This isn't actually from HNTB, it is an old number they used to have someone is re-using for scamming and the provider's caller ID is showing old information.
Came across as if a live person was going to come to the phone. I left it on speaker waiting so I could tell them to take me off of their list. It sounded like a radio talk show. After eight minutes no one had still come to the phone, my daughter and I were singing and dancing while we were waiting. I hung up. It was a good five minutes before I could make a call out because their end did not disconect. When I called their number back, 202.715.6661, it immediately returned to a talk radio show format, something to do with environmental concerns. I was too annoyed to pay close attention. Trust. I will follow up to their annoying interference into my daughter's life!!