Lewis, who has been HR director at British multinational defence, security and aerospace organisation BAE systems for over five years, was speaking at the launch event for the report Releasing voice for sustainable business success, by think tank Tomorrow's Company, professional services firm Towers Watson and emploment relations organisation The Involvement and Participation Association (IPA).
The report looks at how active, confident and vocal employees and creating an environment in which they can speak up can help companies achieve sustainable success.
Lewis said: "Voice is important because it is addressing the largest challenge facing HR at the moment, which is retaining and attracting talent.
"Employees aren't just looking for a job anymore they are looking at a company to have a relationship with, and a relationship isn't a mute thing, a relationship involves having a voice from both parties, that for me is really critical."
He added: "It is up to HR to champion voice in the organisation."
Lewis described the "barriers" affecting an organisation having a voice and helping engage employees. He said: "We now have a generation of people who are looking for a relationship and don't come into a company and look up to senior management and see a hierarchy.
"This creates conflict because leaders in organisations tend to be people who work their way up the chain and buy into the concept of hierarchy. So that's why 'voice' can be important as it acts as a counterbalance to both parties. Because like any relationship the way of resolving conflict is by talking."
Lewis also mentioned a second barrier of leadership: "Some managers don't even interact with their staff. Their staff are simply 'little workers' - a concept that is old fashioned and ridiculous but still exists."
He concluded: "Employee voice is a real business function and it simply drives better business performance."
