Voice recognition V3 chip use

Hi all, I'm new to voice recognition V3. The source of this module is quite limited. Can anyone tell me that does this module use HM2007 chip?

I don't think so.

The HM2007 requires an external SRAM (64k bits, 8kx8) and can recognize 40 words. The elechouse VoiceRecognitionV3 has the memory built in and can only recognize 7 words at a time (selected from an 80-word vocabulary).

Then, what is the theory behind. Its possible to find? Because I need to know what is the chip use, the recognition method use, detection method use, decoder and so on.