They believe it generates more bids, but that's questionable. Sotheby's and Christy's seem to do fine while speaking clearly and slowly. Over time, it gets easier to understand them.
People sometimes get the fever, but most times we know what we want to pay and stick close to that number.
I understand them most of the time, it's like they are singing a song, and I wear earplugs. Earplugs would be required by OSHA if I worked for someone else, I know because sometimes ear plugs aren't enough. That is loud.
Once in a while, they will be repeating 25, 25, 25, but a few seconds before, they had said 125, so if someone wasn't paying close attention, they say: "I'll take that thing for 25". Then, not wanting to be the focus of attention when they say I don't want that for 125, go ahead and act like they meant to bid 125. Not a scam, but it's not straight forward and works to deceive. The auctioneers act put out that the show was stopped and the clerk has to scribble out what they just wrote, but what do they expect when they are mostly saying yabba, yabba, yabba.
I go after "cancer eye cows". It's a reference to Scalpers who buy cows with defects, nurse them back to health, i.e. remove the cancerous eye, let it heal, then take it back to sale barn making money. I go after things nobody wants that day.
In the last few years, I bought and drove home a 1966 T-Bird 428 for $800, a 1966 Satellite 383/4speed for $300 that I had running in 2 hours, a 73 GT6+ for $138, and 1978 Camry GT for $1.
The auctioneer was rude to me earlier so I was tougher with my money or I might have bid $10. When the Camry came up and no one bid 1,000, I watched. 500, 250, 100... Hmm, nobody wants that car but me. 75, 50, 10... $1!
I parted it and made over $3,000 on those parts.
If you stick to the things nobody else wants, there is money to be made. I just bought a pair of good looking and sounding Klipsch Heresys for $5.