If you want smaller-ear comfort, adaptive noise cancelling, and a quick top-up that adds four hours, choose Anker Soundcore; if you need real-time translation, call-focused microphones, and stated water-and-dust protection, choose Anker Soundcore P31i. For small ears, the Space A40 is my more convincing choice on the information available, while the P31i makes a stronger case for calls and travel features.
• Space A40: Its standout strengths are an explicitly ergonomic, compact design and up to 50 hours of total playtime. Its trade-off: the supplied information does not list a water-and-dust protection rating or translation features.
• P31i: It combines adaptive ANC, six microphones, real-time translation, and an IP55 rating. Its trade-off: a 10-minute charge is specified to add 3.5 hours, compared with four hours for the Space A40.
• Both offer adaptive noise cancelling, LDAC support, touch controls, and up to 10 hours of listening on a single charge under the stated conditions.
• Choose Space A40 if comfort for smaller ears and its listed charging details matter most; choose P31i if translation, calls, or its stated IP55 protection better match your routine.
The Space A40 makes its fit a central part of the pitch. It is an in-ear design with an ergonomic shape, and Soundcore describes it as smaller than its other ANC earbuds. That does not guarantee a comfortable fit for every small ear, but it gives buyers concerned about bulky earbuds a specific reason to consider it.
Its adaptive ANC detects surrounding noise and adjusts the noise-cancelling level to suit the environment. Soundcore also claims noise reduction of up to 98%; that figure is a product claim, not a promise that every sound will disappear. For commuting, working in a shared space, or listening while traveling, automatic adjustment may be more convenient than choosing a level yourself. The supplied details also include touch controls and app control.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-21 · 6 min read · Independent comparison
Battery life is another clear strength on paper: up to 10 hours per charge and up to 50 hours with the case. A 10-minute fast charge is listed as providing four hours of listening. The double-layer diaphragm drivers are described as delivering strong bass, clear mids, and bright treble, while LDAC support offers a higher-detail wireless listening option.
I would look closely at the Space A40 if comfort is your first concern and you want a long stated runtime without giving up adaptive ANC. I would not choose it for translation, a specifically stated IP55 rating, or the P31i’s listed six-microphone call setup; those features are not in the Space A40 information provided. If those are the deciding factors, the P31i deserves a closer look.
The P31i is the more feature-packed option for someone who wants earbuds to do more than play music. Its adaptive ANC adjusts to the surrounding noise, with noise reduction stated as up to 52 dB. That is a different kind of specification from the Space A40’s “up to 98%” claim, so I would not treat the two figures as directly comparable measures.
Its most distinctive extra is real-time AI translation in more than 100 languages. That may appeal to travelers or anyone who expects conversations across language barriers, though the provided information does not spell out all the conditions or setup requirements. For voice calls, the P31i lists six microphones, AI noise reduction, and wind-noise reduction. These features make it the more clearly equipped pick for frequent calls, particularly when outdoor wind is a concern.
The P31i also supports LDAC and Hi-Res Audio, with spatial audio listed among its features. Its battery figures are up to 10 hours on a charge and up to 50 hours with the case; with ANC on, the stated figures are eight hours per charge and 40 hours total. A 10-minute charge is listed as adding 3.5 hours of listening. It also carries an IP55 rating, a concrete advantage for buyers who want a stated water-and-dust protection rating.
I would consider the P31i if translation, microphone features, or its IP55 rating maps to how you will use earbuds every day. Its supplied design details identify an in-ear bud shape, but they do not make the same explicit small, ergonomic-fit claim as the Space A40. If your main question is whether earbuds will suit small ears, the fit information here gives the Space A40 the clearer case.
Side-by-Side: Which Should You Choose?
• For translation features → P31i. It lists real-time AI translation across more than 100 languages; no translation feature is listed for the Space A40.
• For frequent voice calls → P31i. Its six microphones, AI voice-noise processing, and wind-noise reduction are specifically described. The Space A40’s supplied details do not list comparable call-microphone features.
• For the quicker listed fast-charge top-up → Space A40. A 10-minute charge is stated to provide four hours, versus 3.5 hours for the P31i.
• For stated protection against water and dust → P31i. It has an IP55 rating in the supplied information; no equivalent rating is listed for the Space A40.
• For ANC with both models offering adaptive adjustment → either. Both are described as detecting surrounding noise and adjusting ANC. Their stated reduction figures use different measures, so I would not pick one based on comparing those numbers alone.
• For Hi-Res listening with LDAC → either. Both list LDAC support. The P31i also lists spatial audio, while the Space A40 highlights its double-layer diaphragm drivers and a sound profile described as strong in bass, clear in mids, and bright in treble.
• For a small-ear alternative to on ear headphones → Space A40 is the more relevant fit to consider. These are in-ear earbuds, not on-ear headphones, and the Space A40 has the more explicit compact-fit description.
My Verdict
In my opinion, I would choose the Space A40 for small ears because its compact, ergonomic design is the clearest fit-related advantage in this comparison. Its adaptive ANC, up to 50-hour total runtime, and four-hour fast-charge claim round out a practical everyday package.
The Space A40 has the clearer fit-related claim: it is described as smaller than other Soundcore ANC earbuds and designed with an ergonomic shape. The P31i’s supplied details identify an in-ear bud shape but do not include the same explicit small-fit description.
Both list adaptive ANC that adjusts to surrounding noise. The Space A40 states noise reduction of up to 98%, while the P31i states up to 52 dB; those figures use different units and should not be compared as if they were the same test.
The P31i is the more feature-specific choice for both. It lists six microphones and noise-reduction features for calls, along with real-time translation across more than 100 languages. Those features are not listed for the Space A40.
Both list up to 10 hours per charge and up to 50 hours with the case. The P31i specifies up to eight hours per charge and 40 hours total with ANC on; a 10-minute charge is stated to add 3.5 hours for the P31i and four hours for the Space A40.
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