Background: A previously proposed Design Thinking-based Requirements Elicitation Process distinguishes between internal and external empathy as distinct sub-activities. To corroborate the effectiveness of this distinction, empirical validation is required. Objective: The main goal of this paper is to present a quasi-experiment carried out with the aim of comparing the use of the Vision Canvas technique for internal empathy and the Empathy Map technique for external empathy in requirements elicitation, assessing whether and how these techniques enhance stakeholder and requirements identification during Brainstorming sessions. Method: The quasi-experiment involved 138 undergraduate Computer Engineering students at University of Sevilla. Three treatments were considered: a combination of both techniques (Vision Canvas followed by Empathy Maps), Empathy Maps alone, and a control group relying solely on Brainstorming. Results: The results indicate a statistically significant improvement in stakeholder identification when using empathy-based techniques, particularly when both approaches are combined. Additionally, the analysis shows an increase in the number of requirements ideas generated with either technique compared to the control group. Conclusions: Although these findings support the distinction between internal and external empathy in requirements elicitation, further research is needed to determine the optimal application of these techniques across different contexts.