**And the reason/significance of doing that is..............
this azaan and iqaama at ones birth time is meant for the Nimaz-i-Janaza.....................at the end of life!
In the Masjid for regular prayers Azaan is said and then just before the Nimaz starts the Iqaama is said...........there is a very short time period delay..........actually soon after the iqaama is said the Nimaz starts..........
Hence this short duration between the end of iqaama and the start of Nimaz signifies the short time we are on Earth..................
**
indeed..sometimes too short.