This scam technique is known as the “Can you hear me?” scam.
A person would first receive a call and the caller would self-introduce as a company. Shortly after, the question
“Can you hear me?”
Naturally, one would reply “Yes”. The word “Yes” that you spoke has been recorded by the scammers.
Soon, this “yes” voice would be used against you by claiming that your voice has been used to agree to a verbal contract for purchasing some expensive garbage.
After declining that you did not agree to buy anything. The recorded voice “Yes” will use against you in court.