What is speech to text?

by Stephen M. Walker II, Co-Founder / CEO

What is speech to text (STT)?

Speech to Text (STT), also known as speech recognition or computer speech recognition, is a technology that enables the recognition and translation of spoken language into written text. This process is achieved through computational linguistics and machine learning models.

STT works by listening to audio and delivering an editable, verbatim transcript on a given device. The software uses voice recognition to sort auditory signals from spoken words and transfer those signals into text using characters called Unicode. When users speak clearly, script accuracy rates can exceed 95%.

There are two main types of STT: speaker-dependent, which is mostly used for dictation software, and speaker-independent, which is used for phone applications. The transcribed text can be utilized by applications, tools, and devices as command input, making STT a valuable tool for professionals in various fields in need of high-quality transcriptions.

STT technology has evolved significantly over the years, with advances making transcription faster, cheaper, and more convenient than manual transcription. It's also an important tool for equal access and digital accessibility, allowing users with disabilities to type on and operate computers.

STT is used in a variety of applications, including voice typing apps, transcription services, and AI chatbots. It can also be used to transcribe phone calls in call centers to identify common call patterns and issues.

IBM Watson Speech to Text is an example of a cloud-native solution that uses deep-learning AI algorithms to apply knowledge about grammar, language structure, and audio/voice signal composition to create customizable speech recognition for optimal text transcription.

How does speech-to-text technology work?

Speech-to-text (STT) technology, powered by computational linguistics and machine learning models, translates spoken language into written text. The process begins with sound capture, where the software records the vibrations produced by speech. This sound is then digitized using a Fast Fourier Transform algorithm, converting the sound graph into a spectrogram. The digitized sound undergoes feature extraction, identifying elements like frequency, intensity, and duration. Linguistic algorithms then recognize and convert these auditory signals into text using Unicode characters. Finally, the text is presented based on the most probable interpretation of the audio.

STT technology comes in two main types: speaker-dependent, primarily used for dictation software, and speaker-independent, often used for phone applications. Modern STT technologies employ deep learning to create a single, end-to-end model that is both accurate and fast. These models can handle speech recognition in diverse environments and can even identify the speaker.

STT technology finds applications in various fields, from everyday use on phones to industries like marketing, banking, and medical. It's also used in customer service, electronic documentation, and for accessibility purposes. Despite its advancements, STT technology still faces challenges, such as lower accuracy compared to human transcription and the need for technical expertise to get started. However, continuous research and development in the field promise further improvements.

What are some common applications of speech-to-text technology?

Speech-to-text (STT) technology is a versatile tool with applications spanning various industries. It powers voice search, enabling users to verbally express their queries to digital assistants like Alexa, Cortana, Google Assistant, and Siri. In smart homes, STT technology translates voice commands into actions, controlling devices such as lights, thermostats, and more.

In the healthcare sector, STT technology transcribes doctors' notes during patient examinations, freeing doctors to focus on the patient. It also enhances navigation systems by allowing drivers to issue voice commands to vehicle devices, promoting safer driving.

Customer support call centers leverage STT systems to automate customer interactions, freeing human agents to handle complex issues. For individuals with disabilities, STT processing enhances accessibility, enabling control of devices through voice commands.

Workplace productivity is boosted by STT technology through transcription of emails, documents, and meeting minutes. It also powers translation applications like Google Translate, providing translations in over 100 languages from spoken input.

Voice command and dictation systems, common in social media platforms and the healthcare industry, rely on STT technology. For instance, doctors can dictate voice notes filled with medical terminology, and the accurate text output can be added to a patient's electronic medical record. Some companies are even exploring voice recognition for payment transactions, offering a convenient method for shopping from smartphones or computers.

What are some popular speech-to-text software programs?

The evolution of speech-to-text technology has led to the development of numerous software programs, each with unique features and capabilities. Among the most popular ones are:

Dragon by Nuance, renowned for its high accuracy and customization options, offers Dragon Anywhere for mobile devices and Dragon Professional for desktops. Google Docs Voice Typing is a free feature within Google Docs that enables users to dictate text directly into a document. Windows Speech Recognition, a built-in feature in Windows 11, is effective for dictation in any installed app, particularly Microsoft Word, which also offers file transcription.

Apple Dictation is a free software available on Apple devices, known for its accuracy and real-time speech detection. Gboard, a free mobile dictation app developed by Google, is integrated with Google Assistant for enhanced functionality. Otter is designed for collaboration, making it ideal for transcribing meetings or group discussions.

Braina Pro is a speech recognition software that works with text, video, and photo apps, providing multiple options for users. Transcribe - Speech to Text is recommended for iPhone, iPad, and Mac users, offering transcription services for both live recording and saved audio files.

For enterprise use, Microsoft Azure's Speech-to-Text Services and Amazon Transcribe offer high accuracy through a combination of dictation software, AI, and human proofreaders.

The effectiveness of these tools can vary based on factors like the speaker's accent, the clarity of the speech, and the background noise. Therefore, it's important to choose a software that best suits your specific needs and environment.

What are some limitations of speech-to-text technology?

While Speech-to-Text (STT) technology offers numerous benefits, it's important to be aware of its limitations. The accuracy of STT can be affected by factors such as multiple speakers, language variability, and the speed of speech. Misinterpretations or mishearing of words can occur, especially when the technology struggles to distinguish between different voices or keep up with the average speaking speed of 110 to 150 words per minute.

The performance of STT can also be impacted by background noise, accents, pronunciation, grammar, punctuation, or formatting. It may require training to recognize specific voices and learn specific commands and keywords. Furthermore, the variability of language, vocabulary, accents, and sound quality can pose challenges for error-free usage of STT.

Cost is another consideration as most STT tools require a subscription or upgrade to access the full range of features. This can add up quickly, especially for regular users. Additionally, there can be a learning curve for new users to effectively use STT tools.

Lastly, integration and customization can be problematic with some STT solutions. They may not easily integrate with existing systems or offer many customization options, which can be particularly challenging in specific industries like healthcare.

Despite these limitations, STT technology continues to evolve and improve, often making its benefits outweigh the challenges for many users.

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