Earpieces and methods of forming earpieces for radio frequency (RF) mitigation are provided. An earpiece is configured to be inserted in an ear canal. The earpiece includes an insertion element and a sealing section disposed on the insertion element and configured to conform to the ear canal. The sealing section is configured to substantially mitigate radio frequency (RF) transmission and to substantially isolate the ear canal from an ambient environment.

At least one exemplary embodiment is directed to a method of providing RF mitigation exposure to a user.

In one aspect, an orthodontic appliance can include a shell having a plurality of cavities shaped to receive a patient's teeth. The shell can include an exterior layer and an interior layer having a stiffness less than a stiffness of the exterior layer. A discontinuity can be formed in the exterior layer.

A damped propshaft assembly with a hollow shaft and a tuned damper, which is received in the hollow shaft and includes a liner and a damping member. The liner's mass and stiffness are tuned to attenuate one or more of a bending mode vibration and a torsion mode vibration that occurs at a first predetermined frequency. The liner is not configured to substantially damp shell mode vibration that occurs at a frequency that is not equal to the first predetermined frequency. The damping member is coupled to the liner and is configured to primarily attenuate shell mode vibration in the hollow shaft at one or more desired frequencies. The tuned damper attenuates the at least one of the bending moment vibration and the torsion mode vibration at the first predetermined frequency and also attenuates shell mode vibration. A method for forming a damped propshaft assembly is also provided.

Earpieces and methods of forming earpieces for radio frequency (RF) mitigation are provided. An earpiece is configured to be inserted in an ear canal. The earpiece includes an insertion element and a sealing section disposed on the insertion element and configured to conform to the ear canal. The sealing section is configured to substantially mitigate radio frequency (RF) transmission and to substantially isolate the ear canal from an ambient environment.

Earpieces and methods of forming earpieces for radio frequency (RF) mitigation are provided. An earpiece is configured to be inserted in an ear canal. The earpiece includes an insertion element and a sealing section disposed on the insertion element and configured to conform to the ear canal. The sealing section is configured to substantially mitigate radio frequency (RF) transmission and to substantially isolate the ear canal from an ambient environment.

Earpieces and methods of forming earpieces for radio frequency (RF) mitigation are provided. An earpiece is configured to be inserted in an ear canal. The earpiece includes an insertion element and a sealing section disposed on the insertion element and configured to conform to the ear canal. The sealing section is configured to substantially mitigate radio frequency (RF) transmission and to substantially isolate the ear canal from an ambient environment.

Earpieces and methods of forming earpieces for radio frequency (RF) mitigation are provided. An earpiece is configured to be inserted in an ear canal. The earpiece includes an insertion element and a sealing section disposed on the insertion element and configured to conform to the ear canal. The sealing section is configured to substantially mitigate radio frequency (RF) transmission and to substantially isolate the ear canal from an ambient environment.

Earpieces and methods of forming earpieces for radio frequency (RF) mitigation are provided. An earpiece is configured to be inserted in an ear canal. The earpiece includes an insertion element and a sealing section disposed on the insertion element and configured to conform to the ear canal. The sealing section is configured to substantially mitigate radio frequency (RF) transmission and to substantially isolate the ear canal from an ambient environment.

A damped propshaft assembly with a hollow shaft and a tuned damper, which is received in the hollow shaft and includes a liner and a damping member. The liner's mass and stiffness are tuned to attenuate one or more of a bending mode vibration and a torsion mode vibration that occurs at a first predetermined frequency. The liner is not configured to substantially damp shell mode vibration that occurs at a frequency that is not equal to the first predetermined frequency. The damping member is coupled to the liner and is configured to primarily attenuate shell mode vibration in the hollow shaft at one or more desired frequencies. The tuned damper attenuates the at least one of the bending moment vibration and the torsion mode vibration at the first predetermined frequency and also attenuates shell mode vibration. A method for forming a damped propshaft assembly is also provided.