Low power intermittent messaging for hearing assistance devices

A method for hearing assistance device communications between a transmitter having a first clock and a receiver having a second clock, the method comprising:

• synchronizing the first clock, having a first frequency drift, and the second clock, having a second frequency drift, at a synchronization time;
• determining a time interval between the synchronization time and a transmission time of a transmission, wherein the transmission includes a packet;
• calculating a drift window using an initial drift window and a potential drift amount between the first clock and the second clock over the time interval including using a calculation of a number of sleep window intervals between the transmission and a second transmission, wherein the initial drift window is a product of a sleep interval and clock accuracy;
• and
• transmitting the transmission with the transmitter on a first channel, wherein the packet includes a packet length based on the first frequency drift and the second frequency drift and a preamble having a preamble length less than or equal to a duration of the drift window;
• and
• retransmitting the transmission on a second channel when the receiver does not receive the packet on the first channel.