Islamic prayer times are determined by the position of the sun.
Fajr is determined at the first light of dawn so the call to prayer will vary according to the time of year.
Today, in London it is 5:32 a.m.
In New York, the sun rises between approximately 5:25 a.m. and 7:15 a.m. depending on the season.
These are busy, noisy cities that rarely sleep anyway. People are up early for work. I worked in London for 50 years and rose at 5:30am, showered, breakfasted, walked to the station to be on a train by 7:00 latest to be in work for 8:00am. It was no big deal.
Wherever one lives, there will be early morning noise; whether it's a cock crowing, a motor-biking neighbour going to work, general traffic, living by a busy railway line etc etc. Night workers are used to sleeping in the day through the usual hubbub of daytime noise. It’s what earplugs were made for.