The term Natural Language Understanding (NLU) is generally understood as the ability of voice portals to understand a user speaking naturally. On the one hand, this is determined by the quality of the used speech recogniser and, on the other hand, by the chosen dialog strategy, the design of the dialog as well as the voice user interface.

At Excelsis, we define natural dialog management as the use of various technologies and methods of speech recognition and interaction to design a dialog that is as natural as possible to the caller.

Thereby, natural dialog management comprises the systems’ questions as well as the callers’ answers (or vice versa). When working on the callers’ statements, technologies such as barge-in, grammars based on rules or statistics and global commands (so-called hyperlinks) are used. Furthermore, multi-slot entries for complex entry forms are combined with a so-called mixed-initiative dialog to enable very unrestricted entries following system prompts.

The dialog’s naturalness is further enhanced by using n-best processing to improve the recognition of phonetically similar terms and implicit correction to rectify implicitly approved terms.

When it comes to system statements, a natural pronunciation is most important, no matter whether they are generated via audio-prompts or via TTS. To this end, a natural pronunciation formatting technology for dynamic data is used.

Applying the adapt-to-caller method, the system can adapt to the caller’s pronunciation habits. Thus, the comprehensibility as well as the call experience are improved substantially. Example: when entering numerical sequences such as postal codes, the voice portal understands all possibilities of pronunciation: digit by digit or in variations such as “seventy, one hundred and eighty-two”. Excelsis voice portals understand all of these entries and reproduce them accordingly when reprompting them to user.

Context sensitive help and random prompting complete the appearance of the speech dialog system or voice portal.

Advance your voice portal. We offer professional consulting,e.g.

- expert workshops

- training

- know-how transfer

- VUI design

- VUI analysis

- tuning