Generally I'd say that the LL has no right to record anything within the confines of the space that you lease...but what, precisely, are you leasing, the house, just one room of the house? If it's the house I'd say the LL has no right to have any cameras. If you lease a room and and the common spaces are common to all tenants then I'd say you have no expectation of privacy in any common space except the bathroom. I also don't know why you'd think that the LL has to notify you of any cameras that are put up.

As noted above, by agreeing to the lease, which permitted the LL to record audio, you may have tied your hands to prevent it. May.

I'd move at the earliest opportunity and until then I'd behave as if I'm being watched and eavesdropped on at all times.