Two likely reasons. First, the included "small" tip may not be small enough — brands vary widely in what they call S or XS. Try the Soundcore Liberty 4 NC's XXS, or purchase aftermarket XS/XXS tips (Comply, SpinFit, Final Type E) for your current earbuds. Second, the housing itself may be too wide for your concha. Tip size and housing size are independent variables. If even the smallest tip with a good seal still results in the bud slowly working out, the housing is pressing against your concha and ejecting the bud over time. The answer is a more compact housing — the JLab JBuds Mini or Sony WF-1000XM5 are your best options.

Completely normal and often optimal. Ear canal asymmetry — one ear slightly larger or smaller than the other — is present in most people. One TechRadar reviewer had both ears 3D mapped twice and found asymmetry both times. Using XS on your left and S on your right is not a workaround — it's the correct approach. The Sony Headphones Connect app and Apple's iOS Ear Tip Fit Test both test each ear independently specifically for this reason. Don't let the feeling of using "mismatched" tips put you off — it may be exactly right for your anatomy.

For most narrow canals, silicone in the correct (smallest available) size works better. Silicone creates a seal at the canal opening and stays there — it doesn't expand inward like foam. Foam's expanding property, while helpful for irregular canals, creates sustained lateral pressure in narrow canals that becomes painful after 30–60 minutes. The exception: if your canal is non-circular or irregular in cross-section (which you may not know until you try foam), memory foam tips like Comply XS can create a seal that no silicone option achieves. A good experiment order: try all included silicone tips first, then buy a pair of Comply XS foam tips as a secondary experiment.

Yes, very likely. ANC effectiveness is directly tied to acoustic seal quality. A properly sealed earcanal can achieve the 30–40 dB of noise reduction brands advertise. A leaking seal — caused by too-large a tip or housing pressure opening a gap — can drop that to 10–15 dB. This means a small-eared person with an improperly sized tip may perceive the same ANC headphone as performing far worse than a friend with average-sized ears using the same product. The fix: find the smallest tip that creates a perfect seal (test with the ANC+hum method in the tip guide above). The ANC improvement will be immediate and dramatic.

If pain persists after finding correctly sized tips with a good seal, the issue is likely canal wall pressure from insertion itself, not tip size. Three approaches: 1) Try shallow-insertion tips like Azla SednaEarfit or Final Type E, which create a seal at the canal opening rather than inside the canal. 2) Try the JLab JBuds Mini, which uses a slim 6mm driver and narrower nozzle specifically for this. 3) If all in-ear options cause pain regardless of size, switch to open-ear or bone conduction designs entirely — the Shokz OpenRun Pro 2 or Samsung Galaxy Fit clip-ons completely bypass the ear canal. For some ear anatomies, in-ear earbuds simply aren't a viable option.

Three quick tests. ANC test: enable ANC and hum gently — a properly sealed ear sounds hollow and ANC kicks in immediately. Bass test: play a bass-heavy track — a properly sealed canal has clear, present bass; a leaking seal sounds thin and hollow. App test: use the Sony Headphones Connect ear tip test or Apple's iOS Ear Tip Fit Test — both give a pass/fail result per ear. If any of these indicate a poor seal, move to the next smaller tip size, or try foam tips if you're already at the smallest silicone option in box.