In some embodiments, a server establishes communication with user devices; the server receives location data identifying a location of each user device; the server determines a geographical region based on the location of each user device, each geographical region being different for user devices not at the same location; the server receives an audio stream from the first of the user devices; the server determines which of the other user devices are within the geographical region of the first user device; and the server transmits the audio stream to the other user devices that are within the geographical region of the first user device. In some embodiments, the server creates altered audio streams based on the distances between user devices. In some embodiments, the server changes the number of the other user devices that are within the geographical region of the first user device.