received by the International Bureau on 22 January 2019 (22.01.2019)

1. An electronic device, comprising:

a speaker;

a microphone;

one or more processors; and

memory storing one or more programs configured to be executed by the one or more processors, the one or more programs comprising instructions for:

while in a full-duplex live audio communication session with an external device, the full-duplex live audio communication session configured to transmit control signal data and separately transmit audio data:

receiving control signal data from the external device;

in response to receiving the control signal data:

issuing a perceptual notification; and

preventing audio input to the microphone from being enabled; after a first predetermined time period since receiving the control signal data, receiving audio data from the external device; and

after a second predetermined time period since issuing the perceptual notification, outputting the audio data from the speaker.

2. (Canceled).

3. The electronic device of claim 1, wherein the one or more programs further comprise instructions for:

in response to receiving the control signal data, preventing other applications on the electronic device from issuing perceptual notifications for a third predetermined time period.

4. The electronic device of any of claims 1 and 3, wherein the control signal data is received on a first channel, and wherein the audio data is received on a second channel that is different than the first channel.

5. The electronic device of any of claims 1 and 3, wherein the audio data comprises a plurality of audio data packets each having a header and a payload, and wherein the control signal data is encoded in the header of at least one audio data packet in the plurality of audio data packets.

6. The electronic device of any of claims 1 and 3-5, wherein the one or more programs further comprise instructions for:

enabling audio input to the microphone and outputting second control signal data to the external device.

7. The electronic device of claim 6, wherein audio input to the microphone is enabled a fourth predetermined time period after receiving a user input.

8. The electronic device of claim 6, wherein the one or more programs further comprise instructions for:

outputting second audio data to the external device a fourth predetermined time period after outputting the second control signal data.

9. The electronic device of claim 6, wherein the one or more programs further comprise instructions for:

determining if a user input occurred before the control signal data was generated based on clocking data within the control signal data.

10. The electronic device of claim 9, wherein the one or more programs further comprise instructions for:

in accordance with a determination that the user input occurred before the control signal data was generated, enabling audio input to the microphone and forgoing outputting the audio data from the speaker; and

in accordance with a determination that the user input occurred after the control signal data was generated, preventing audio input to the microphone from being enabled and outputting the audio data from the speaker.

11. The electronic device of any of claims 1 and 3-10, wherein the first predetermined time period and second predetermined time period have different lengths.

12. The electronic device of any of claims 1 and 3-10, wherein the first predetermined time period has the same length as the second predetermined time period.

13. The electronic device of any of claims 1 and 3-12, wherein the audio data is transmitted according to a voice over internet protocol (VoIP) standard selected from the group consisting of: FaceTime Audio, Real-Time Transfer Protocol, Secure Real-Time Transfer Protocol, Universal Datagram Protocol, and Transmission Control Protocol.

14. The electronic device of any of claims 1 and 3-13, wherein the control signal data is transmitted according to a voice over internet protocol (VoIP) standard selected from the group consisting of: Real-Time Transfer Control Protocol, Real-Time Transfer Protocol, and

Transmission Control Protocol.

15. (Currently Amended) A method, comprising:

at an electronic device with a speaker and a microphone:

while in a full-duplex live audio communication session with an external device, the full- duplex live audio communication session configured to transmit control signal data and separately transmit audio data: receiving control signal data from the external device;

in response to receiving the control signal data:

issuing a perceptual notification; and

preventing audio input to the microphone from being enabled;

after a first predetermined time period since receiving the control signal data, receiving audio data from the external device; and

after a second predetermined time period since issuing the perceptual notification, outputting the audio data from the speaker.

16. (Canceled).

17. The method of claim 15, further comprising:

in response to receiving the control signal data, preventing other applications on the electronic device from issuing perceptual notifications for a third predetermined time period.

18. The method of any of claims 15 and 17, wherein the control signal data is received on a first channel, and wherein the audio data is received on a second channel that is different than the first channel.

19. The method of any of claims 15 and 17, wherein the audio data comprises a plurality of audio data packets each having a header and a payload, and wherein the control signal data is encoded in the header of at least one audio data packet in the plurality of audio data packets.

20. The method of any of claims 15 and 17-19, further comprising:

enabling audio input to the microphone and outputting second control signal data to the external device.

21. The method of claim 20, wherein audio input to the microphone is enabled a fourth predetermined time period after receiving a user input.

22. The method of claim 20, further comprising:

outputting second audio data to the external device a fourth predetermined time period after outputting the second control signal data.

23. The method of claim 20, further comprising:

determining if a user input occurred before the control signal data was generated based on clocking data within the control signal data.

24. The method of claim 23, further comprising:

in accordance with a determination that the user input occurred before the control signal data was generated, enabling audio input to the microphone and forgoing outputting the audio data from the speaker; and in accordance with a determination that the user input occurred after the control signal data was generated, preventing audio input to the microphone from being enabled and outputting the audio data from the speaker.

25. The method of any of claims 15 and 17-24, wherein the first predetermined time period and second predetermined time period have different lengths.

26. The method of any of claims 15 and 17-24, wherein the first predetermined time period has the same length as the second predetermined time period.

27. The method of any of claims 15 and 17-26, wherein the audio data is transmitted according to a voice over internet protocol (VoIP) standard selected from the group consisting of:

FaceTime Audio, Real-Time Transfer Protocol, Secure Real-Time Transfer Protocol, Universal Datagram Protocol, and Transmission Control Protocol.

28. The method of any of claims 15 and 17-27, wherein the control signal data is transmitted according to a voice over internet protocol (VoIP) standard selected from the group consisting of: Real-Time Transfer Control Protocol, Real-Time Transfer Protocol, and Transmission Control Protocol.

29. A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with a speaker, the one or more programs including instructions for performing the method of any of claims 15 and 17-28.

30. An electronic device, comprising:

a speaker:

a microphone;

one or more processors; and

memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for performing the method of any of claims 15 and 17-28.

31. An electronic device, comprising:

a speakerff:]]^

a microphone; and

means for performing the method of any of claims 15 and 17-28.

32. A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device with a speaker and a microphone, the one or more programs including instructions for:

while in a full-duplex live audio communication session with an external device, the full- duplex live audio communication session configured to transmit control signal data and separately transmit audio data:

receiving control signal data from the external device;

in response to receiving the control signal data:

issuing a perceptual notification; and

preventing audio input to the microphone from being enabled;

after a first predetermined time period since receiving the control signal data, receiving audio data from the external device; and

after a second predetermined time period since issuing the perceptual notification, outputting the audio data from the speaker.

33. An electronic device, comprising:

a speaker;

a microphone; and

while in a full-duplex live audio communication session with an external device, the full- duplex live audio communication session configured to transmit control signal data and separately transmit audio data:

means for receiving control signal data from the external device; means, responsive to receiving the control signal data, for:

issuing a perceptual notification; and

preventing audio input to the microphone from being enabled;

means, after a first predetermined time period since receiving the control signal data, for receiving audio data from the external device; and

means, after a second predetermined time period since issuing the perceptual notification, for outputting the audio data from the speaker.

34. An electronic device, comprising:

one or more processors; and

memory storing one or more programs configured to be executed by the one or more processors, the one or more programs comprising instructions for:

receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device;

determining whether the contact is on a list; and

in accordance with a determination that the contact is on the list, establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request.

35. The electronic device of claim 34, wherein the one or more programs further comprise instructions for:

in accordance with a determination that the contact is not on the list, establishing the full- duplex audio communication session only if the user input is detected.

36. The electronic device of claim 34, wherein the one or more programs further comprise instructions for:

in accordance with a determination that the contact is not on the list, waiting for a user input that accepts the request.

37. The electronic device of any of claims 34-36, further comprising a microphone, and wherein the one or more programs further comprise instructions for:

in response to establishing the full-duplex live audio communication session, disabling audio input to the microphone.

38. The electronic device of any of claims 34-37, wherein the one or more programs further comprise instructions for:

in response to detecting a second user input, sending a second request to establish a second full-duplex live audio communication session between the electronic device and a second external device associated with a second contact; and

in response to sending the second request to the second external device, adding the second contact to the list.

39. A method, comprising:

at an electronic device:

receiving, from an external device associated with a contact, a request to establish a full- duplex live audio communication session between the electronic device and the external device; determining whether the contact is on a list; and

in accordance with a determination that the contact is on the list, establishing the full- duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request.

40. The method of claim 39, further comprising:

in accordance with a determination that the contact is not on the list, establishing the full- duplex audio communication session only if the user input is detected.

41. The method of claim 39, further comprising:

in accordance with a determination that the contact is not on the list, waiting for a user input that accepts the request.

42. The method of any of claims 39-41, wherein the electronic device includes a microphone, the method further comprising: in response to establishing the full-duplex live audio communication session, disabling audio input to the microphone.

43. The method of any of claims 39-42, further comprising:

in response to detecting a second user input, sending a second request to establish a second full-duplex live audio communication session between the electronic device and a second external device associated with a second contact; and

in response to sending the second request to the second external device, adding the second contact to the list.

44. A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device, the one or more programs including instructions for performing the method of any of claims 39-43.

45. An electronic device, comprising:

one or more processors; and

memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for performing the method of any of claims 39-43.

46. An electronic device, comprising:

means for performing the method of any of claims 39-43.

47. A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of an electronic device, the one or more programs including instructions for:

receiving, from an external device associated with a contact, a request to establish a full- duplex live audio communication session between the electronic device and the external device; determining whether the contact is on a list; and

in accordance with a determination that the contact is on the list, establishing the full- duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request.

48. An electronic device, comprising:

means for receiving, from an external device associated with a contact, a request to establish a full-duplex live audio communication session between the electronic device and the external device;

means for determining whether the contact is on a list; and 140

means, in accordance with a determination that the contact is on the list, for establishing the full-duplex live audio communication session between the electronic device and the external device, wherein the live audio communication session is established without receiving a user input that acknowledges the request.