QCLEP, which may be known under a different name (Qualcomm PureVoice), is an audio file by PureVoice. It originally has been developed as a vocoder in 1994 in order to enhance the quality of speech in the CDMA networks. Later on, it has been replace by EVRC which is provides even better quality of speech, while using less bits. QCELP can be found in two versions, a 8 Kbit/s (QCELP8) and 13 Kbit/s (QCELP13) audio files. A QCELP vocoder is a device that provides variable rates, which makes it suitable for converting a sound signal, by extracting some voice feature parameters of a persons speech and transmit these to a peer party.