Digitization of sound by a microcontroller and transmission to a server via Wi-Fi?

Question

Circuit design

Good afternoon. I ask for advice on the implementation of one hardware-software thing.
Task: a small device on a microcontroller with a microphone and Wi-Fi records sound on the server. A kind of wiretapping, but in a different context. I ask you not to scare the laws of the Russian Federation, the device is for yourself.
Implementation questions:
1. Will an 8-bit AVR with quartz (conditionally 16-20 MHz) be enough to record and simultaneously transmit the frequency range of a human voice (from 300 to 3400 Hz)? Or immediately based on a more powerful STM32?
2. Will a cheap module based on esp8266 pull continuous operation without freezes? I've read that it can be a problem.
3. What about the server part? I am a little familiar with PHP, but you will not accept data using the GET or POST method ... As I understand it, you need to make a TCP server and listen to the port. But I'm not familiar with this area, give me a direction where to dig.
Thanks to all. I will be glad to any advice and tips within this subject area.

Answer 1

take stm32, attach a SD card to it, press the sound on it into files and give out files via http, for example, a lot of simple web servers are written in C, you just have to google it.
Avr theoretically cope with this task, but at the limit, it’s better to take stm, with a margin.

Answer 2

Somewhat redundant solution, but still: geektimes.ru/post/257382

Answer 3

esp8266 - all in one package - both micro and wifi.
there is an example for playing sound through dac . By analogy, you can write capture. adc is there too.