A device (100, 200, 300, 400, 500, 600, 700) comprising: a package substrate (130, 230, 530, 630, 730) and a lid (108, 608) attached to the package substrate (130, 230, 530, 630, 730) forming a package; a MEMS acoustic sensor (102, 502, 702) disposed in the package; an application specific integrated circuit, ASIC, disposed in the package and comprising an ASIC substrate (112, 212, 450, 550) having an environmental sensing material (105, 205, 305, 405, 505, 805, 905) of an environmental sensor (404, 504, 800, 900) disposed in the ASIC substrate (112, 212, 450, 550), wherein the environmental sensor (404, 504, 800, 900) comprises the environmental sensing material (105, 205, 305, 405, 505, 805, 905) in a configuration sensitive to a change in an environmental characteristic independent of pressure experienced by the environmental sensor (404, 504, 800, 900), wherein the environmental sensor (404, 504, 800, 900) is comprised of a plurality of segments of the environmental sensing material (105, 205, 305, 405, 505, 805, 905) interspersed between and in direct contact with a plurality of metal electrodes (801, 803, 901, 910), wherein the plurality of metal electrodes (801, 803, 901, 910) are subjected to a variable electrical environment in response to the change in the environmental characteristic, wherein at least one of the plurality of metal electrodes comprises a heating element (803, 910) of the environmental sensor (404, 504, 800, 900), and wherein the ASIC is configured to process data generated by the environmental sensor (404, 504, 800, 900) and data generated by the MEMS acoustic sensor (102, 502, 702); and a port (106, 606, 706) disposed in the package configured to receive acoustic waves for the MEMS acoustic sensor (102, 502, 702) and air for the environmental sensor (404, 504, 800, 900); wherein, the package includes an acoustically sealed back cavity (134, 234, 334) associated with the MEMS acoustic sensor (102, 502, 702). a package substrate (130, 230, 530, 630, 730) and a lid (108, 608) attached to the package substrate (130, 230, 530, 630, 730) forming a package; a MEMS acoustic sensor (102, 502, 702) disposed in the package; an application specific integrated circuit, ASIC, disposed in the package and comprising an ASIC substrate (112, 212, 450, 550) having an environmental sensing material (105, 205, 305, 405, 505, 805, 905) of an environmental sensor (404, 504, 800, 900) disposed in the ASIC substrate (112, 212, 450, 550), wherein the environmental sensor (404, 504, 800, 900) comprises the environmental sensing material (105, 205, 305, 405, 505, 805, 905) in a configuration sensitive to a change in an environmental characteristic independent of pressure experienced by the environmental sensor (404, 504, 800, 900), wherein the environmental sensor (404, 504, 800, 900) is comprised of a plurality of segments of the environmental sensing material (105, 205, 305, 405, 505, 805, 905) interspersed between and in direct contact with a plurality of metal electrodes (801, 803, 901, 910), wherein the plurality of metal electrodes (801, 803, 901, 910) are subjected to a variable electrical environment in response to the change in the environmental characteristic, wherein at least one of the plurality of metal electrodes comprises a heating element (803, 910) of the environmental sensor (404, 504, 800, 900), and wherein the ASIC is configured to process data generated by the environmental sensor (404, 504, 800, 900) and data generated by the MEMS acoustic sensor (102, 502, 702); and a port (106, 606, 706) disposed in the package configured to receive acoustic waves for the MEMS acoustic sensor (102, 502, 702) and air for the environmental sensor (404, 504, 800, 900); wherein, the package includes an acoustically sealed back cavity (134, 234, 334) associated with the MEMS acoustic sensor (102, 502, 702).