Speech-encoding at low bitrate with AAC?

[Forteen88]

I'm trying to find out what type of setting I should use to encode audio (speech mostly) at ~64kbps with Apple AAC-codec.
Is Apple CVBR (Constrained VBR), with HE-AAC enabled, better to use when encoding low bitrate, than using normal Apple VBR (also called TVBR, I think. LC-AAC)?

This ABX-test uses Apple CVBR (with HE-AAC enabled) and not normal Apple VBR (also called TVBR, I think) when comparing codecs at low bitrate,
"Public Multiformat Listening Test @ ~64 kbps (March 2011)",
http://listening-tests.hydrogenaud.i...@%2064kbps.htm

At 96kbps bitrate, IgorC wrote this though:

TVBR - --tvbr 46 - real bitrate ~94-95 kbps - have score 4,391 in public test
CVBR --cvbr 96 - real bitrate ~100-101 kbps - score is 4,342.

It's bitrate variation. Both CVBR and TVBR are pretty the same.
Use any of them.

https://hydrogenaud.io/index.php/topic,113542.0.html

EDIT: Thanks for the answer tebasuna51 & SeeMoreDigital!