Anti-spoofing: Voice conversion

Voice conversion is a process which converts or transforms one speaker's voice towards that of another. The literature shows that voice conversion can be used to spoof or fool an automatic speaker verification system. State-of-the-art voice conversion algorithms can produce high-quality speech signals in real time and are capable of fooling both human listeners and automatic systems, including text-independent and text-dependent. Furthermore, since converted voice originates from a living person, traditional liveness detection countermeasures are not necessarily effective in detecting such attacks. With today's state-of-the-art algorithms producing high-quality speech with only few indicative processing artifacts, the detection of converted voice can be especially challenging.