Custom vocabulary

Custom vocabulary is a list of words, names and phrases that you add to a dictation tool so it recognizes and spells them correctly. Each entry usually pairs the written form with a spoken form, which is how you say the word aloud. Vendors call the same feature a custom dictionary, a word list or a vocabulary editor, and the names vary from product to product.

Without an entry, a recognizer picks the closest word it knows. Say your company is called Brindlemoor and a colleague is called Ilse Ferreira. A recognizer that has never seen those names may type "Brindle moor" and "Ilsa Ferreira." These are illustrative errors, not measured ones, but they show why a list helps.

How you add a word to dictation software

Nuance's help for Dragon says that to add a word or phrase you specify the word and its spoken form, and you can optionally train Dragon on its pronunciation ¹. The page describes an older desktop product and does not say how much an added word improves accuracy.

Platform limits also apply. On a Mac, Voice Control accepts up to 1,000 custom vocabulary terms, and you can record how each is pronounced ². The limit applies only in Voice Control languages that support a custom vocabulary. Many tools also offer text replacements, which swap one typed string for another after recognition. A replacement changes the output, while a vocabulary entry helps the recognizer hear the word in the first place.

Specialist vocabulary is where errors are most costly

Specialist fields use words that general recognizers rarely see. In a 2000 peer-reviewed study of physicians dictating medical reports, Dragon NaturallySpeaking Medical Suite 3.0 had a vocabulary recognition error rate of 14.1 to 15.2 percent ³. Those figures come from 2000 software, so they show the size of the problem and not the rates a current product reaches.

Custom words matter in any field with names, codes and jargon. A lawyer dictating a case note, a nurse recording a handover or an engineer naming parts can each add the terms that recur. A practical habit is to read the first few pages of output and add every word the software gets wrong.

Where the list is stored

In Dragon, custom words belong to the user profile. Nuance defines a Dragon user profile as a set of files that Dragon uses to process your speech, which stores information such as the type of microphone you use and your custom words ⁴. A list added to one profile does not travel with another person's dictation.

Other tools store the list in their settings, so check where yours lives before you move to a new computer. For more on the profile, see the entry on voice profile.

Where to read more, and related terms

To fix names and spellings step by step, read how to make dictation spell names correctly. For accuracy in general, see how to improve dictation accuracy and the guide on dictation mistakes. For the Dragon setup, read how to use Dragon NaturallySpeaking, and compare tools in the best dictation software, compared by need.

Custom vocabulary is a feature of dictation software. AI tools can use a list too, which is covered in AI dictation. Whether a vocabulary feature is included in a free tier depends on the app, so check each plan's limits.