Yes, the crowd was loud That's likely to be a result of the shape of the room. The speech was held in the lobby of Cincinnati's Union Terminal which is a giant half dome. I suspect that the crowd was a smaller than the "estimated 2600" people based on the curious lack of posted photographs of the crowd, the size of the room, and how the crowd looks in the photographs that are available.
One of the interesting features about the Union Terminal is the perfect sound reflection in the main lobby area which is a dome. For example, you can stand at the base of the arch on one side of the main entry doorway and whisper. Someone standing on the other end of the arch on the other side of the main door way can hear you. Quite interesting. The whole room is a perfect echo chamber.
Sound is substantially magnified. Likely why they chose the venue.