Use your Smartphone to record birds in the field. You will need a recording App for either an iPhone or Android Smartphone. There are numerous options and you can use just about any of them for this project to make recordings in the field. Here is a brief outline of what you need to do to get started.
Choose a recording App appropriate to your phone and operating system. The free Apps are just as good as the ones you pay for. They may have fewer options but most of them will record birds and provide sound files needed for this study. Some examples I have used are: VoiceMemo, iTalk, RecorderApp on the iPhone.
Record the bird using the highest quality settings available in your App (wav file format, 16-bit or higher, 44.1kHz if these settings are available). Get as close to the bird as possible without disturbing it. I usually record it immediately so I have something, and then proceed to get closer for better recordings. Orient the microphone of the Smartphone towards the bird.
Try saving the sounds files in AIFF or wav file formats. They are the easiest to process.
Send the files to the Mourning Warbler Sound Lab to my e-mail address. This part can be the most problematic depending on your recording App. Some Apps will let you e-mail the sound files directly from within the App. An alternative I have found is connecting my iPhone to my computer’s USB port and using iTunes. Using iTunes is an easy way to transfer file directly to my computer. I am not sure how it works with the Android Smartphones but each App should have some documentation on file exchange.