Compound Grammar

A compound grammar combines multiple grammars together. All grammars combined together are activated at the same time when a recognition or an acquisition is performed. Priority is always given to the grammar that comes to the right of another. So if an additional grammar is combined with a first one and it defines the same choices, it will be the one taking precedence in the recognition. Compound grammars may have some special treatment based on the media chosen. For Cisco Media Termination (CMT) media termination, all Dual Tone Multi-Frequencies (DTMFs) are combined together to form a single grammar to be used when acquiring DTMF digits from a caller.

For example, the grammar expression: G[G1] || G[G2] || GG[Hello|dtmf-2] represents a compound grammar that activates the grammars G[G1], G[G2] and GG[Hello|dtmf-2] together with priority to GG[Hello|dtmf-2] over G[G1] and G[G2] and priority to G[G2] , over G[G1]. .