First proposed in Sameer ud Dowla Khan's 2008 dissertation, Bengali Tones and Break Indices (B-ToBI) is a phonological model and annotation system for the intonation of Bangladeshi Bengali. The model is part of a tradition of prosodic research known as the Autosegmental-Metrical (AM) Model of Intonational Phonology, which has produced intonational models of a wide diversity of languages. Many of these models have ToBI in their name, based on the prosodic annotation system they use.

The most recent publication describing the B-ToBI model is a 2014 chapter of Sun-Ah Jun's Prosodic Typology II, but this website will be updated as the model continues to grow and evolve. This version was last updated on 29 February 2016.


B-ToBI is the name for both a phonological model of Bangladeshi Bengali intonation and the annotation system used to represent analyzed recordings of speech. This website attempts to describe both the model and the annotation system simultaneously. Each tonal element is illustrated in an example sound file along with an image of its pitch contour in blue. Below the pitch contour are three transcription tiers:

  • The tones tier shows the tonal events, e.g. L*, Ha
  • The words tier shows segmentation and transcription of the text, e.g. calokTa
  • The English tier shows English labels for words and suffixes, e.g. 'tea', 'man-DEF'

Below the image of the pitch contour and tiers, a link to the sound file is found on the [recording code], along with a repetition of the words tier transcription and a 'loose English translation' of the utterance.


[A19] eI lokTa amar gaEer upor ca Dhallo. 'This man spilled tea on me.'

About the recordings

The recordings included here were all produced by native speakers of Bengali who grew up in Bangladesh (or in a few cases, in India) and later moved to the US or were visiting the US at the time of recording. Recordings were made in the participants' homes in Southern California, between 2006-2007. Most recordings here were made from a prepared script, designed to minimize the appearance of obstruents (which interrupt the tracking of pitch). Recordings with an "S" ("spontaneous") in the middle of the identification code were unscripted; these were collected from speakers "reading" from Frog, Where Are You?, an illustrated children's book with no text.

While the B-ToBI model is primarily based on Bangladeshi Standard Bengali (as spoken by Bangladeshi Americans), it can reasonably be extended to Indian Standard Bengali and nonstandard regional varieties of Bengali. (With adjustments to allow for lexical pitch accent contrasts, it could presumably be extended to Sylheti, Chittagonian, Chakma, Arkani/Rohingya, etc.) Indeed, some participants used their native regional varieties in the unscripted recordings, and these are incorporated into the B-ToBI model.


Selected publications that adopt the B-ToBI model for describing Bengali intonation are listed below:

Khan, SD (2014). The intonational phonology of Bangladeshi Standard Bengali. In Sun-Ah Jun (ed.). Prosodic Typology II: the Phonology of Intonation and Phrasing. OUP. (sound files)

Yu, Kristine M., SD Khan, and Megha Sundara (2014). Intonational phonology in Bengali and English infant-directed speechProceedings of Speech Prosody 7. Dublin: Trinity College.

Hsu, Brian (2014). Variation in Bangla complementizer order at the syntax-prosody interface. 45th Annual Meeting of the North East Linguistic Society: MIT.


B-ToBI builds on the work of many linguists around the world, many of whom work in different frameworks. I've included links to just a handful of reearchers (in alphabetical order) who study Bengali intonation, some of whom work directly with B-ToBI and some of whom work(ed) on previous models or alternative models of Bengali intonation:

  • Tanmoy Bhattacharya (U Delhi): proposes an information-structural model of Bengali intonation in 2008
  • Arunima Choudhury (USC): specializes in focus prosody in both Bengali and Hindi
  • Shyamal Das (Tripura U): 2001 dissertation describes Tripuri and Kolkata Bengali stress assignment
  • Jennifer Fitpatrick-Cole (U Konstanz): co-authored a 1999 paper on emphatic particles with Aditi Lahiri
  • Bruce Hayes (UCLA): co-authored "Bengali intonational phonology" in 1991 with Lahiri
  • Brian Hsu (USC): uses B-ToBI to investigate the prosodic factors in complementizer order variation
  • Sameer ud Dowla Khan (Reed): developed the B-ToBI model and is co-authoring a description of infant-directed intonation with Yu and Sundara
  • Aditi Lahiri (Oxford): co-authored "Bengali intonational phonology" in 1991 with Hayes and a 1999 paper on emphatic particles with Fitzpatrick-Cole
  • Elisabeth Selkirk (U Mass Amherst): proposes a prosodic model in 2006 with data from Hayes & Lahiri
  • Megha Sundara (UCLA): currently co-authoring a B-ToBI description of infant-directed intonation with Yu and Khan
  • Hubert Truckenbrodt (ZAS Berlin): 2002 paper provides an OT syntactic account of phrasing with data from Hayes & Lahiri
  • Rashad Ullah (Yale): currently using B-ToBI to investigate the focus realization of NPIs and related phenomena in Bengali
  • Kristine Yu (U Mass Amherst): currently co-authoring a B-ToBI description of infant-directed intonation with Khan and Sundara

I've also included links to researchers who study the intonation of other languages spoken in and around the region of Bengal, including Assamese, Sylheti, and Boro:

  • Kalyan Das (IIT Guwahati): first instrumental analysis of lexical tone in Boro
  • Amalesh Gope (IIT Guwahati): first instrumental analysis of lexical tone in Sylheti, co-authored with Mahanta in 2014
  • Shakuntala Mahanta (IIT Guwahati): first instrumental analysis of lexical tone in Sylheti, co-authored with Gope in 2014; also an intonational phonological model of focus prosody in Assamese, co-authored with Twaha in 2015
  • Asimul Islam Twaha (IIT Guwahati): intonational phonological model of focus prosody in Assamese, co-authored with Mahanta in 2015