Abstract: A method of controlling a personal acoustic device includes generating a first electrical signal responsive to an acoustic signal incident at a microphone disposed at a location on an earpiece of the personal acoustic device such that the microphone is acoustically coupled to an environment external to the earpiece. A characteristic of a transfer function based on the first electrical signal and a second electrical signal provided to a speaker in the earpiece is determined. An operating state of the personal acoustic device is determined form the characteristic of the transfer function. The operating state include a state in which the earpiece is positioned in the vicinity of an ear of a user and a second state in which the earpiece is absent from the vicinity of the ear of the user.

Abstract: A headset includes at least one ear cup having front and rear cavities separated by a driver. The cup includes a pressure equalization port coupling the front cavity to space outside the cup, the pressure equalization port having a cross-sectional area greater than 2 mm2 and being significantly longer than it is wide, providing a principally reactive acoustic impedance, such that the pressure response of the front cavity including the port to signals input via the driver may be effectively linear over a wide range of pressure levels within the front cavity.

Abstract: A method of controlling a personal acoustic device includes generating a first electrical signal responsive to an acoustic signal incident at a microphone disposed at a location on an earpiece of the personal acoustic device such that the microphone is acoustically coupled to an environment external to the earpiece. A characteristic of a transfer function based on the first electrical signal and a second electrical signal provided to a speaker in the earpiece is determined. An operating state of the personal acoustic device is determined form the characteristic of the transfer function. The operating state include a state in which the earpiece is positioned in the vicinity of an ear of a user and a second state in which the earpiece is absent from the vicinity of the ear of the user.

Abstract: A headphone includes an electroacoustic transducer and a support structure for suspending the transducer adjacent to a user's ear when worn by the user such that the headphone is acoustically open. A first microphone is coupled to one or more of the transducer and the support structure such that the first microphone is located in a substantially broadband acoustic null of the transducer. A processor is coupled to the headphone. The microphone receives sound pressure waves and outputs a related electronic signal to the processor. The processor uses the electronic signal to operate the transducer to reduce targeted sound pressure waves at the user's ear.

Abstract: A headphone includes an electroacoustic transducer and a support structure for suspending the transducer adjacent to a user's ear when worn by the user such that the headphone is acoustically open. A first microphone is coupled to one or more of the transducer and the support structure such that the first microphone is located in a substantially broadband acoustic null of the transducer. A processor is coupled to the headphone. The microphone receives sound pressure waves and outputs a related electronic signal to the processor. The processor uses the electronic signal to operate the transducer to reduce targeted sound pressure waves at the user's ear.

Abstract: A method of controlling a personal acoustic device includes generating a first electrical signal responsive to an acoustic signal incident at a microphone disposed on an earpiece of the personal acoustic device. A characteristic of a transfer function based on the first electrical signal and a second electrical signal provided to a speaker in the earpiece is determined. An operating state of the personal acoustic device is determined form the characteristic of the transfer function. The operating state include a state in which the earpiece is positioned in the vicinity of an ear of a user and a second state in which the earpiece is absent from the vicinity of the ear of the user. Examples of a microphone that may be used include feedback and feedforward microphones in an acoustic noise reduction circuit.

Abstract: A headphone that has a support structure that is adapted to sit on a head or upper torso of a user, a first acoustic driver carried by the support structure such that the first acoustic driver is located off of an ear of the user, wherein the first acoustic driver has front and rear sides and sound is radiated from both sides of the first acoustic driver, and a structure that defines a first acoustic chamber on the front side of the first acoustic driver and with at least one opening therein, and a second acoustic chamber on the rear side of the first acoustic driver and with at least one opening therein. At low frequencies a polar pattern of the first acoustic driver behaves approximately like a dipole, and at high frequencies a polar pattern of the first acoustic driver exhibits a higher order directional pattern. A second acoustic driver can be included.

Abstract: A headphone that has a support structure that is adapted to sit on a head or upper torso of a user, a first acoustic driver carried by the support structure such that the first acoustic driver is located off of an ear of the user, wherein the first acoustic driver has front and rear sides and sound is radiated from both sides of the first acoustic driver, and a structure that defines a first acoustic chamber on the front side of the first acoustic driver and with at least one opening therein, and a second acoustic chamber on the rear side of the first acoustic driver and with at least one opening therein. At low frequencies a polar pattern of the first acoustic driver behaves approximately like a dipole, and at high frequencies a polar pattern of the first acoustic driver exhibits a higher order directional pattern. A second acoustic driver can be included.

Abstract: A headphone that has a support structure that is adapted to sit on a head or upper torso of a user, a first acoustic driver carried by the support structure such that the first acoustic driver is located off of an ear of the user, wherein the first acoustic driver has front and rear sides and sound is radiated from both sides of the first acoustic driver, and a structure that defines a first acoustic chamber on the front side of the first acoustic driver and with at least one opening therein, and a second acoustic chamber on the rear side of the first acoustic driver and with at least one opening therein. At low frequencies a polar pattern of the first acoustic driver behaves approximately like a dipole, and at high frequencies a polar pattern of the first acoustic driver exhibits a higher order directional pattern. A second acoustic driver can be included.

Abstract: A headphone that has a support structure that is adapted to sit on a head or upper torso of a user, a first acoustic driver carried by the support structure such that the first acoustic driver is located off of an ear of the user, wherein the first acoustic driver has front and rear sides and sound is radiated from both sides of the first acoustic driver, and a structure that defines a first acoustic chamber on the front side of the first acoustic driver and with at least one opening therein, and a second acoustic chamber on the rear side of the first acoustic driver and with at least one opening therein. At low frequencies a polar pattern of the first acoustic driver behaves approximately like a dipole, and at high frequencies a polar pattern of the first acoustic driver exhibits a higher order directional pattern. A second acoustic driver can be included.

Abstract: A convertible headphone system with headphones having a transducer with a front and a rear, and a back cavity that is fluidly coupled to the rear of the transducer, and an external acoustic structure that defines an acoustic volume. The headphones and the external acoustic structure are configured to be coupled together so as to fluidly couple the back cavity of the headphones to the acoustic volume of the external acoustic structure, to form an expanded back cavity volume.

Abstract: A convertible headphone system with headphones having a transducer with a front and a rear, and a back cavity that is fluidly coupled to the rear of the transducer, and an external acoustic structure that defines an acoustic volume. The headphones and the external acoustic structure are configured to be coupled together so as to fluidly couple the back cavity of the headphones to the acoustic volume of the external acoustic structure, to form an expanded back cavity volume.

Abstract: A headphone includes an electro-acoustic transducer dividing an enclosed volume into a front volume and a rear volume, a first port in the housing coupling the front volume to an ear canal of a user, a second port in the housing coupling the front volume to space outside the ear, a third port in the housing coupling the rear volume to space outside the ear, and an ear tip configured to surround the first port and including a flap to seal the ear canal from space outside the ear. The second port has a diameter and a length that provide an acoustic mass with an acoustic impedance with a high reactive component and a low resistive component, reducing the occlusion effect that otherwise results from sealing the ear.

Abstract: A headphone includes an electro-acoustic transducer dividing an enclosed volume into a front volume and a rear volume, a first port in the housing coupling the front volume to an ear canal of a user, a second port in the housing coupling the front volume to space outside the ear, a third port in the housing coupling the rear volume to space outside the ear, and an ear tip configured to surround the first port and including a flap to seal the ear canal from space outside the ear. The second port has a diameter and a length that provide an acoustic mass with an acoustic impedance with a high reactive component and a low resistive component, reducing the occlusion effect that otherwise results from sealing the ear.

Abstract: A headset includes at least one ear cup having front and rear cavities separated by a driver. The cup includes a pressure equalization port coupling the front cavity to space outside the cup, the pressure equalization port having a cross-sectional area greater than 2 mm2 and being significantly longer than it is wide, providing a principally reactive acoustic impedance, such that the pressure response of the front cavity including the port to signals input via the driver may be effectively linear over a wide range of pressure levels within the front cavity.