On January 12th 2010, Haiti was hit by one of the largest seismic disasters known to date. At the time, seismic sensors, knowledge and risk culture were critically lacking. The dramatic social, political and economic consequences of the event revealed the importance of developing seismic risk reduction in Haiti. We present here the communication components of a citizen-seismology project in Haiti.. The project called OSMOSE propose to contribute to risk reduction by in installing low-cost seismic sensors (Raspberry Shake) at volunteers' houses to (1) collect seismic data and complement the national seismic network, and (2) engage with the population to understand their risk perception and the usage they could make of these tools. An international team of geoscientists, education specialists and social science researchers gathered to build an efficient communication strategy, which aimed at (1) informing the public about seismic risk and felt earthquakes, (2) establish a trust relationship with volunteers who host sensors, educate them about science and risk, (3) support the volunteers in their ambassador roles among their community. In order to establish a communication strategy that was inclusive and suitable to the local cultural context (including scientific literacy level, vodou culture, risk culture, past trauma, trust in the authorities etc), we first led a quantitative survey among the general public and a series of sociological semi-structured interviews with Raspberry Shake hosts who volunteered for the project. This enabled us to assess information expectations in terms of content and medium. Working with geoscientists, we then designed a first set of tools to respond to these needs, when possible. For instance, a website (https://ayiti.unice.fr/ayiti-seismes/) enables the public to know in a few minutes where an earthquake occurs and what its magnitude is, thanks to seismic data collected by the citizen network. It also displays educational information about seismology. The LastQuake app which crowdsources seismic data was translated into Creole for better access in the country. Finally, a WhatsApp group gathering volunteers and scientists has also been created given the importance of the messaging app in daily communication and information practices in Haiti. The group enables them to exchange information about the technical and scientific aspects of the Raspberry Shake they host and data they collect. During the August 14th 2021 earthquake, the group was used to share information about damage and rumors. Yet, this communication strategy is still incomplete and requires improvements. For instance, volunteers requested pedagogical support to better play their ambassador role among their community. Communication towards the general public also needs to gain visibility and accessibility. As part of an iterative process, additional interviews and assessment will help us improve the communication strategy. We will also include additional partners (such as schools, disaster management institutions, etc.) and test other methods such as a Virtual Reality tool. We argue not only that assessing the public needs is essential to build an inclusive and efficient communication strategy but also that the citizen-science approach is a strong asset to achieve this goal.