usually voice recordings would generally be accepted provided you can prove their genuineness and authenticity. You may have to show that the voice recordings are not manipulated and are of the same person whose voice you claim it to be.
n the case of Ram Singh v. Col. Ram Singh, AIR 1986 SC 3, following conditions were pointed out by the Apex Court for admissibility of tape recorded conversation:
a) the voice of the speaker must be duly identified by the maker of the record or by others who recognize his voice. Where the maker has denied the voice it will require very strict proof to determine whether or not it was really the voice of the speaker.
b) The accuracy of the tape recorded statement has to be proved by the maker of the record by satisfactory evidence direct or circumstantial.
c) Every possibility of tempering with or erasure of a part of a tape recorded statement must be ruled out otherwise it may render the said statement out of context and, therefore, inadmissible.
d) The statement must be relevant according to the rules of Evidence Act.
e) The recorded cassette must be carefully sealed and kept in safe or official custody.
f) The voice of the speaker should be clearly audible and not lost or distorted by other sounds or disturbance.