Yeah I had the same call. While you don't consider it spam, do understand that it could be taking a sample of your voice to use in voice-activated system. Never speak to an unknown number before they do.

Have had multiple calls from this number. There was no caller when I answered and "not available at this time" the time I called back. Not really as scam if they don't try to scam you. More like some sort of nuisance call.