[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Voice is an intrinsic feature of marketing interactions that varies among individual agents, across encounters, and throughout interactions. Despite the prevalence of voice in marketing interactions and its importance as a communicative tool, it remains one of the least studied elements resulting in limited understanding of how voice contributes to interaction outcomes. This dissertation examines voice through systematic conceptualization of its verbal (linguistic) and vocal (acoustic) features and sheds light on how they shape business outcomes. In two essays, this dissertation investigates this pervasive, yet under-studied feature of marketing interactions and provides empirical evidence of the importance of its consideration in in marketing interactions. Essay 1: Organizational Agent Voice in Business-to-Business Customer Interactions. My first essay takes a crucial initial step in enhancing understanding of agent voice by providing a framework for studying voice through systematic conceptualization of its verbal (linguistic) and vocal (acoustic) cues and how they communicate meaning in B2B agent-customer interactions. Specifically, this paper addresses two research questions: (1) what dynamic customer voice measure can serve as a key diagnostic metric for understanding the impact of agent voice on interaction outcomes? And, (2) how do agent verbal and vocal cues interplay to impact key dynamic customer metrics during interactions? An exploratory empirical investigation that isolates verbal and vocal cues in a naturalistic B2B interaction examines these questions and finds that agents' verbal and vocal cues jointly influence customer receptivity, which in turn, acts as a strong mediator of agent voice on interaction outcomes. Implications for research and practice are discussed. Essay 2: The Role of Voice in Salesperson Lead Calling Effectiveness. In essay 2, I examine voice in a context of growing importance to practitioners: inside sales. Inside sales, or remote selling activities within a firm, are growing at an unprecedented pace due to their ability to substantially reduce selling costs while enhancing efficacy of traditional outside sales forces. Effective lead conversion is a, if not the, critical challenge facing the inside sales force. In this essay, I conceptualize verbal (ask specificity, communicating value, relating knowledge expression, customer-tailored inquiry) and vocal (confidence, affability) tactics relevant in inside sales lead calling and analyze their impact on lead conversion through acoustic and textual analysis of naturalistic inside sales phone conversations. This research draws on persuasion knowledge literature to conceptualize which verbal and vocal tactics are most effective in motivating lead conversion. Given poor conversion rate (20 [percent]) of lead calls, understanding ways to enhance sales efficacy would be welcomed by practitioners.