A ragged spy device

hello guys. i need help.

how can i make a simple device, that can detect sound (conversations), move towards the sound, avoiding obstacles and finally records the sound conversions and transmit them

That doesn't sound like a simple device at all. Detecting the direction sound is coming from is hard, telling whether sound is conversation or the noise from equipment or something is hard, and streaming audio will require something more powerful than a normal (8-bit AVR) arduino. That's in addition to the obstacle avoiding robot bit, which is at least something that people do and talk about alot.

Detecting sound is easy.
Differentiating conversation from the background noise, not so much.

Identifying the direction of the loudest noise, probably with a rotating, directional mic.
Turning a vehicle to move in that direction, sure.

Object avoidance - this opens up a large subject matter. I will leave it to you to google up any of the zillion projects that people have started trying to do this. Some with more success than others.

Recording sound for some time. The arduino is not much of a large data processor.
Do you need it recorded? Would turning on a transmitter be enough?

How will your vehicle know when to stop moving? If it simple moves towards the largest noise and avoids objects, won't it drive right up to the people having the conversation? This does not appear to meet your goal in the title.

cant i program the arduino controller to stop when it is 10m from the direction of the noise. i think a transmitter might work i was thinking of it.

but can a transmitter, sound sensor, obstacle detector be connected to one arduino.

Can you re-phrase that last post please?
It didn't make much sense.

it is 10m from the direction

I'm 33 feet from west?

The best way to accomplish this is to break it down into different tasks. I suggest starting with being able to detect noise.

okay guys