This document discusses understanding customers through voice of the customer (VOC) research. It provides an overview of VOC, including different approaches, tools to collect and analyze customer data, and when in the product development process VOC should be conducted. The document also discusses objectives of VOC at different stages like ideation, planning and development. It emphasizes starting VOC early to understand customer pains, needs, and business objectives. Various frameworks for conducting VOC like S-P-I-N and prioritizing customer needs with Quality Function Deployment are also covered.