An Arduino can do this, but this is a very advanced problem on an Arduino. It sounds like perhaps you need something more plug-and-play. In that case, buy a Raspberry Pi 4 starter kit and a USB microphone, and start working on the problem from there. The Raspberry Pi 4 is a Linux computer, so everything you do will be writing scripts or programs (in any language: it's just a regular computer, so use Python, C, C++, Java, bash, whatever you want) to run on its Raspberry Pi OS (formerly called Raspbian) Linux operating system.
If you go this route, you'll want to ask your questions on the Raspberry Pi Stack Exchange as well.
Keep in mind the question you asked is too broad. You are generally expected to do your own background research and then ask more specific questions, demonstrating what you've already tried.
Getting an Arduino to send out microphone data is, like I said, a very advanced subject and project (think: professional level / expert hobby level) unless you can Google and find pre-made libraries and how-tos on the subject.
Essentially, for the Arduino Uno route you'd need to do some fancy high-rate ADC sampling with a modified ADC clock rate in a special ADC mode which takes repeated samples and then interrupts your code when a sample is ready, rather than just doing normal
analogRead() since that is both blocking/polling-based which wastes clock cycles and creates sample jitter which causes audio distortion, and then you'd need to send this data via some Wifi shield (add-on board) or an ESP8266 or something, or via some other technology (wired or wireless) to a computer to pass it on to the internet. This may involve binary packetization/bit-packing, error checking, buffering, etc., all of which is its own special skill to acquire.
Some of my projects have taken me 3+ years to complete them, since I began complicated projects as a beginner. This is one of those multi-year type projects for a beginner for sure.
(Heck, if you give me two LEDs and two resistors and an Arduino Nano, with those items alone, I can send you on your way to work 8 hrs a day for 3 months straight on projects. It's easy to under-estimate the complexity of something until you're neck-deep in it.)
Update: if you want to go the Arduino route, here's some tips to get you on a search route more likely to get you to a solution faster. Again, no doubt an Arduino Uno can do this. It for sure can. But, a faster Arduino can do it easier and better. So:
- Google search for projects on Adafruit which may do this. Ex: Google search for "adafruit stream audio". Their tutorials are 2nd to none--the best in the world--and their products top-notch.
- Search for projects on Sparkfun which may do this. Ex: Google search for "sparkfun stream audio". They also are excellent and have world-class tutorials.
- Search for projects which do this with a Teensy, Zero, Due, or other high-speed 32-bit microcontroller, instead of an Uno. Audio processing is more difficult for a slower 8-bit Uno than for any of those 3 Arduino/Arduino-compatible devices.
- Also look on Instructables.com for tutorials and help.
- One more thought: Google search for "atmega328 stream audio to wifi" (an Uno uses the ATmega328 microcontroller, so that's a good search term to use)
Update: also take a look at this tutorial by GreatScott (who is also super awesome) (https://www.instructables.com/id/Make-Your-Own-Spy-Bug-Arduino-Voice-Recorder/), which uses this AVR-based (for ATmega328: Arduino Uno, Nano, Pro Mini, etc., or ATmega2560: Mega) advanced audio library for both recording and playing back audio. See:
- Recording Audio
- Audio streaming over NRF24L01+ radio link