ESPS Sampled Data
|Entropic Research Laboratories
3.5 | 40 Votes
What is an SD file?
An SD file is an audio file used by the WAVES+ display program, ESPS signal processing library, and the Hidden Markov Model Toolkit. It is saved in a proprietary format created by Entropic Research Laboratories. SD files may also be referred to as .ESPS files.
Entropic Research Laboratories was a software company that specialized in creating software used to analyze and manipulate human speech signals. These programs included WAVES+, ESPS, and the Hidden Markov Model Toolkit (HTK).
All the above programs used audio files saved in proprietary file formats developed by Entropic Research Laboratories. SD files contain samples of human speech saved in the ESPS (Entropic Signal Processing System) format. This format was later replaced by Entropic's Esignal format.
NOTE: Microsoft purchased Entropic in 1999. As a result, Waves+ and ESPS were discontinued. However, Cambridge University continues to maintain and distribute the Hidden Markov Model Toolkit.
How to open an SD file
You can use the Hidden Markov Model Toolkit (multiplatform), FMJ-Software Awave Studio (Windows), or Festival (Linux) to play the speech an SD file contains.
Programs that open SD files
Sound Designer Audio File
2.8 | 13 Votes
Audio format used by Sound Designer, one of the first popular audio-editing programs available for the Mac