Buddhist perspective how humans can communicate with spirits? I have seen lot of paranormal activities videos about scientists who have done lot of research in spirit communication and are successful in doing so. Can this be done or possible? What are the ways this can be achieved according to Buddhism?
Yes this can be done if you develop abhiññā. It will be through ceto-pariya-ñāṇa. In order to do this you have to develop at least the 4th Jhana.

Also there are more recent documented instances where this has been done in Venerable Ãcariya Mun Bhuridatta Thera's biography. The general training that was followed recorded in Patipadā Venerable Ãcariya Mun’s Path of Practice. (Ajahn Mun Bhuridatta Thera was a teacher of Ajahn Chah)

Also refer: 


p369, CH. XII THE SUPERNORMAL POWERS, The Path of Purification, 4td Ed., Bhikkhu Nanamoli (trans.)
p206, The Path Of Freedom (Vimuttimagga) of Arahant Upatissa Translated from the Chinese by Rev. N. R. M. Ehara, Soma Thera, Kheminda Thera
Ways of Attaining Dhyana by Piya Tan
Miracles by Piya Tan


Also be warned that only a few a successful in developing supernormal powers and this can become a hindrance, hence you are better of working towards liberation.