A Full Frequency Masking Vocoder for Legal Eavesdropping Conversation Recording

Abstract: This paper presents a new approach for a vocoder design based on full frequency masking by octaves in addition to a technique for spectral filling via beta probability distribution. Some psycho-acoustic characteristics of human hearing- inaudibility masking in frequency and phase- are used as a basis for the proposed vocoder. The results confirm that this vocoder may be useful to save bandwidth in applications requiring intelligibility. It is recommended for the legal eavesdropping of long voice conversations. Introduction. The purpose of the voice compression is to obtain a concise representation of the signal, which allows efficient storage and transmission of voice data [1]. With proper processing, a voice signal can be analyzed and encoded at low data rates and then resynthesized. In many applications, the digital coding of voice is needed to introduce encryption algorithms (for security) or error correction techniques (to mitigate the noise of th