That's the craziest pitch. Who is going to carry more stress in their voice: the dude who just scams for a living and is on his fifth phone call that hour or the guy with severe social anxiety who is only on this phone call because of the massive consequences accumulating from avoiding it?
I can almost believe it if it was something like detecting that a professional authorized agent wasn't being held at gunpoint. But having a consumer line say "You sound tense. I'm going to hang up and you can call back when you've calmed down." would... not be great.
Possibilities:
* the company had nobody competent enough internally to evaluate it because nobody competent will work for them (either due to money or working conditions) so the company operates in a self-reinforcing feedback loop of mediocrity
* the objective of introducing the system is not true security (because that would be hard/costly/raising uncomfortable questions) but to mislead the users into a false sense of security, scoring PR points among the clueless while avoiding the costly "true security" work
* some people internally will benefit from this system being introduced regardless of the actual value it provides, so any concerns will be ignored - by the time those problems come to light, whoever benefited would've moved on or even been promoted and is out of reach of the consequences
These are not mutually-exclusive.
Fraud detection from detecting stress in your voice however has no scientific basis, no matter how high the audio quality. There are tons of reasons for someone to be stressed that have nothing to do with fraud…
When I had tax trouble years ago I was constantly in a state of panic and stress on every phone call.