Best swimming headphones for audiobooks: storage, formats and the Audible problem

Why Bluetooth is not an option

Bluetooth is a 2.4 GHz radio and water absorbs it almost immediately. H2O Audio says so plainly on its own product page: Bluetooth does not work underwater, so use MP3 or its PLAYLIST+ mode. Every set on this page therefore carries a memory chip, and you copy files onto it over USB the way you did in 2007.

That has one large consequence for audiobook listeners, which the rest of this page is about: you are not streaming an app, you are loading files. The app you currently listen in probably will not let you.

The table

The Audible problem

This is the thing nobody tells you until the files will not copy. Audible's own compatible-devices list covers phones, tablets, computers, Apple Watch, Kindles and a small set of accessibility players. A general-purpose MP3 player is not on it, and neither is any swim headphone. Audible downloads are wrapped so that they play inside Audible's apps on Audible-supported hardware, which none of these are.

What to load instead

Public-domain audiobooks. LibriVox records books whose copyright has expired, read by volunteers, and states that all its audio is in the public domain and may be used for any purpose. It is the easiest legitimate source of plain audio files, and it is free. Several thousand titles deep, and the classics are all there.

Podcasts. Most podcast episodes are plain MP3s with a direct download link. For a 45-minute swim, an episode is a better length than a chapter anyway.

DRM-free audiobook stores. Some publishers and retailers sell audiobooks as ordinary files you own and can copy. Check the product page for the words DRM-free before you pay.

Recorded streaming, on the H2O only. H2O Audio's PLAYLIST+ records streaming audio to the headphone's 8 GB for offline play, which is its answer to exactly this problem. It is a genuine differentiator and the reason the TRI 2 PRO ranks second here despite costing more than the Shokz.

On formats, the OpenSwim Pro is the most permissive set here: Shokz lists MP3, FLAC, WAV, AAC, M4A, APE and WMA. H2O says it takes most music formats including iTunes .M4A. If your files are already M4A, both are fine.

Battery, in hours of listening

Memory mode is more demanding than Bluetooth on some of these and less on others, so read the mode-specific figure. The OpenSwim Pro is rated 9 hours on Bluetooth and 6 in MP3 mode. H2O quotes 6 hours in memory mode and 6 to 9 overall. The Mojawa Run Plus is 8 hours and the Creative Outlier Free Pro is 10, the longest here.

For an audiobook listener that ordering matters more than it would for a swimmer playing music, because you are listening in long continuous runs rather than in 40-minute sessions. An unabridged novel is eight to fifteen hours; only the Creative gets through a short one on a single charge.

Storage is not the constraint people expect it to be. Spoken word is usually encoded far lower than music, and at a typical 64 kbps a recorded hour is roughly 29 MB, so even the 8 GB players hold more books than you will listen to in a season. Buy on battery and formats, not on gigabytes.

Buyer's guide: listening to books in a pool

Split long files into chapters before you copy them

These are players with buttons, not apps with bookmarks. A single fifteen-hour file is miserable to navigate with wet hands. Chapter-sized files, named in order, are the difference between enjoying this and giving up on it.

Check how the unit resumes

Behaviour on power-off varies between models and firmware versions, and none of the makers document it well. Test it in the shower before you rely on it for a long swim.

Fit under a cap, and use the plugs

Bone conduction works better underwater than in air, because water transmits vibration well, but only if the transducers stay pressed to your cheekbones. A swim cap over the band helps. Earplugs help more: with your canals plugged, the bone-conducted sound is no longer competing with splashing.

Rinse in fresh water after chlorine

An IP68 or IPX8 rating is about water ingress, not about what pool chemistry does to seals and contacts over two years. Rinse, then dry the charging points before the magnetic cable goes on. More at IPX7 earbuds in the shower and the pool.