https://www.mp3mymp3.com/ Easily record from any source, streaming audio, CD, turntable, cassette, phone or Skype calls, video games, microphone and more. MP3 my MP3 easily records the sound being processed by your sound card and saves your recording directly to MP3 or WAV format in real time.
https://hearthis.at/ Join the music community and listen to 1.000.000+ Tracks, Sounds and Mixes or upload your own.
https://en.wikipedia.org/wiki/Acoustic_fingerprint An acoustic fingerprint is a condensed digital summary, deterministically generated from an audio signal, that can be used to identify an audio sample or quickly locate similar items in an audio database.
http://online-audio-converter.com/ A free online app that converts audio files for you. The app supports all formats, processes your files quickly, and does not require installation.