHA headband system. Patients were randomly assigned one device which was worn for 2 weeks followed by a 2-week trial with the alternate device. MAIN OUTCOME MEASURE: Pure-tone thresholds and speech discrimination in quiet and noise were tested and patients also completed the short form of the Speech Spatial and Quality of Hearing (SSQ) questionnaire. RESULTS: The mean unaided 4 frequency pure-tone average (PTA) air conduction threshold was 53.9 dB, bone conduction was 11.9 dB, and the mean air bone gap was 42 dB in the target ear. One patient with an adhesive skin reaction could not complete the protocol. Aided PTA and threshold testing between 250 Hz to 8000 Hz showed statistically equivalent results between both devices. The aided CNC word score, signal-to-noise ratio, and SSQ scores were also equivalent between both devices. CONCLUSION: The novel bone conduction aid demonstrates equivalent performance to the conventional BCHA headband solution. The novel device should be considered an alternative option where the cosmetic and comfort issues of a headband worn device are a concern.

High frequency rheometry of viscoelastic coatings with the quartz crystal microbalance.

We describe a quantitative method for using the quartz crystal microbalance (QCM) to characterize the high frequency viscoelastic response of glassy polymer coatings with thicknesses in the 5-10 µm regime. By measuring the frequency and dissipation at the fundamental resonant frequency (5 MHz) and at the third harmonic (15 MHz), we obtain three independent quantities. For coatings with a predominantly elastic response, characterized by relatively low phase angles, these quantities are the mass per unit area of the coating, the density-shear modulus product, and the phase angle itself. The approach was demonstrated with a model polyurethane coating, where the evolution of these properties as a function of cure time was investigated. For fully cured films, data obtained from the QCM are in good agreement with results obtained from traditional dynamic mechanical analysis.