  The present work is based on the COST Action IC1206 for De-identification in
multimedia content. It was performed to test four algorithms of voice
modifications on a speech gender recognizer to find the degree of modification
of pitch when the speech recognizer have the probability of success equal to
the probability of failure. The purpose of this analysis is to assess the
intensity of the speech tone modification, the quality, the reversibility and
not-reversibility of the changes made.
