Apart from the Mighty Sound Effects Lady on One Away, are the sound effects on the show actually controlled by humans, or are they automated (like “programmed” into the games)?
During the Barker years, the sound effects were always activated by a person trying to play the sound effect at the same moment a number appeared or a flap opened.
Now that the pricing games are controlled by one computer, when sound effects can be built in, they are. For example, when Double Cross is lost, the computer is programmed to play the buzzer at the same time the board turns red. Or play the bells at the same time the winning animation is activated.
But there are a lot of moments on the show that aren't computer controlled. For example, in Temptation, a number appearing in the contestant's bid can be tied to a bell, but the panels that drop to reveal the actual price aren't connected to anything electronic, so those bells/buzzers have to be sounded the old-fashioned way (or rather, in the style of the old-fashioned way by clicking a button in the computer program to simply play a bell or buzzer sound). When somebody reveals a price in Most Expensive or One Wrong Price, the accompanying ding or buzz has to be manually sounded (but I wouldn't be surprised if the multiple bells that sound on a win are tied to the activation of the flashing lights). And games like Money Game and Double Prices don't have any electronic components whatsoever.