The two states- A note on the difference in religious practices

Kerala and Tamil Nadu are the two south indian states which though they share quite a long border are so different from each other.. In fact in every aspect! be it food, culture, attitude of the people, ethics, ideologies, economics, terrain... the list is endless. But this is more or less true between almost every other state.
Something that reminded me of this distinction was a string of events that happened in my neighborhood. Its Diwali so in my house we had organized a pooja of sorts for the auspiciousness of our home and we had this kerala brahmin poojari called a nambhoodhiri who came to do the pooja. He insisted on several things to be readied before he was to begin the yajnam  my dad and I ensure all that was done and that we were all supposed to have finished our morning chores by 5 the next morning. the pooja commenced and the nambhoodhiri whisper chanted mantras igniting a fire and sacrificing ghee,flowers etc. into the fire. A sense of discipline and serenity is brought into the atmosphere and the whisperings of the nambhoodhiri disturbing the smoke around him a little bit. He gives you a sort of feeling that he is talking to the fire and addressing the Gods. Its an amazing thought.
The pooja now being held in our neighbors house on the other hand is purely tamil nadu culture. The initial preparation is the same however the house echoes of veda chants uttered by the swamiyaars. So much that I can hear it all the way on my way back home from their house and could still hear it from my room!
Its really nice to analyze what methods of performing yajnams have been passed down in each of the cultures, one involving inaudible murmuring of mantras as though talking to the smoke and fire, another with mantras being chanted out aloud so its goodness can be heard all around in the home. I perceive it as  the namboodhiris through their veda chanting communicate with the divine powers through fire and sacrifice oblations to receive blessings. The smoke from the yajna I believe carries around the goodness to every corner of the house.  The Tamil nadu religious culture possibly believes that the vedas themselves are powerful enough hymns that which by chanting, blessings maybe sought from the divine beings hence they are chanted out loud by the swamiyaars so its vibrations reach all the corners of the home bringing goodness. A lot of swamiyaars together chant the mantras for a stronger vibration which aids the purpose.
So profound is the cultural diversity in India is. and this is inspite the fact that the mantras chanted in either yajnas are more or less the same- The Vedas.