Murphy's Grammar says that we use interested to ... to say how somebody reacts to what they hear/see/read/learn. And we use interested in doing something when we're thinking of doing it, we would like to do it.
But I've found these usages from Google News:
We're always interested in hearing about news in our community.
We will be interested in hearing the company's progress on these projects.
I would be interested in hearing any proposals he might have.
Should not interested to hear be used in those sentences?