If you played more than one game at a time it would sound crazy, which can make it a little more entertaining. Some of the sound overlaps give the individual sounds a unique perspective. Regular players of the game have come to expect the sounds to perform a certain way. If you turn off the sound, you can still imagine what they say. There is a close association between the appearance of the card and the sound it makes. This is how we learn about the animals in the wild and on farms.
I think it can be a fun challenge to play a couple games at the same time. nate Silver talked about playing 4 and 5 games of Blackjack on the internet when gambling was unregulated. He made a lot of money by increasing his productivity. But it takes a keen sense of focus to stay in tune with all the games for any length of time:
This is an interesting article: