System and methods for rendering key respiratory measurements accessible to hand-held mobile electronic devices with acoustic input capabilities. A whistle having a pre-determined correlation (between through-flowing airflow per unit time and frequency of acoustic emissions from the whistle) may generate or transmit information or signals. A processor in the mobile electronic device may receive the information or signals, determine a baseline acoustic context, and/or record samples. The processor may determine a frequency value for an acoustic signal (based on the recorded samples), determine an expiratory airflow rate value (based on the frequency value), and determine a respiratory parameter (based on the expiratory airflow rate value). The processor may also determine whether the acoustic signal corresponds to a whistle signal that is generated by a user performing a forceful exhalation through the whistle. The processor may generate and render spirometric information.