The conventional uses of keyword research and optimization have been on their way out ever since the Panda update of 2011 introduced a new mechanism for content quality evaluation. Google no longer provides direct keyword ranking data, and because of Hummingbird's semantic search introduction, the majority of queries are handled based on context, rather than specific wording. Voice search is accelerating context-based searches and results, which means your specific keyword research and keyword inclusion efforts are becoming less relevant than tactics like long-tail keyword research and topic-based optimization. When people were forced to type keywords into a search bar, it was easier to predict the types of terms they'd search for; people opted to list as few words as possible, and made fewer queries. With the ease of voice search, people are searching more frequently, and in less predictable ways.