Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal, including causing the source audio signal to be audibly output by an electroacoustic transducer of a user earpiece. The audio processing device records, while playing the source audio signal, a recorded audio signal using the electroacoustic transducer. The audio processing device identifies one or more parameters that indicate how properties of the user earpiece affect playing of the source audio signal, at least one of the parameters being temperature dependent. The audio processing device determines a temperature value estimated to cause the source audio signal that was played by the audio processing device to result in the recorded audio signal, accounting for changes to the source audio signal that occur due to the one or more parameters.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal, including causing the source audio signal to be audibly output by an electroacoustic transducer of a user earpiece. The audio processing device records, while playing the source audio signal, a recorded audio signal using the electroacoustic transducer. The audio processing device identifies one or more parameters that indicate how properties of the user earpiece affect playing of the source audio signal, at least one of the parameters being temperature dependent. The audio processing device determines a temperature value estimated to cause the source audio signal that was played by the audio processing device to result in the recorded audio signal, accounting for changes to the source audio signal that occur due to the one or more parameters.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal with an electroacoustic transducer of a user earpiece, and records an aural signal that is sensed by same said electroacoustic transducer. The audio processing device determines values of one or more features of the aural signal that indicate a characteristic of a space in which the user earpiece is located. The audio processing device compares the determined values of the one or more features of the aural signal with pre-defined values of the one or more features. Based on a result of the comparing, the audio processing device determines whether the user earpiece is located at a user's ear.

Abstract: According to some embodiments of the present invention there is provided a method of using an earphone output speaker as a microphone for a phone call between two and/or more participants, or for measuring biometric data of a user. The method may comprise playing a received signal to an electro-acoustic output transducer of an earphone. The method may comprise instructing an audio processing circuit of a local client terminal to record an audio signal from the same electro-acoustic output transducer. The method may comprise calculating a voice signal and/or a biometric measurement based on a function combining the recorded audio signal, the received signal, and filtration coefficients, using a processing unit of the local client terminal. The method may comprise sending the voice signal and/or a biometric measurement through an output interface of the local client terminal.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal with an electroacoustic transducer of a user earpiece, and records an aural signal that is sensed by same said electroacoustic transducer. The audio processing device determines values of one or more features of the aural signal that indicate a characteristic of a space in which the user earpiece is located. The audio processing device compares the determined values of the one or more features of the aural signal with pre-defined values of the one or more features. Based on a result of the comparing, the audio processing device determines whether the user earpiece is located at a user's ear.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal with an electroacoustic transducer of a user earpiece, and records an aural signal that is sensed by same said electroacoustic transducer. The audio processing device determines values of one or more features of the aural signal that indicate a characteristic of a space in which the user earpiece is located. The audio processing device compares the determined values of the one or more features of the aural signal with pre-defined values of the one or more features. Based on a result of the comparing, the audio processing device determines whether the user earpiece is located at a user's ear.

Abstract: A method of active noise reduction. The method comprises instructing a microphone electronically coupled by a client terminal to record a nonaural noise signal, instructing a circuit of the client terminal to record an aural noise signal using at least one electroacoustic transducer of an earphone, calculating a noise reduction signal based on a function combining nonaural noise signal and the aural noise signal, calculating a noise reduced signal based on a combination of a content signal prepared to be played by the at least one electroacoustic transducer and the noise reduction signal, and instructing the circuit to play the noise reduced signal via the at least one electroacoustic transducer. The nonaural noise signal and the aural noise signal are recorded at least partly simultaneously.

Abstract: According to an aspect of some embodiments of the present invention there is provided a method of recording a signal from a headphone. The method may comprise instructing an audio processing integrated circuit of a client terminal to connect an electrical resistance component between an electrical ground of a client terminal and an electrical ground of one or more electro-acoustic output transducer of a headphone. The method may further comprise instructing the audio processing integrated circuit of the client terminal to accept as microphone input a signal from the one or more electro-acoustic output transducer of the headphone. The method may further comprise recording a signal from the one or more electro-acoustic output transducer of the headphone using the audio processing integrated circuit of the client terminal.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal with an electroacoustic transducer of a user earpiece, and records an aural signal that is sensed by same said electroacoustic transducer. The audio processing device determines values of one or more features of the aural signal that indicate a characteristic of a space in which the user earpiece is located. The audio processing device compares the determined values of the one or more features of the aural signal with pre-defined values of the one or more features. Based on a result of the comparing, the audio processing device determines whether the user earpiece is located at a user's ear.

Abstract: According to some embodiments of the present invention there is provided a method of using an earphone output speaker as a microphone for a phone call between two and/or more participants, or for measuring biometric data of a user. The method may comprise playing a received signal to an electro-acoustic output transducer of an earphone. The method may comprise instructing an audio processing circuit of a local client terminal to record an audio signal from the same electro-acoustic output transducer. The method may comprise calculating a voice signal and/or a biometric measurement based on a function combining the recorded audio signal, the received signal, and filtration coefficients, using a processing unit of the local client terminal. The method may comprise sending the voice signal and/or a biometric measurement through an output interface of the local client terminal.

Abstract: According to some embodiments of the present invention there is provided a method of using an earphone output speaker as a microphone for a phone call between two and/or more participants, or for measuring biometric data of a user. The method may comprise playing a received signal to an electro-acoustic output transducer of an earphone. The method may comprise instructing an audio processing circuit of a local client terminal to record an audio signal from the same electro-acoustic output transducer. The method may comprise calculating a voice signal and/or a biometric measurement based on a function combining the recorded audio signal, the received signal, and filtration coefficients, using a processing unit of the local client terminal. The method may comprise sending the voice signal and/or a biometric measurement through an output interface of the local client terminal.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal with an electroacoustic transducer of a user earpiece, and records an aural signal that is sensed by same said electroacoustic transducer. The audio processing device determines values of one or more features of the aural signal that indicate a characteristic of a space in which the user earpiece is located. The audio processing device compares the determined values of the one or more features of the aural signal with pre-defined values of the one or more features. Based on a result of the comparing, the audio processing device determines whether the user earpiece is located at a user's ear.

Abstract: A method of active noise reduction. The method comprises instructing a microphone electronically coupled by a client terminal to record a nonaural noise signal, instructing a circuit of the client terminal to record an aural noise signal using at least one electroacoustic transducer of an earphone, calculating a noise reduction signal based on a function combining nonaural noise signal and the aural noise signal, calculating a noise reduced signal based on a combination of a content signal prepared to be played by the at least one electroacoustic transducer and the noise reduction signal, and instructing the circuit to play the noise reduced signal via the at least one electroacoustic transducer. The nonaural noise signal and the aural noise signal are recorded at least partly simultaneously.

Abstract: A method of active noise reduction. The method comprises instructing a microphone electronically coupled by a client terminal to record a nonaural noise signal, instructing a circuit of the client terminal to record an aural noise signal using at least one electroacoustic transducer of an earphone, calculating a noise reduction signal based on a function combining nonaural noise signal and the aural noise signal, calculating a noise reduced signal based on a combination of a content signal prepared to be played by the at least one electroacoustic transducer and the noise reduction signal, and instructing the circuit to play the noise reduced signal via the at least one electroacoustic transducer. The nonaural noise signal and the aural noise signal are recorded at least partly simultaneously.

Abstract: According to some embodiments of the present invention there is provided a method of using an earphone output speaker as a microphone for a phone call between two and/or more participants, or for measuring biometric data of a user. The method may comprise playing a received signal to an electro-acoustic output transducer of an earphone. The method may comprise instructing an audio processing circuit of a local client terminal to record an audio signal from the same electro-acoustic output transducer. The method may comprise calculating a voice signal and/or a biometric measurement based on a function combining the recorded audio signal, the received signal, and filtration coefficients, using a processing unit of the local client terminal. The method may comprise sending the voice signal and/or a biometric measurement through an output interface of the local client terminal.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal with an electroacoustic transducer of a user earpiece, and records an aural signal that is sensed by same said electroacoustic transducer. The audio processing device determines values of one or more features of the aural signal that indicate a characteristic of a space in which the user earpiece is located. The audio processing device compares the determined values of the one or more features of the aural signal with pre-defined values of the one or more features. Based on a result of the comparing, the audio processing device determines whether the user earpiece is located at a user's ear.

Abstract: According to some embodiments of the present invention there is provided a method of using an earphone output speaker as a microphone for a phone call between two and/or more participants, or for measuring biometric data of a user. The method may comprise playing a received signal to an electro-acoustic output transducer of an earphone. The method may comprise instructing an audio processing circuit of a local client terminal to record an audio signal from the same electro-acoustic output transducer. The method may comprise calculating a voice signal and/or a biometric measurement based on a function combining the recorded audio signal, the received signal, and filtration coefficients, using a processing unit of the local client terminal. The method may comprise sending the voice signal and/or a biometric measurement through an output interface of the local client terminal.

Abstract: According to some embodiments of the present invention there is provided a method of using an earphone output speaker as a microphone for a phone call between two and/or more participants, or for measuring biometric data of a user. The method may comprise playing a received signal to an electro-acoustic output transducer of an earphone. The method may comprise instructing an audio processing circuit of a local client terminal to record an audio signal from the same electro-acoustic output transducer. The method may comprise calculating a voice signal and/or a biometric measurement based on a function combining the recorded audio signal, the received signal, and filtration coefficients, using a processing unit of the local client terminal. The method may comprise sending the voice signal and/or a biometric measurement through an output interface of the local client terminal.

Abstract: According to an aspect of some embodiments of the present invention there is provided a method of recording a signal from a headphone. The method may comprise instructing an audio processing integrated circuit of a client terminal to connect an electrical resistance component between an electrical ground of a client terminal and an electrical ground of one or more electro-acoustic output transducer of a headphone. The method may further comprise instructing the audio processing integrated circuit of the client terminal to accept as microphone input a signal from the one or more electro-acoustic output transducer of the headphone. The method may further comprise recording a signal from the one or more electro-acoustic output transducer of the headphone using the audio processing integrated circuit of the client terminal.

Abstract: A method of active noise reduction. The method comprises instructing a microphone electronically coupled by a client terminal to record a nonaural noise signal, instructing a circuit of the client terminal to record an aural noise signal using at least one electroacoustic transducer of an earphone, calculating a noise reduction signal based on a function combining nonaural noise signal and the aural noise signal, calculating a noise reduced signal based on a combination of a content signal prepared to be played by the at least one electroacoustic transducer and the noise reduction signal, and instructing the circuit to play the noise reduced signal via the at least one electroacoustic transducer. The nonaural noise signal and the aural noise signal are recorded at least partly simultaneously.