speech recognition (ASR)
in English: speech recognition / speech-to-text
Speech recognition is a technology that automatically converts spoken human language into written text, allowing the machine to "transcribe" what you say.
In plain terms
Imagine a tireless stenographer who types out everything they hear, whether dictation, a phone call, a lecture, or a video. Speech recognition does the same as software: sound goes in, text comes out.
It serves to make spoken words searchable, editable, and shareable. This becomes the automatic subtitles for videos, the transcript of meetings, and the voice-dictated message on the phone. It is often the first step even when you are conversing with an AI assistant via voice.
It is important that speech recognition only transcribes, it does not interpret. What the transcribed sentence means and what to do with it is decided by another system, such as a language model or an AI agent. Some newer, so-called multimodal models can process sound directly without transcription, but this is already more than just speech recognition.
How it works
- The microphone converts sound into a digital signal, and the software breaks it into short slices of a few hundredths of a second.
- For every slice, it calculates how strongly high and low vibrations resonate within it. From this, a visual fingerprint of the sound is created, showing how the sound changes over time (called a spectrogram).
- A neural network trained on a vast number of hours of transcribed audio recordings estimates which sounds, syllables, and words the audio samples correspond to.
- The model also considers the context: among similarly sounding options, it chooses the one most likely in that specific sentence.
- Modern systems add punctuation and capitalization to text, often include timestamps, and some solutions also indicate who is speaking.
An everyday example
You are rushing for the bus with no hand free to type, so you press the microphone button on your phone and dictate: "I will be ten minutes late, start without me." The phone transcribes the sentence, and you send it with one tap.
Who is affected
A common misconception
Limits and risks
- Accuracy noticeably declines in noise, with poor microphones, when speakers interrupt each other, with strong dialects, or with technical jargon.
- Names, numbers, abbreviations and foreign words are the most common sources of error, so always read through a text (a contract, a medical report, a quotation) carefully.
- Some models may insert text in quiet or noisy sections that was never spoken.
- Your voice is personal data: check whether the recording stays on your device or goes to a company server, and record others' speech only with their knowledge.
Similar, but not the same
- speech synthesis – Speech synthesis works in the opposite direction: it generates machine voice from written text, while speech recognition creates text from voice.
- speaker recognition – Speaker recognition determines who is speaking, while speech recognition determines what is being said.
- natural language understanding – Language understanding interprets the meaning and intent of already written text, while speech recognition only reaches the transcription stage.
Related concepts
artificial intelligence, Natural language processing, machine learning
dictation, automatic captioning, voice control, speaker diarization
speech synthesis, voice assistant, voice cloning, multimodal model, machine translation
A brief history
The first known speech recognizer was the machine named Audrey, introduced by Bell Labs in 1952, which recognized spoken digits from a single speaker. OpenAI released the open-source Whisper model in 2022, which made usable accuracy widely available in many languages, including Hungarian.
Where things stand
At the end of 2026, speech recognition is a basic feature of phones, video-calling software, and AI assistants, and it works well in Hungarian too. Development is moving toward real-time voice conversation, multimodal models that process audio directly, and models that run on the device without an internet connection.
In the news
- Multilingual medical speech recognition: Oak and other AI toolsOct 13, 2026 · Health
- Hungarian Bar Association issues position on lawyers' use of AI speech-to-text toolsAug 10, 2026 · Jog
- CLIVORA project develops Hungarian-language AI medical speech recognition and report generationAug 3, 2026 · Health
Also known as
speech recognition · Automatic speech recognition · speech-to-text conversion · speech recognition · speech recognition · speech-to-text · STT · ASR
Sources
- Wikipedia: Speech recognition
- Radford et al.: Robust Speech Recognition via Large-Scale Weak Supervision (the Whisper paper, 2022)
This entry was machine-edited and has undergone machine expert review; the “In the news” section updates automatically from Agent Age stories.