I think it's only to increase the sound of the horn to be able to here it in the loud traffic noise also.
There are many websites where one can find the price of a Citroen DS3. One can find prices of a Citroen DS3 on the "Carwow" website, as well as on the "What Car?" website.
To replace the horn on a Citroën DS3, first, disconnect the vehicle's battery to ensure safety. Remove the front grille or access panel to locate the horn, which is usually mounted near the front of the vehicle. Disconnect the electrical connector and unbolt the horn from its bracket, then install the new horn by reversing the process—mounting it securely and reconnecting the electrical connector. Finally, reconnect the battery and test the new horn to ensure it functions properly.
DS3 is 44.7 Mbps and a T1 is 1.55 Mbps. So 1 DS3 = 28 T1s http://www.dslbroker.com/ds3.html
A DS3 has 28 T1's http://techblog.intelletrace.com/what-is-a-ds3-hub/
3 ds3 in stm1
A DS3 can do 45Mbps Bidirectional Simultaneously.
how many DS3's are in an OC192
I invented the car horn
an OC48 has 48 DS3's.
672 DS0 make 1 DS3
What is the decibel level of a car horn?
Push the car horn button....