This format extension is one of the Speex Audio formats. It is an open-source codec developed by Xiph.Org. Used for creating voice messages and transmitting voice over packet-based networks with a low level of security. It is an audio file with recorded voice messages that are packaged in an OGG file. Only certain media players can open it.

mp4

The format within the MPEG-4 Part 14 standard

Created in 1988, it was intended for video files. A file of this format contains video and audio information, images and subtitles. When compressed, the files do not lose quality. The format includes various types of multimedia content: videos, animations, audio, 2D and 3D graphics. Files of this format can be used and viewed on the Internet. In this case, a metadata transfer takes place. The full name of the format is MPEG-4 Part 14.