RF in Slow Motion: Sonifying a Wi-Fi 7 Packet

• Wireless
• Communication
• DFT_FFT

At this week's Signal Processing Summit, Remington Furman gave a fascinating talk titled Sonifying the Tides, where he scaled recordings of tidal waveforms up into the audio range; literally letting us hear the rhythm of the oceans.

Following his lead, I applied the same idea to OFDM waveforms, consistent with an audio based platform called RadioSonic now under development by SigPro Labs. This platform will soon appear in new courses I will be offering enabling hands-on experiments in software radio and wireless signal processing with stand-alone real-time low-cost hardware.

The concept is simple but powerful:

Scale RF waveforms from the speed of light to the speed of sound, preserving wavelength relationships so that propagation, multipath, and modulation all behave similarly to what they would do in the RF domain, just slowed down to audio speeds.

The result is RF in slow motion.

For example, the figure below shows the spectrum of a 1.6 ms long WiFi packet (PPDU) as a 160 MHz OFDM waveform centered on Channel 164 in the upper 5 GHz band (carrier = 5.815 GHz). When scaled to audio using wavelength-equivalent mapping, the carrier would be at 6.65 kHz with a corresponding 182 Hz of bandwidth.  

In audio time, that same 1.6 ms RF packet stretches to over 23 minutes.   

Here is what the first 10 seconds of that 22 minute packet sounds like:  

160 MHz OFDM at 5.8 GHz, Sonified

For comparison, I frequency translated the same 5.815 GHz waveform down to 2.412 GHz (the 2.4 GHz Wi-Fi band). While real 2.4 GHz Wi-Fi signals occupy less bandwidth, this hypothetical case illustrates what a 160 MHz OFDM signal would sound like at that carrier frequency scaled to audio with the same wavelength ratio. In this case, the carrier maps to 2.75 kHz with the same 182 Hz of bandwidth.

Here is the resulting sound file:

160 MHz OFDM at 2.4 GHz, Sonified

I'll be sharing more about this approach as well as the new RadioSonic platform for "RF in Slow-Motion" at this year's 2025 DSP Online Conference, where I'll also lead a hands-on workshop on building high-quality variable digital delay lines. 

With these topics and the many other great presentations lined up, this year's conference is shaping up to be a great one. Get your pass today for unlimited access through August 2026, as well as access to many great past sessions.

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