Pro-government media outlets have been churning out stories to disprove the authenticity of phone recordings allegedly between Prime Minister Recep Tayyip Erdoğan and his son Bilal on the morning of Dec. 17, when a corruption investigation became public with dawn raids, in which they discussed how to get rid of large sums of money stashed in the homes of Erdoğan's relatives; however, independent institutions and specialists on the matter claim that there is no way the tape recordings could have been doctored.
Audio engineer Kıvanç Kitapçı wrote on his self-named Wordpress blog that the recordings must be real as per analyses he hash conducted in his acoustics laboratory. He said there are be two methods of imitating a conversation. One of these methods is know as “copy and paste,” which means that an amalgamation of different words are cropped from previous speeches. For this to work, the pitch levels of the words need to be normalized, their frequencies should be synchronized and modulated, etc.; the final product, however, is patchy.
Kitapçı argues that generating fake audio recordings through this method is nearly impossible, and that the human ear for the most part can easily discern authenticity, without even needing a professional analyst.
The other method is to record the conversation of two different people who are good at imitating voices and manipulating the recording to make it sound authentic. He decided to check if the leaked recordings were a product of this type of fabrication.
Kitapçı, who calls himself a devoted specialist on speech acoustics and language processing technology, said he arbitrarily selected a sample of 20 easy words that are pronounced clearly in the voice recording. For the next step, he said, he spent almost five hours searching YouTube to find Erdoğan saying exactly the same words in other speeches that he has delivered before, to compare and contrast them and see whether they differ in what is called the fundamental frequency level, the raw sound that is created as air vibrates the vocal cords. Even a professional voice imitation needs to be done at the harmonic phase by modulating the sound after it passes the vocal cords. But the fundamental frequency is like a fingerprint, inimitable. So, using the Praat linguistic software, he made an F0 Contour measurement of the words he chose.
With a five percent margin of error, the result was that the voice in the recording in fact does belong to the prime minister.
Kitapçı was not alone. Reuters correspondent Ece Toksabay reported on Twitter that the owners of two İstanbul recording studios, Babajim Records and STD, separately found out through spectrogram analysis that the recordings had not been doctored.
Elsewhere, Tacidar Seyhan, a former Republican People's Party (CHP) deputy and specialist on information technology, said the conversations don't include any digitally derived sounds. “This is [their] original speech,” he said. He also criticized Erdoğan for using the term “dubbing” because that word refers to the addition of voice to an image. If he speaks of editing, it doesn't represent a denial of the conversation, Seyhan noted. He said merging different pieces of Erdoğan's previous speeches is definitely not present in the leaked tapes. “I meticulously analyzed them, listened to them over and over again,” he said.
Seyhan also added that Erdoğan has been complaining about wiretaps for years but has done nothing to prevent them until today and that therefore, “He is the last person to complain about them.”
The Sabah daily -- which was allegedly acquired by a businessman close to Erdoğan through a pool of funds from businessmen in return for favors in public tenders -- and the state-run Turkish Radio and Television Corporation (TRT) have claimed that the voice recordings were doctored, but they have failed to provide satisfactory technical analyses as to how they reached this conclusion. The Haber 7 online news portal also ran a story that was copied by a number TV stations on Tuesday evening, about a sound lab in the United States that analyzed the leaked tapes and found that the conversation had been copied from different speeches and pasted. The news didn't include the name of the studio or the method it used, however.
Officials responsible for cryptographic phones dismissed
In the meantime, Science, Technology and Industry Minister Fikri Işık fired five officials said to be in charge of cryptographic phones in the Scientific and Technological Research Council of Turkey's (TÜBİTAK) Research Center for Advanced Technologies on Informatics and Information Security (BİLGEM). Işık told reporters on Wednesday in İstanbul that the officials were sacked after Erdoğan's complaint that even his cryptographic phone was tapped, which was perceived as a confirmation that the controversial conversation actually took place and that the recordings were authentic. Işık said an administrative and a technical inspection has begun to look into it.