You're a paranormal investigator interested in Electronic Voice Phenomen (EVP).
Using the Frequency Analysis 3000 your mission is to find high frequencies.
To do this, listen carefully and check out the audio visualiser (maybe show frequencies beyond human hearing range!).
Then you can record 10 seconds that you want so the machine starts searching high frequencies in those seconds recorded.

Controls:
Arrow Left/Arrow Right: Short jump (10 seconds)
Space: Start recording (only 10 seconds!)
Z: Restart audio
X: Resume / Pause audio

Result codes:
200: Waiting for data
302: Found
404: Not found

Music by ERH from freesound.org