Is there water sloshing in the phone?

For years now, when my daughter was walking outdoors, using her Apple airpods, what we could mostly hear was a very annoying background noise as if she were in a bathtub with water sloshing around. On numerous occasions, we told her that countless times, but every time she always remained in total denial, not being able to hear it for herself. 

 We were just exhausted from having that recurring conversation! I don’t know if you’ve experienced this from your next of kin or friends, but I after getting too much experience from my own offspring, I investigated to make sure I wasn’t dreaming and then what could cause that irritating noise of "water sloshing" or "underwater bathtub" sound, and overwhelmingly found out that it came from her Apple's noise-canceling ear pieces. 

In researching the issue, I found out that it could happen with many wireless earbuds, but AirPods were the worst offenders because of how their microphones and noise‑processing algorithms work. The AirPods use outward-facing microphones to pick up environmental noise so the internal chip can cancel it out or filter it during calls. 

When the caller is walking outdoors, ambient breezes or wind blowing directly across those small microphone meshes create severe turbulence. Instead of passing the harsh wind noise directly to the ears, the AirPods' digital signal processor (DSP) aggressively cuts and suppresses those frequencies in real time. 

This continuous, heavy-handed filtering creates a swirling, muffled sound that resembles water sloshing around in a tub or underwater pressure changes. Also, when walking briskly, each heel strike sends subtle vibrations up through the body. At the same time, her hair or clothing might have been lightly brushing against the stems or mic grilles of the AirPods. 

The noise-suppression algorithm tried to isolate her voice from these rapid, subtle thuds and friction noises, which further distorted the background audio into that "sloshing" texture. In digging deeper, I discovered a couple of quick fixes she can try on the AirPod’s user end. First, switch Voice Isolation On (iPhone Setting): During the call, she can swipe down to open the iPhone Control Center, tap Mic Mode, and select Voice Isolation. 

This uses machine learning to isolate her vocal cords specifically and cuts out almost all ambient background/wind artifacts. Then turn off Transparency Mode: If the individual is using AirPods Pro and has Transparency Mode or Adaptive Audio active, switching the AirPods to standard Off mode during windy walks reduces the aggressive mic processing transmitted through the phone call. 

Finally, clean the Mic Grilles: Over time, fine dust or lint trapped in the small black microphone meshes on the outer body of the AirPods can cause the algorithms to miscalculate wind, exacerbating the muffled sound. Clean grilles keep the processing running smoothly. Now, shut up, let your callers listen, and hopefully all they’ll get will be crystal clear!