In today's digitised workplace, it is important to understand how employee voice is affected by new technologies. Adopting a novel interdisciplinary approach, this paper uses the Escalator of Participation framework and the Technology Affordance lens to explore how modern communication technology, such as social media (SM), compares to traditional voice mechanisms. Findings from 52 in-depth interviews of managers and employees from two multinational subsidiaries show that SM provides new ways of voicing in synchronous and asynchronous settings that traditional voice mechanisms do not offer. Despite this, employees do not always choose SM for all voice types due to employees' perception that SM was suited better for some types of voice more than others and also being mindful of managerial preferences for non-SM mechanisms. We also provide implications for future research and practitioners through highlighting that the effectiveness of voice on SM is shaped by SM affordances, issue type, employee awareness of likely responses, and managerial willingness to engage constructively with voice on SM.