441 Royalty-Free Audio Tracks for "Mid Frequency"

Dl0ksc in cw qso of mar 10th, 2012, at 11. 50 utc on 10116 khz. Stable high frequency but multiple tone - spectrum. Audio frequency changes are due to my tuning of trx to hear multiple tone.

This is taken from (and an answer to) mxsmanic's "trip on métro line 9 in paris, france", at 2:20 exactly: metro on rails through the tunnel, which resonance creates this sound (very familiar to me as i live here). Interesting to notice that the sound's frequency stays around 483hz, which was (in the ancient solfeggio frequency science attributed to pythagoras) the frequency of "opening consciousness".

Created using lmms and the zynaddsubfx plugin with loads of automation on the filters.

Dead air static with a "singing" hum at 103. 3 on the fm radio dial, with the volume boosted and slight effect added.

This is a recording of very low frequency hum of a steel mill. The sample has been low pass filtered. The main frequency is about at 25hz. The sound was recorded some distance away of the steel mill area, where it mixed with other sounds as a constant hum, which could be felt in body too at certain spots.

Noise from a switched-off radio frequency receiver connected to an active recorder.

This is a part of the longer file "escalator hissing 1".

Buzzy patch of static from the am band of the radio dial. Slight flipping of the dial through the area adjusts the sound.

Noises from an old gdr tube radio (1966, oberon) when tuning through mw, lw and ukw bands. I tried to separate the different noises and let them be heard for a few seconds so you can edit the noises you need. First there's lw, then mw then a few noises from buttons on the radio then ukw at the end with fragments of some german radio stations in 2021.