Google has created a free and open dataset called the Speech Commands Dataset.  It is targeted to neural network beginners to allow them to build models for simple keyword detection.

from the Googleblog website:

The dataset has 65,000 one-second long utterances of 30 short words, by thousands of different people, contributed by members of the public through the AIY website. It’s released under a Creative Commons BY 4.0 license, and will continue to grow in future releases as more contributions are received. The dataset is designed to let you build basic but useful voice interfaces for applications, with common words like “Yes”, “No”, digits...