Starting on Android KitKat (4.4), all downloaded apps must store their data on a designated folder on the SD Card.
In Hi-Q MP3 Voice Recorder, it is called App folder on SD Card. You can choose it when you change the Location of stored recordings.
The exact location of the folder on your SD card is: Android/data/com.hiqrecorder.full/files/Recordings
As for the Free version, the location is: Android/data/com.hiqrecorder.free/files/Recordings