Since security for various financial services often includes texting a pass code to your phone, it is very important that we prevent hackers from porting our phone numbers to another device.
Here is a link that explains speaker verification, which is what I mean when I say "voice signature" in the title of this post.
In terms of the problem I am trying to solve, I think the first few lines of the following article describe the issue best:
Hackers have discovered that one of the most central elements of online security — the mobile phone number — is also one of the easiest to steal.
In a growing number of online attacks, hackers have been calling up Verizon, T-Mobile U.S., Sprint and AT&T and asking them to transfer control of a victim’s phone number to a device under the control of the hackers.
Once they get control of the phone number, they can reset the passwords on every account that uses the phone number as a security backup — as services like Google, Twitter and Facebook suggest.
I suppose this may be expensive to implement, but I think it is a big competitive advantage for Ting to add extra security to prevent malicious phone number porting.
Thank you for seriously considering my request.