In 2014, AVPreserve and the Northeast Document Conservation Center (NEDCC), with funding from The Andrew W. Mellon Foundation, undertook an in-depth, multi-faceted assessment to quantify the existing audio items held in institutional collections throughout the United States. This was performed in response to The Library of Congress National Recording Preservation Plan and its call for the appraisal of collections, as well as to establish a foundation for articulating the current preservation need of sound recordings in collections nationwide. Our goal was to acquire enough trustworthy data to be able to answer questions such as “How many sound recordings exist in broadcast organizations across the US?” or “How many sound recordings exist in archives throughout the US?” Moreover, we wanted to answer more complex questions such as “How many of such items are preservation-worthy?” or “How many have already been digitized?” Prioritization for digitization is as critical as both funding and timeliness. The foundation for action on all three of these fronts is trustworthy quantitative data. This paper aims to provide such data along with supporting information about the methodologies used in its generation.