This article reviews evidence on the use of 23 information and communications technology (ICT) platforms to project citizen voice to improve public service delivery. This meta-analysis focuses on empirical studies of initiatives in the global South, highlighting both citizen uptake (‘yelp’) and the degree to which public service providers respond to expressions of citizen voice (‘teeth’). The conceptual framework distinguishes two roles played by ICT-enabled citizen voice: informing
upwards accountability, and bolstering downwards accountability through either individual user feedback or collective civic action. This distinction between the ways in which ICT platforms mediate the relationship between citizens and service providers allows for a precise analytical focus on how different dimensions of such platforms contribute to public sector responsiveness. These cases suggest that while ICT platforms have been relevant in increasing policymakers’ and senior managers’ capacity to respond, most of them have yet to influence their willingness to do so.