A MEMS transducer package (1) comprises a semiconductor die element (3) and a cap element (23). The semiconductor die element (3) and cap element (23) have mating surfaces (9, 21). The semiconductor die element (3) and cap element (23) are configured such that when the semiconductor die element (3) and cap element (4) are conjoined, a first volume (7, 27) is formed through the semiconductor die element (3) and into the semiconductor cap element (23), and an acoustic channel is formed to provide an opening between a non-mating surface (11) of the semiconductor die element (3) and a side surface (10, 12) of the transducer package.