The world we live in is not always what it seems. Simply put, just answering the phone can expose you to dangers from scam artists. The best we can all do is learn about the dangers so as to be ready to face them on a daily basis.
The "can you hear me" scam is a new scam that essentially uses the simple question in order to elicit the word "yes" from the phone call recipient. A scammer calls someone, and when the person answers, the scammer, who is recording the call, asks: Can you hear me? Once the scammer is able to record a person saying "yes," they will be able to use that recorded answer to potentially push through fraudulent credit charges either via a person's phone bill or credit card.
Don't Try to Outsmart Scammers
While saying "no" initially may seem like a clever way to thwart the scammers, there may be follow up questions that test your ability to avoid saying the word "yes," or providing some other form of affirmative response. The more you say, the more words the scammer may be able to put in your mouth at a later date. Generally, the best way to avoid the scam is to hang up the phone if you are unsure of the identity of the caller.
Notably, because scammers can spoof their caller ID number, a call coming from an official government or business line may be fraudulent. What makes this type of scam so frightening is the sheer simplicity of it. A scammer can ask nearly any questions designed to get a 'yes' answer, and use that to commit fraud or identity theft.
However, the best practice may be to change phone habits and avoid using the word yes, after all, this is the world we live in now. As we've had to change our e-mail habits due to the many different forms of phishing scams, it's probably time phone habits changed, if they haven't already. Be skeptical of anyone calling you asking for information, particularly government officials as most government communication is done via mail.
If you think you've been a victim of this scam, you should check your phone bills or credit card statements for unauthorized charges. Also, you may want to obtain a detailed credit report to see if there are unfamiliar marks on your credit history.