Abstract: Engineered, pseudo-crystalline materials are formed of repeating arrays or lattices of similar basic elements. The materials are porous, so that a gas such as air can pass through the material. Audio waves propagating through the gas can also pass through the material, and these waves experience a passive, uneven, frequency-dependent modification as a result of passing through the material. The frequency response of this modification can be tuned by selecting the shape, size, and repetition patterns of the basic elements in the lattice, as well as the ingredients from which the pseudo-crystalline materials are made.

Abstract: Engineered, pseudo-crystalline materials are formed of repeating arrays or lattices of similar basic elements. The materials are porous, so that a gas such as air can pass through the material. Audio waves propagating through the gas can also pass through the material, and these waves experience a passive, uneven, frequency-dependent modification as a result of passing through the material. The frequency response of this modification can be tuned by selecting the shape, size, and repetition patterns of the basic elements in the lattice, as well as the ingredients from which the pseudo-crystalline materials are made.

Abstract: Custom in-ear monitors (headsets, headphones, earbuds, hearing aids) having improved audio fidelity characteristics and improved manufacturability are constructed by designing a virtual three-dimensional model housing including sound and vent tubes, and equipment mounting receptacles and clips; and fabricating the housing substantially simultaneously or all-in-one-go using, e.g., a 3D printer. The sound and vent tubes comprise features such as inflection points and profile variations that are impossible to construct using traditional subtractive manufacturing processes.

Abstract: Custom in-ear monitors (headsets, headphones, earbuds, hearing aids) having improved audio fidelity characteristics and improved manufacturability are constructed by designing a virtual three-dimensional model housing including sound and vent tubes, and equipment mounting receptacles and clips; and fabricating the housing substantially simultaneously or all-in-one-go using, e.g., a 3D printer. The sound and vent tubes comprise features such as inflection points and profile variations that are impossible to construct using traditional subtractive manufacturing processes.

Abstract: A personal listening device including at least one direct-radiating balanced-armature audio transducer and at least one substantially enclosed, indirect-radiating, or tube-coupled balanced-armature transducer. The tube-connected transducer emits sound waves which pass through a hole, slot, tube or bore before entering an airspace near the eardrum of a user, while the direct-radiating transducer emits sound waves directly into the airspace adjacent the indirect-radiating transducer or tube, which airspace is contiguous with the airspace near the eardrum of the user.

Abstract: Audio reproduction devices, including without limitation headphones, universal in-ear monitors and custom in-ear monitors, are improved by electrical design that targets a flat electrical impedance across a predetermined frequency range such as the typical audible range of 20 Hz-20 kHz. Headphones and earphones having a flat or linear electrical impedance characteristic will have more consistent audio performance when driven by different sources.

Abstract: Custom in-ear monitors (headsets, headphones, earbuds, hearing aids) having improved audio fidelity characteristics and improved manufacturability are constructed by designing a virtual three-dimensional model housing including sound and vent tubes, and equipment mounting receptacles and clips; and fabricating the housing substantially simultaneously or all-in-one-go using, e.g., a 3D printer. The sound and vent tubes comprise features such as inflection points and profile variations that are impossible to construct using traditional subtractive manufacturing processes.

Abstract: In-ear monitors, earphones and noise-attenuating earplugs are provided with a vent to improve insertion, removal and wearing comfort, and to protect delicate audio drivers from excessive pressure excursions. The vent is fitted with a pressure-management material such as a viscoelastic open-cell foam to control the rate at which air can pass through the vent. The pressure-management material permits tuning of the vent to achieve acoustically flat attenuation of ambient sound.

Abstract: Audio reproduction devices, including without limitation headphones, universal in-ear monitors and custom in-ear monitors, are improved by electrical design that targets a flat electrical impedance across a predetermined frequency range such as the typical audible range of 20 Hz-20 kHz. Headphones and earphones having a flat or linear electrical impedance characteristic will have more consistent audio performance when driven by different sources.

Abstract: Custom in-ear monitors (headsets, headphones, earbuds, hearing aids) having improved audio fidelity characteristics and improved manufacturability are constructed by designing a virtual three-dimensional model housing including sound and vent tubes, and equipment mounting receptacles and clips; and fabricating the housing substantially simultaneously or all-in-one-go using, e.g., a 3D printer. The sound and vent tubes comprise features such as inflection points and profile variations that are impossible to construct using traditional subtractive manufacturing processes.

Abstract: A personal listening device including at least one direct-radiating balanced-armature audio transducer and at least one substantially enclosed, indirect-radiating, or tube-coupled balanced-armature transducer. The tube-connected transducer emits sound waves which pass through a hole, slot, tube or bore before entering an airspace near the eardrum of a user, while the direct-radiating transducer emits sound waves directly into the airspace adjacent the indirect-radiating transducer or tube, which airspace is contiguous with the airspace near the eardrum of the user.

Abstract: In-ear monitors, earphones and noise-attenuating earplugs are provided with a vent to improve insertion, removal and wearing comfort, and to protect delicate audio drivers from excessive pressure excursions. The vent is fitted with a pressure-management material such as a viscoelastic open-cell foam to control the rate at which air can pass through the vent. The pressure-management material permits tuning of the vent to achieve acoustically flat attenuation of ambient sound.