Collaboration in 3D environments has the main goal of attaining a high degree of teamwork by exposing the team to a suitable level of immersion. However, users within virtual environments have limitations to perceive the same stimuli of the real world. Particularly, the feeling of presence and nearness of the other is difficult to be generated in VR systems. This poster presents a work in progress that shows our current results on evaluating the impact of three different proximity cues for generating awareness of the presence of other. The design of each cue aims at independently stimulating the senses of sight, hearing and touch. The experiment design includes the comparison with a baseline condition in virtual environments where no specific stimulation is applied.