Files with vy4 suffix may possibly be voice recordings made using one of the Samsung devices. Proprietary codec.
VY4 file extension - Samsung voice codec file
What is vy4 file? How to open vy4 files?
File type specification:
File extension vy4 has been or still is used for one one of the many proprietary voice codecs used by Samsung. Most likely used in some recording device or smart phones.