That is correct. US Federal law requires that at least one party (you), taking part in the call must be notified/aware of the recording. Most states require that same 1-party consent. What this boils down to: legally you don't have to inform the other person that you are recording the call. Ethically? That's up to you and your conscience. Other states require TWO-party consent. If a 3rd party records without consent/knowledge of the others, that's illegal and considered wiretapping, unless done by law enforcement, with a court order.