Back then cities were more dense and, as well, individual households were more dense. It is possible, maybe even likely, that those pockets would measure louder than anything we're accustomed to today. But, at the same time, you would also have more places completely free of human activity to balance that out and then some when computing an average.
People had a lot more kids and those kids were around all the time. Just cry from babies and toddlers must have been around much more then today - today you barely ever hear it and many adults are unable to handle hearing it.
Back then cities were more dense and, as well, individual households were more dense. It is possible, maybe even likely, that those pockets would measure louder than anything we're accustomed to today. But, at the same time, you would also have more places completely free of human activity to balance that out and then some when computing an average.