Do native English speakers pronouce b as m?

I very often study English and try to improve my listening skill with some educational materials. And I just encountered a sentence, "Once he made an alarm clock for cats – you know, to wake them up from their naps." However, the speaker speaks the last part of this sentence as follows, "tweiktheba^(p)from". That sounded very weird to me, since I thought she should’ve probably pronounced like "tweikthema^(p)from" in place of "ba". So I once sounded exactly like her and spoke it to the Google Translate app, and, surprisingly, it worked and translate b to m.

ex. I will wake them up from their naps.

aiwoweiktheba^from

So my question is that do native English speakers sometimes pronounce b as m?