[alanmackenzie]

Work on making people feel safe with the situation before asking for direct feedback.

A few examples of how this could be done:

  Give them more than a few weeks to get comfortable with you and the company culture.
  Give concrete examples of things that have improved due to employee feedback.

It's hard to offer better advice through a HN post but easy to observe in person. Perhaps you can hire an external consultant to help or ask a mentor or advisor to fill this role by spending a few days in your office.