Earphone connection apparatus

1. A Remote Jack Unit (RJU) operative to connect both analogue and digital earphone devices to an aircraft In-Flight Entertainment and Communications (IFEC) server system providing a digital audio output, the RJU comprising:

an interface for connecting an earphone device to the server system;

a power supply for providing power to an earphone device when connected via the interface; and

a control module comprising:

a noise-cancellation module for providing noise-cancellation features to an earphone device when connected via the interface;

a detector for detecting a type of noise-cancelling arrangement to be implemented for the earphone device connected via the interface;

a converter for generating an analogue audio signal from the digital audio output received from the server system; and

a switch for switching between providing digital and analogue signals to the attached earphone device via the interface;

wherein the detector is configured to:

detect digital data on a data line indicative of a digital earphone device being connected to the RJU;

detect a high impedance on an audio line indicative of a powered noise-cancelling earphone device being connected to the RJU;

measure the impedance on a microphone line to determine whether the impendence on the microphone line is indicative of a non-powered active noise-cancelling earphone being connected to the RJU; and

detect a low impedance on an audio line indicative of a conventional analogue earphone device being connected to the RJU; and

wherein the control module is configured to:

supply digital signals to a connected earphone device when a digital earphone device is detected;

supply analogue audio signals to a connected earphone device when an analogue earphone device is detected;

connect the power supply to a connected earphone device when an earphone device requiring power is detected and to adjust the power supplied to the connected earphone device to suit the detected type of noise-cancelling arrangement; and

enable the noise-cancelling module when a non-powered active noise-cancelling earphone device is detected.

2. An RJU according to claim 1 , wherein the interface comprises a single connector operative to handle a plurality of signals.

3. An RJU according to claim 2 , wherein the connector is configured to provide two or more of the following signals: analogue audio; digital audio data; power; microphone input signal; earphone detection signal.

4. An RJU according to claim 1 , wherein the control module is configured to implement a plurality of different noise-cancelling arrangements and the control module is configured to implement a respective noise cancelling arrangement of the plurality of different noise-cancelling arrangements based upon the detected type of earphone device.

5. An RJU according to claim 1 , wherein the control module further comprises a network security module operative to allow only trusted digital earphone devices to connect with the IFEC server system.

6. An RJU according to claim 1 , wherein the control module is configured to detect a digital headphone connected to the interface and supply the digital headphone with 5V power and digital data from the IFEC server system.

7. An RJU according to claim 1 , wherein the control module is configured to detect an analogue powered noise-cancelling headphone of a type associated with an ARINC Type C1 or C2 connector and supply the analogue powered noise-cancelling headphone with 12V power and analogue audio signals.

8. An RJU according to claim 1 , wherein the control module is configured to detect an analogue non-powered noise-cancelling headphone of a type associated with an ARINC Type D1, D2 or D3 connector and supply the analogue non-powered noise-cancelling headphone with analogue audio signals while receiving analogue microphone signals from the analogue non-powered noise-cancelling headphone.

9. An RJU according to claim 1 , wherein the control module is configured to detect a standard analogue headphone of a type associated with an ARINC A1/B1 or A2/B2 connector and supply the standard analogue headphone with analogue audio signals.

10. An In-Flight Entertainment and Communications (IFEC) system comprising an RJU in accordance with claim 1 .