The device on which the call recordings were originally recorded, becomes the primary evidence, which can be directly produced (in original) in court and it become admissible evidence.
But, you have said that call recordings were stored directly (and, perhaps, only) on the server in the cloud. In such a situation, that server in the cloud would become the primary evidence. Now, can you produce this original server in court? Obviously not. So, you have to give secondary evidence of the call recordings in court, by following the procedure / requirements of Section 65-B of the Evidence Act. If you follow these requirements, then such evidence may be admissible in court. But, admissibility of evidence is one thing, whether such evidence is genuine (and trustworthy) is entirely a different issue on which the court will decide taking into account various aspects.
Please read Section 65-B of the Evidence Act. There are various requirements under that provision which have to be satisfied. Certain information in respect of the server in the cloud where the information was stored, may also be needed. Certificate of the person mentioned in Section 65-B(4) is required to be given. Consult some local expert or lawyer if you cannot understand the requirements of Section 65-B yourself.
Secondary evidence can be in the form of copies on an electronic / magnetic / optical media as mentioned in the above legal provision. Transcript is only for the purpose of comparison and may have to be given if required by the court, though the above section does not require it.
You can request the judge to ask the complainant to provide her voice sample. But, as far as I understand, she may have the right to refuse.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.