A communication passage in a Stirling cycle transducer includes a cylindrical shaped thermal regenerator providing flow paths aligned with a regenerator cylindrical axis for providing periodic gas flow between first and second interfaces of the regenerator. A first heat exchanger conveys gas between a periphery of the heat exchanger and the first interface causing a change of direction of gas flow between radially and axially oriented flow within the regenerator and transfers heat between the gas and an external environment in a direction aligned with the regenerator cylindrical axis. A second heat exchanger conveys gas between a periphery of the heat exchanger and the second interface causing a change of direction of gas flow between radially and axially oriented flow within the regenerator and transfers heat between the external environment and the gas in a direction aligned with the regenerator cylindrical axis.