What is the 18 file format?
.18 is a proprietary binary data file belonging to IBM VoiceType, an early speech recognition package for Windows 3.x/95 and IBM OS/2 developed in the early 1990s. The file stores language model scripts or user-specific voice training data consumed by the VoiceType recognition engine. The numeric extension is atypical for a file format and appears to encode a language or script identifier rather than serving as a conventional file type suffix - a design choice reflecting VoiceType's internal numbering scheme.
No public specification exists for the format. IBM never published the internal layout, byte order, or data structures for .18 or the related numeric-extension files in the VoiceType suite. The files are binary, with sizes undocumented, though language data files of this era typically ranged from tens of kilobytes to a few megabytes.
IBM VoiceType was discontinued decades ago. No modern operating system or application supports the format. It was succeeded commercially by Dragon NaturallySpeaking (now Dragon by Nuance/Kofax) as the dominant desktop dictation product, while IBM's own speech technology evolved into the cloud-based IBM Watson Speech to Text API.
Files with this extension encountered today are effectively historical artefacts. There is no known conversion path to any modern format, no open-source parser for the binary structure, and no practical means of recovering the speech model data they contain.
Security & safety
RISK: LOWA .18 IBM VoiceType data file is a passive binary data file - it cannot execute and poses no malware risk. The only risk is wasting time trying to open it; no modern software supports this obsolete format.
Format details
in a nutshellPrograms that open 18 files
Windows1 app
IBM VoiceType (historical)
Paid IBM VoiceType is the only software that uses these files. It is discontinued; no download or support exists. These files cannot be opened with any modern program. Technical details
deep spec| Format type | Proprietary binary speech recognition language/script data |
| Encoding | Binary |
| Byte order | Likely big-endian (IBM OS/2 era convention); not publicly confirmed |
| Container | Proprietary IBM binary (no published specification) |
| Compression | Unknown; not documented |
| Encryption | Unknown; not documented |
| Extension meaning | Numeric extension likely encodes a language or script identifier, not a conventional file type |
| Platform | Windows 3.x/95/NT, IBM OS/2 |
| Associated software | IBM VoiceType (discontinued; no current version) |
| Successor products | Dragon NaturallySpeaking / Dragon by Nuance (desktop); IBM Watson Speech to Text (cloud API) |
| Modern support | None; no current application can open .18 files |
| Status | Obsolete; files are historical artefacts with no known conversion path |
| Released | Early 1990s (IBM VoiceType era) |
18 conversions
Community Q&A
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