I work as a computational linguist in the Virtual Resource Centre for Language Computing at Kerala University of Digital Sciences Innovation and Technology. I love to share what I learn and hence this blog.

I was awarded PhD by A. P. J. Abdul Kalam Technological University, Kerala for my thesis titled Linguistic challenges in Malayalam speech recognition: Analysis and solutions in October 2023. The work was carried out at College of Engineering Trivandrum under the supervision of Dr. A. R. Jayan and Dr. Rajeev Rajan.

I used to be a teacher in the field of electronics, signal processing and digital communication. I was employed as Assistant Professor at Govt. Engineering college, Sreekrishnapuram, Palakkad.

I am involved in various projects on Malayalam language computing. An attempt to analyse Malayalam text phonetically using finite state transducers can be seen here. I have had my hands wet in digital type design and open type engineering of a couple of fonts maintained by Swathanthra Malayalam Computing.

I try to engage with the world immediate to me in the possible ways to make life better for everyone around. It was a moment of pride that upon a request filed by me to the Chief Minister of Kerala, the Director of Higher Education Kerala issued a circular clarifying that there exists no regulations to insist the female teaching faculties to adhere to the dress code of saree.

In this blog I write about myself, my projects and whatever I feels like sharing with the world.

Live Dictation: Malayalam speech to text using subword tokens

The research carried out as part of my PhD was centred around the linguistic challenges in Malayalam speech recognition. One of the biggest chellenges associated with recognizing speech in morphologically complex languages is centred around how granular should be the text tokens. Classical ASR with Word tokens In the classical architecture of Automatic Speech Recognition (ASR) with word tokens, the acoustic model identifies fundamental sound units, the pronunciation lexicon maps sounds to words, and the language model predicts word sequences to convert speech to text. [Read More]

An Open Framework to Build Malayalam Speech to Text System

It was indeed a pleasure to present my paper on An openframework to develop Malayalam Speech to text Systems at the 35th Kerala Science congress held during 10th-14th of February, 2023 at Kuttikkanam, Kerala India. The work was presented in the category of Scientific Social Responsibility and recieved the best oral presentation award in that category. The presentation was all about how I ensured openness and transperancy in the development process of speech recognition system for Malayalam done as part of my PhD work Linguistic Challenges in Malayalam Speech Recognition: Analysis and Solutions. [Read More]

How to create a Malayalam Pronuciation Dictionary?

What is a phonetic lexicon? A pronunciation dictionary or a phonetic lexicon is a list of words and their pronunciation described as a sequence of phonemes. It is an essential component in the training and decoding of speech to text (STT) and text to speech (TTS) systems. A pronunciation dictionary is slightly different from a simple phonetic transcription. It should contain delimiters between phonemes, space is usually the default choice. [Read More]

Mlphon: A Multifunctional Grapheme-Phoneme Conversion Tool Using Finite State Transducers

The Mlphon tool I had been working on, for the past couple of years was extensively expanded as part of my research work at College of Engineering Trivandrum. A detailed presentation of the phonemic features of Malayalam, their incorporation as a sequential ruleset in the form of finite state transucers, a quantitative evaluation of the applications of the tool are now available in the article, published by the open access journal, IEEE Access. [Read More]

മനുഷ്യഭാഷ, യന്ത്രബുദ്ധി

ശാസ്ത്രഗതി (ജൂൺ 2022) പ്രസിദ്ധീകരിച്ച ലേഖനം ആമുഖം മനുഷ്യർക്കു നൈസർഗ്ഗികമായുള ഒരു കഴിവാണ് ഭാഷ. കുഞ്ഞുങ്ങൾ ഏതു ഭാഷയും അവരുടെ പരിസരങ്ങളിൽ നിന്നും സ്വാഭാവികമായി നേടിയെടുക്കുന്നു. ഈ ശേഷി ഒരു കമ്പ്യൂട്ടറിന് കൈവരിക്കാൻ അത്ര എളുപ്പമല്ല. സിനിമാടിക്കറ്റ് ബുക്ക് ചെയ്യാനും, ഭക്ഷണം ഓർഡർ ചെയ്യാനും, മെയിലയക്കാനും, അലാറം വെയ്ക്കാനുമൊക്കെ ഇംഗ്ലീഷ് ഭാഷയിൽ പറഞ്ഞാൽ ചെയ്യാൻ കഴിയുന്ന ഡിജിറ്റൽ അസിസ്റ്റന്റുകളൊക്കെ ഇന്നുണ്ട്. ഇതിനർത്ഥം യന്ത്രങ്ങൾ ഭാഷാശേഷി കൈവരിച്ചുവെന്നാണോ? മലയാളമുൾപ്പെടെയുള്ള മറ്റു ഭാഷകളും കമ്പ്യൂട്ടറുകൾക്കു വഴങ്ങുമോ? അതിനു കൃത്രിമബുദ്ധി ആവശ്യമുണ്ടോ? ഈ വിഷയങ്ങളൊക്കെ പരിശോധിക്കുകയാണ് ഈ ലേഖനത്തിൽ. യന്ത്രങ്ങൾക്ക് സ്വയം പഠിക്കാനാകുമോ? ചുറ്റുപാടുമുള്ള ശബ്ദങ്ങൾ പിടിച്ചെടുക്കാനുള്ള ഉപകരണം എല്ലാ ഫോണുകളിലുമുണ്ട്. ആ ശബ്ദത്തിൽ നിന്നും സംസാരം വേർതിരിച്ച്, പറഞ്ഞതെന്തെന്ന് തിരിച്ചറിയാനുള്ള സംവിധാനം പല ഭാഷകളിലും ഇന്ന് സാധ്യമാണ്. [Read More]

Mozhi Malayalam TTS powered by Mlphon and Mlmorph

Krishna Sankar recently developed a Malayalam - English bilingual Text to Speech System, Mozhi. Check the web demo page and play around with your choice of words and listen to the natural speech it produces. Krishna has set a future goal of understanding the emotional content of the text and read it out accordingly. This is expected to make the application suitable for audio books. Generating audio for arbitrary speaker with very few training samples is another area he plans to work on. [Read More]

Publishing Malayalam Speech Recognition Model

Malayalam speech recognition model trained on various openly available speech and text corpora using Kaldi toolkit is now released here. It is now available for testing on the Vosk-Browser Speech Recognition Demo website. This Malayalam model can be used with Vosk speech recognition toolkit which has bindings for Java, Javascript, C# and Python. A speech recognition architecture that works best in scenarios of limited speech data availability is called a pipeline model, where it is composed of an acoustic model, a language model and a phonetic lexicon. [Read More]

The language of infinite words

I wrote this article for submission to a popular science writing competition by the Department of Science and Technology. Here is my research story, which did not make to grab the award. The story is based on our research on the morphological richness of Malayalam language. How many words are there in your language? How many of them do you know? Can you find all those words in a dictionary? [Read More]

Text Speech and Dialogue: TSD 2020

I presented a paper on Quantitative Analysis of the Morphological Complexity of Malayalam Language at 23rd International Conference on Text, Speech and Dialogue: TSD 2020, Brno, Czech Republic, September 8–11 2020. The year being 2020, the entire conference happened in remote participation mode. Conference proceedings and pre-recorded presentation videos were made available to the participants and we discussed it over online zoom sessions. It was a novel experience and I am super excited about how I got feedbacks and ideas to work on, even after the live sessions. [Read More]

A quantitative analysis of the morphological complexity of Malayalam

My work, Quantitative Analysis of the Morphological Complexity of Malayalam Language is accepted for presentation at the 23rd International Conference on Text, Speech and Dialogue to be held from September 8-10, 2020. The conference proceedings is published by Springer and you can read the paper here. I will share the presentation slides and video after the conference. See the associated data and code here. This blog-post is a bit detailed discussion of the following aspects, analysed in the paper: [Read More]