Saving a voicemail greeting from someone who has passed away

Hi - a family member passed away and I want to save their custom voicemail greeting to voice memos. The family member’s phone number was transferred to my iPhone because it is also a family business phone number. I need to record a new custom greeting for the business, but I also want to keep the current one in memos to remember the voice of the person who passed away. I have tried playing it out loud ok the phone speaker and recording on a different device but the quality of the recording is significantly reduced because you are simply recording all the sound in the room and the best volume an iPhone speaker can muster - sounds pretty bad! There MUST be a better solution. Help!