Does the 3.2 cm tumor include the portion in the inner ear (The cone of the ice-cream cone)?
My personal summary is:
1) Open surgery - effects felt immediately and some improvement may occur with time. Hearing is unlikely to be preserved.
2) Radiosurgery - almost no effect at first but a gradual desegregation over time. Hearing is unlikely to remain after 10 years.
3) Observation - no effect at first, but gradual decline in hearing. If it's stable in size, and over half don't grow after diagnosis, then that good. Hearing is still likely to decline, but slower than any other option.
There are many studies that support these statements and in the past I would quote them. Take a look at past forum entries and do a search. If you like I can research.