Do you know the voices of your second or third degree relatives? Telephone scams are quite a well organized crime by now in Germany. If they can extend the target audience from elderly people to the general public by this means, they dont really care about some negative contacts.

http://www.aarp.org/money/scams-fraud/info-2016/how-to-beat-... https://de.wikipedia.org/wiki/Enkeltrick

If they really need a voice sample from a relative they could still impost, with voice or not, as insurance person, HR or police and acquire it by simple means if they have any idea about the social graph of their victim.