Than why didn`t you provided the recording to investigation officer while investigation. File application in court to take on record, voice recording and than file discharge application.

In Some Cases, Trial Court Can Summon Or Rely Upon Documents Not Part Of Charge Sheet:

You can go for quashing in high court on the basis of that recording.  You can file case against them for false prosecution and claim compensation

As tge chargw sheet has been submitted and the trial has begun file an application in tge high court for quashing of the charge sheet.

If it doesn't then the trial will go on.

Regards 

1.  The recording on the Mobile instrument is a key evidence in your favor.

2.  Give the Mobile to local Forensic Expert for his opinion and report on the genuineness & transcript of the recording.

3.  Produce the Mobile, the Report & the Transcript, in court during trial and cross-examine the person on election duty.

4.  The above would get you a clean acquittal into the false case.

File petition for quashing in HC 

in alternative file for discharge before trial court 

See first the prosecution witness shall be recorded in same you can cross examine there witness in your defense witness you can produce the recorded video along with the 65-B certificate before the court and court may take same on record.

You should hv file a quashing petition before the high court. 

Now you can file revision against charge on the basis of recording

Dear,

       As you mentioned you have proof of voice recording of that day,

       you should provide this detail to your lawyer and investing office of your case.

       Charge sheet is filed, so file writ in high court for quashing it.

you can directly file the quashing of FIR in the High court.