think that you need 5 minutes record (and play) time
and your sample frequency is 8khz...
it means in one second you are saving 8bit*8000 data with 8bit adc without any compression algorithm..
for 5 minutes it makes 5*60*8000=2.4 megabyte... its too large...
perhaps you can decrease that using lower sample frequency but than qualyty of voice will decrease...
but in your case it is more appropriate to use a sound record/play chip...
i don't know much about them but isd chips are very popular: www.isd.com
and for their prices: www.digikey.com
Look for ISD Single-Chip Voice Record/Playback Devices.
They have build-in player, encoder/decoder and memory.
Maybe they are litle expensive, but it worth.
It's not on a PIC and it's not in EEprom, but here is my project for an AVR record & playing from an MMC/SD or CF or harddisk https://mcselec.com/forum/viewtopic.php?t=683
Did you know 33min * 60sec per min = 1980sec at a sample rate of 8k per sec mono = 1980 * 8000 is greater than 15M. If you apply compression you can reduce this.