Modern Translation Systems heavily rely on high-quality, large parallel datasets for state-of-the-art performance. However, such resources are largely unavailable for most of the South Asian languages. Among them, Nepali and Tamang fall into such category, with Tamang being among the least digitally resourced languages in the region. This work addresses the gap by developing NepTam20K, a 20K gold standard parallel corpus, and NepTam80K, an 80K synthetic Nepali–Tamang parallel corpus, both sentence-aligned and designed to support machine translation. The datasets were created through a pipeline involving data scraping from Nepali news and online sources, pre-processing, semantic filtering, balancing for tense and polarity (in NepTam20K dataset), expert translation into Tamang by native speakers of the language, and verification by an expert Tamang linguist. The dataset covers five domains: Agriculture, Health, Education and Technology, Culture, and General Communication. To evaluate the dataset, baseline machine translation experiments were carried out using various multilingual pre-trained models:mBART, M2M-100, NLLB-200, and a vanilla Transformer model. The fine-tuning on the NLLB-200 achieved the highest sacreBLEU scores of 40.92 (Nepali → Tamang) and 45.26 (Tamang → Nepali).

The Automatic Speech Recognition (ASR) has come up with significant advancements over the course of several decades, transitioning from a rule-based method to a statistical approach, and ultimately to the use of end-to-end (E2E) frameworks. This phenomenon continues with the progression of machine learning and deep learning methodologies. The E2E approach for ASR has demonstrated predominant success in the case of resourceful languages with larger annotated corpus. However, the accuracy is quite low for low-resourced languages such as Nepali. In this regard, language-specific tools such as tokenizers seem to play a vital role in improving the performance of the E2E model for low-resourced languages like Nepali. In this paper, we propose a pronunciationaware syllable tokenizer for the Nepali language which improves the results of the E2E model. Our experiment confirm that the introduction of the proposed tokenizer yields better performance with the Character Error Rate (CER) 8.09% compared to other language-independent tokenizers.