the present invention provides systems and methods for the communication of data over telephone lines . a handset orientation tolerant bi - directional acoustic modem according to the invention includes a first transducer operable as a receiving unit under a first condition and as a transmitting unit under a second condition , a second transducer operable as a transmitting unit under the first condition and as a receiving unit under the second condition , and a controller capable of determining the presence of one of the first and the second condition . the presence of the first condition or second condition depends on how the microphone and the speaker of a telephone handset are aligned with respect to the two transducers . the acoustic modem determines the alignment by listening for a detectable dial tone , and then under the first or the second condition , the acoustic modem automatically transmits data to a central site for analysis .