Angleton v. State
In Angleton v. State, 971 S.W.2d 65 (Tex. Crim. App. 1998), a witness heard both the original and enhanced audiotapes of a conversation.
He testified the enhanced copy of the tape only reduced background noise in the original tape and that the enhanced copy was an accurate copy of the relevant contents of the original tape.
The court held this testimony was sufficient to for the trial court to admit the enhanced tape as an accurate copy of the original. 971 S.W.2d at 67-68.