An audio news release is a :60 packaged news piece including a :20 sound bite from a spokesperson that is pitched to stations over the phone. An audio bite line is sound—either an audio news release or a series of sound bites—that is placed on an 800 number line for stations to record. The primary difference between the two is pitching. Audio news releases are telephone pitched to targeted stations. An audio bite line is distributed by faxing or emailing an alert to stations about the availability of the story and audio, and if they are interested, the station will call in on the line.
Determining when each is used primarily depends on what your target audience is for the project and what your ultimate goals are for the message. If your objective is to reach a large number of stations in many markets in a short period of time, the audio bite line is the best service to utilize. If you have local information relevant to specific geographic areas and a smaller target audience, then the audio news release is the best service to use. Turnaround time for each service is quick, so either can be used in a breaking news situation.