Abstract
Speech-to-text (STT) conversion, also known as automatic speech recognition (ASR), refers to the
process of converting spoken language into written text. This technology has gained significant
attention in recent years due to its potential applications across various domains, including
healthcare, customer service, education, and accessibility. The primary goal of STT systems is to
accurately transcribe human speech in real-time or from recorded audio data while handling
variations in accents, speech patterns, background noise, and other real-world challenges.
The STT conversion process typically involves several stages, including audio signal
preprocessing, feature extraction, pattern recognition, and text generation. Initially, the input audio
is captured using microphones or recording devices, followed by the extraction of relevant features
such as Mel-frequency cepstral coefficients (MFCCs) to represent the speech signal. These
features are then processed using machine learning algorithms—ranging from traditional hidden
Markov models (HMMs) to more advanced deep learning models such as convolutional neural
networks (CNNs) and recurrent neural networks (RNNs), including Long Short-Term Memory
(LSTM) networks. These models are trained on large datasets to recognize and predict phonetic,
linguistic, and contextual elements of speech.
Key challenges faced by speech-to-text systems include handling homophones, speech
disfluencies, speaker variability, noise interference, and real-time processing demands. To improve
accuracy and robustness, STT systems often incorporate techniques such as noise filtering, speaker
adaptation, language modeling, and context-based corrections.