Digital Dictation

Digital dictation is a method of recording and editing the spoken word in real-time. The recording is done by the use of a digital recorder. Digital recorders are lighter have a longer battery life and are able to record a for a lot longer utilizing the same media, as compared to analog tape based dictation machines. The files generated with digital recorders vary in size(kilo bites or mega bites) depending on the manufacturer and the format the user chooses. The most common file formats that digital recorders generate have following extension WAV, WMA, and MP3 true dictation machines record in the DSS and DS2 format.

The DSS and DS2 file formats compress audio allowing for greater portability. In some cases speech is recorded where sound quality is paramount and transcription unnecessary, e.g., for broadcasting a theatre play; such recording uses techniques closer to high-fidelity music recording, rather than those discussed here.

Digital dictation offers several advantages over traditional cassette tape based dictation:

• The user can instantly rewind or fast forward to any point within the dictation file to review or edit.
• The random access ability of digital audio allows inserting audio at any point without overwriting the following text.
• Dictation produces a file which can be transferred electronically, e.g. via WAN, LAN, USB, e-mail, telephony, BlackBerry, FTP, etc.
• Large dictation files can be shared with multiple typists.
• Sound may be CD quality and can improve transcription accuracy and speed.
• Digital dictation provides the ability to report on the volume or type of dictation and transcription outstanding or completed within an organization.

Dictation audio can be recorded in various audio file formats. Most digital dictation systems use a lossy form of audio compression based on modelling of the vocal tract to minimize hard disk space and optimize network utilization as files are transferred between users. (Note that WAV is not an audio encoding format but a file format and has little or no bearing on the encoding rate (kbit/s), size or audio quality of the resulting file.)

Digital dictation is different from Speech Recognition where audio is analyzed by a computer using speech algorithms in an attempt to transcribe the document. With digital dictation the process of converting digital audio to text may be done using a digital transcription software, typically controlled by a foot switch which allows the transcriber to PLAY, STOP, REWIND, and BACKSPACE.