A method of exchanging data packets between a first portable communication device and a second portable communication device over a bi-directional wireless communication channel, where at least one of the first and second portable communication devices comprises a hearing aid; said method comprising steps of: - generating, by the first portable communication device, a first data packet belonging to a first packet category (200a, 200b) comprising audio data or to a second packet category without audio data (200c, 200d), and adding an acknowledgement indicator with a default setting to the first data packet, - transmitting the first data packet from the first portable communication device to the second portable communication device through the wireless communication channel, - monitoring, at the first portable communication device, the wireless communication channel for a second data packet transmitted by the second portable communication device subsequent to receipt of the first data packet, - if the first portable communication device receives the second data packet: checking an error-detection code of the second data packet, and - if the error-detection code indicates uncorrupted data content of the second data packet and an acknowledgement indicator of the second data packet is set: - generating, at the first portable communication device, a third data packet comprising a set acknowledgment indicator reflecting receipt of the second data packet with uncorrupted data content at the first portable communication device; - transmitting the third data packet to the second portable communication device through the wireless communication channel; and - if the acknowledgement indicator of the second data packet is unset: setting the acknowledgment indicator of the first data packet to reflect receipt of the second data packet with uncorrupted data content at the first portable communication device and retransmitting the first data packet from the first to the second portable communication device; - if the error-detection code of the second data packet indicates corrupted data content of the second data packet: - unsetting the acknowledgment indicator of the first data packet and retransmitting the first data packet from the first to the second portable communication device; and - if the first portable communication device fails to receive the second data packet: - unsetting the acknowledgment indicator of the first data packet and retransmitting the first data packet from the first to the second portable communication device, wherein the retransmission of the first data packet is carried out for at the most N times if the first data packet belongs to the first packet category (200a, 200b); N being a positive integer between 1 and 4. - generating, by the first portable communication device, a first data packet belonging to a first packet category (200a, 200b) comprising audio data or to a second packet category without audio data (200c, 200d), and adding an acknowledgement indicator with a default setting to the first data packet, - transmitting the first data packet from the first portable communication device to the second portable communication device through the wireless communication channel, - monitoring, at the first portable communication device, the wireless communication channel for a second data packet transmitted by the second portable communication device subsequent to receipt of the first data packet, - if the first portable communication device receives the second data packet: checking an error-detection code of the second data packet, and - if the error-detection code indicates uncorrupted data content of the second data packet and an acknowledgement indicator of the second data packet is set: - generating, at the first portable communication device, a third data packet comprising a set acknowledgment indicator reflecting receipt of the second data packet with uncorrupted data content at the first portable communication device; - transmitting the third data packet to the second portable communication device through the wireless communication channel; and - if the acknowledgement indicator of the second data packet is unset: setting the acknowledgment indicator of the first data packet to reflect receipt of the second data packet with uncorrupted data content at the first portable communication device and retransmitting the first data packet from the first to the second portable communication device; - if the error-detection code of the second data packet indicates corrupted data content of the second data packet: - unsetting the acknowledgment indicator of the first data packet and retransmitting the first data packet from the first to the second portable communication device; and - if the first portable communication device fails to receive the second data packet: - unsetting the acknowledgment indicator of the first data packet and retransmitting the first data packet from the first to the second portable communication device, - unsetting the acknowledgment indicator of the first data packet and retransmitting the first data packet from the first to the second portable communication device; and - if the first portable communication device fails to receive the second data packet: - unsetting the acknowledgment indicator of the first data packet and retransmitting the first data packet from the first to the second portable communication device, - unsetting the acknowledgment indicator of the first data packet and retransmitting the first data packet from the first to the second portable communication device,