Rukmani says that the new townspeople, who "travelled more than a hundred miles to get (to the village)...spoke in our language, but with an intonation which made it difficult for us to understand them" (Chapter 4).
An intonation is a variation in pitch, rather than in pronunciation. The townspeople of which Rukmani speaks pronounced the words they spoke in the same manner as the villagers, but their pitch, or tone, in conversation was different. A difference in intonation can be illustrated by comparing the way the voice goes up at the end of a question such as "Where are you going?", to the way the voice goes down at the end of a statement such as "I am going to the store". The different intonation utilized by the new townspeople who came to Rukmani's village was apparently marked enough so that to the villagers, they were hard to understand.