Assuming the use of a hidden voice recorder is legal, you can use it to record phone conversations. However, doing so may require additional equipment or software, as most phone conversations occur over a cellular network or a landline. Unless you’re using a speakerphone, recording a phone conversation requires the use of an external microphone or an adapter to connect the recorder directly to the phone line. Additionally, it is important to ensure that the recording quality is sufficient, and the recording device is hidden from the other party’s view during video calls, as they may object to being recorded.