How to export my Iphone6s voice memos?

See: https://support.apple.com/en-us/HT206775

There is a section on using the Share icon to export the voice memo.

The quickest would be to email them to yourself, but for all at once there’s no native solution, like batch export. You can sync them to Mac or PC as well and play them in Tunes: http://www.idownloadblog.com/2014/02/23/how-to-transfer-voice-memos-iphone-compu ter

If you consider using third party utility, you could use iMaizing for export. it's pretty straightforward, and you can get actual audio files on your device. You will need to install the app, make a backup, select Voice memos and select Export.