Abstract: A wearable device configured to be modeled as both a part of the source and a part of the load in an electro-acoustical source-and-load model of a system where a sound source is coupled to the ear canal. Such a wearable device may be used to determine the acoustic energy density at a point of measurement in or near the ear of a user.

Abstract: A method for operating an electro-acoustic system (11) arranges an electro-acoustic device (10), for occluding an ear canal on an ear and uses a signal processing device (16) for processing a signal incoming at the device (10). A correction unit (17) of the signal processing device (16) modifies the signal incoming at the device (10). To reduce, to avoid or to compensate for an interfering or undesired change in a perception of ambient noises during the use of an electro-acoustic device occluding the ear canal, with the correction unit (17), a signal outgoing from the device (10) is generated in order to achieve acoustic transparency, in which, on the basis of the outgoing signal, a received signal is generated at the eardrum which is adapted so as to correspond to a free-ear received signal at the eardrum in the case of a free ear canal without the device (10).

Abstract: A wearable device configured to be modeled as both a part of the source and a part of the load in an electro-acoustical sourceand-load model of a system where a sound source is coupled to the ear canal. Such a wearable device may be used to determine the acoustic energy density at a point of measurement in or near the ear of a user.

Abstract: A gun barrel that consists of a frame tube that encloses a barrel tube that is used to induce rotation to a projectile. The gun barrel as a whole constitutes an electric motor. The barrel tube is a permanent magnet and acts as the rotor of the motor. The stator coils of the motor are located outside the barrel tube and are used to induce rotation to the rotor, i.e., the barrel tube.

Abstract: A method for operating an electro-acoustic system (11) arranges an electro-acoustic device (10), for occluding an ear canal on an ear and uses a signal processing device (16) for processing a signal incoming at the device (10). A correction unit (17) of the signal processing device (16) modifies the signal incoming at the device (10). To reduce, to avoid or to compensate for an interfering or undesired change in a perception of ambient noises during the use of an electro-acoustic device occluding the ear canal, with the correction unit (17), a signal outgoing from the device (10) is generated in order to achieve acoustic transparency, in which, on the basis of the outgoing signal, a received signal is generated at the eardrum which is adapted so as to correspond to a free-ear received signal at the eardrum in the case of a free ear canal without the device (10).

Abstract: A gun barrel that consists of a frame tube (1) that encloses a barrel tube (2) that is used to induce rotation to a projectile. The gun barrel as a whole constitutes an electric motor such that the barrel tube (2) is a permanent magnet and acts as the rotor of said motor. The stator coils (3) of said motor are located outside the barrel tube (2) and are used to induce rotation to the rotor, i.e., the barrel tube (2).