There area unit many dialects within the Bengali-speaking region. Not all of those area unit reciprocally intelligible; so, some, like Sylheti, area unit quite completely different from the remainder. These kind a time from east to west. owing to historical prominence of town of metropolis because the base of the Empire and therefore the Bengali Renaissance, the 2 official registers of normal Bengali (one in Republic of India, one in Bangladesh) area unit each primarily based roughly on the non-standard speech spoken within the Kolkata-Nadia region.

I am scarcely at home with all the acoustics word, and can greatly appreciate edits therein regard, however these area unit some that come back to mind:

Eastern dialects place less stress on several syllables. ‘ch’ becomes ‘s’, ‘kh’ becomes ‘x’. and lots of a lot of.
Eastern dialects exhibit bigger pitch variation on the average. Not the maximum amount because the conventional dhakaiya in Indian Bengali movies and tropes, however its there.

Because there area unit fewer huge cities in Bangla Desh and Assam, japanese dialects tend to be connotated as ‘rustic’. Kindof like however a Home County man would treat a Mancunian or a Yorkie. There has been some discrimination supported this within the past, and even these days.
Eastern dialects tend to pronounce the 3 s’s (স,শ,ষ) during a} very similar manner. In western dialects the distinction is a lot of marked.
Word endings, as Ratul Saha mentioned. particularly the endings of verbs. The curt ‘-e’ endings of Western dialects transition into ‘-iya’ or ‘-o’ in japanese dialects.

There area unit refined variations within the language employed by Hindus and Muslims throughout the whole region. Muslims, or individuals from Muslim families, tend to use a lot of Arabic-Persian-Turkish loan-words.

To make a comparison with alternative japanese Indic languages, i might say that a verbalizer of Oriya would, for instance, perceive Western Bengali dialects higher, whereas a verbalizer of Assamese would perceive japanese Bengali dialects higher.

Some words used area unit different; nun (নুন) vs lobon (লবন) for salt, for instance. There area unit more however none presently come back to mind.
Ultimately one should detain mind that from the point of view of linguistics it doesn’t build a lot of sense to be nitpicky concerning what precisely constitutes a language, or wherever one language begins and another ends. The division of the geographic area region post 1905 was primarily based a lot of on spiritual than on linguistic grounds. Also: West Bengal is not the solely ‘Indian Bengali’ region in Republic of India. Bengali is an officer language in 3 alternative states: Assam, Tripura, and Jharkhand, and within the union territory of Andaman and Nicobar Islands; all of that have an outsized Bengali-speaking population.