HTK File

What are HTK files and how to open them

Are you having problems opening a HTK file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your HTK files.

What is a HTK file?

A .HTK file is a Hidden Markov Model Toolkit Audio file.

Hidden Markov Model Toolkit Audio File (extension .htk) is a file produced by the Hidden Markov Model Toolkit (HTK), a speech-recognition research toolkit developed by Cambridge University. It is used to store audio data or derived acoustic features (such as cepstral coefficients or filter-bank outputs) in a binary form optimized for HTK's training, recognition, and signal analysis modules.

Files in this format are created by HTK tools when converting standard waveforms or when extracting parameters from speech for modelling. Once generated, these .htk files feed HTK's algorithms that build, test, or evaluate Hidden Markov Models. They are not intended for playback by regular media players unless converted.

Every .htk file begins with a 12-byte header containing: a 4-byte integer for the number of samples (or frames), a 4-byte integer for sample period in units of 100 ns, a 2-byte integer for the number of bytes per sample or frame ("sampSize"), and a 2-byte integer "parmKind" code that specifies the type of data stored (example kinds include waveform, LPC, MFCC etc.) and any qualifiers (such as including delta or acceleration coefficients).

How to open HTK files

We have identified one HTK opener that is compatible with this specific type of HTK file.

Programs that open Hidden Markov Model Toolkit Audio files

Last updated: August 7, 2026

Various apps that use files with this extension

These apps are known to open certain types of HTK files. Remember, different programs may use HTK files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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