sounds more like urmu instead of umu if this is just me please let me know
I’m not a native nor do I know much about the fine points of pronunciation like pitch accent, but 生むsounds fine to me. I can see why it might sound like urmu, but I think that is just individual variation on the speaker’s part. Alternatively, the pitch might just be tripping you up. The pitch diagram below is from OJAD - 韻律読み上げチュータ スズキクン for 生む, as you can see the pitch rises which is why the beginning may sound unlike you’d expect.
Speaking of variation though, the male pronunciation seems to be different than the female in a few ways, for example I notice the male version uses a lot more nasalization (for example in 上げる, 下げる, 出口), and it also tends to clip off the final ‘shi’ sound sometimes (as in 女子 and もしもし, but not in もうしもうし, or 市). Not sure if there’s been an explanation for this in the forums…
Kenichi uses a lot of rear placement when he speaks. Listen to the し in 市立. In that one it’s more obvious since Kyoko uses a lot of forward placement there, at least for the beginning of the sound.
The differences in し are more stereotypical for male/female speech and the differences in 生む are more stereotypical for older male speech vs standard. At least in my experience.