Question about mineoro DCH 85M

[g-sani]

I got a mineoro DCH 85M 2C and I would like to change the tone of the beeps that the detector produces.
It has a small speaker of 0.5W about 5cms in diameter and I don't like the beeps produced since they can be heard from a very long distance.
I would like to modificated it to produce the same sound as the new mineoros produce.
Can I just replace it by a buzzer?
What type?
How can this be done?
Any other info related to this mineoro model will be appreciated.
Thanks in advance
g-sani