Sony WF-1000XM4 Review: Noise Cancelling Earbuds

After the WF-1000XM3 — genuinely innovative in their day but showing their age — Sony has finally refreshed its true-wireless earbuds, and with the WF-1000XM4 it offers the summit of its audio and technological craft. Has the Japanese firm produced the new class leaders? This review is based on that published test, not on a hands-on trial of our own.

Without reinventing the formula, Sony has clearly modernised it inside and out. The first big change is the charging case, which has been on a real diet. The old WF-1000XM3 case was one of the bulkiest around, all but impossible to slip into a normal trouser pocket; the new one is 40% smaller and fits almost any pocket, and it adds wireless (inductive) charging alongside USB-C. Build quality is good for the class without being luxurious — a fairly well-assembled, slightly light plastic with a lightly grippy finish and no play in the hinge.

The earbuds themselves are far more desirable. Gone is the elongated shape of their predecessors; the WF-1000XM4 adopt an almost spherical form, angled up towards the top of the ear. The construction is nearly all plastic, but the assembly and a few design touches — such as the little copper-accented tube housing a microphone — are so well judged that you could guess this was a high-end Sony without being told. There is now an IPX4 rating too, for resistance to splashes, though that is the norm today rather than a standout.

Sony says the earbuds are 10% smaller than before, and it shows most in how they balance in the ear: where the old model needed fiddling to sit securely, the XM4 feel more conventional — find the right tip from the small selection and a quarter-turn locks them in place. Comfort is good rather than sublime. The new polyurethane foam tips are more comfortable than the old silicone ones, though a classic silicone option would have been welcome for those who want it. The buds do remain bulky, which tells in smaller ears — not every ear shape will suit them — and they protrude noticeably, so they are not really cut out for sport. Sony has struck a fine compromise between hold and isolation, but for pure comfort the smaller in-ears from some rivals still have the edge. A nice touch: the packaging is entirely plastic-free, all card and recyclable materials.

The Sony Headphones app is among the most comprehensive there is, if a little complex, and the XM4 lean on it for a wealth of settings and automations. On the buds, a touch surface — effective, if a touch laggy — handles most functions: by default the left switches between noise cancelling and Transparency and triggers Quick Attention on a held finger, while the right handles track navigation and the voice assistant, and optical sensors pause the music when you remove a bud. The controls can be reassigned in the app by category — ambient-sound, volume, playback or off — though frustratingly you cannot keep both noise-cancelling and volume control at once, and the volume gesture is oddly unresponsive. More advanced options include hands-free voice-assistant wake words, a Speak-to-chat mode that pauses music when you start talking, adaptive noise cancelling tied to your activity or location, an equaliser, 360 Reality Audio and DSEE Extreme upscaling (whose benefit is hard to hear). Sony's new V1 chip does not transform the experience but usefully folds processing and Bluetooth into one.

Connectivity is thoroughly modern: Google Fast Pair and Windows Swift Pair, precise battery readouts, and a design where each bud receives the audio independently (either can be used solo). Multipoint was absent at launch — Sony cited signal stability, especially over LDAC — but a November 2022 firmware update finally added it. The standout is LDAC support up to 990 kb/s, a real feat on true-wireless earbuds, which lack the transmission power of a full headphone; Sony has clearly worked hard to keep it stable, though in practice LDAC can still stutter in congested environments or with the phone buried in a pocket. By default the buds prioritise stability and disable HD codecs, so you must opt into LDAC in the app.

The active noise cancelling improves again on an already-strong predecessor, favouring a very even, high-level attenuation across the spectrum rather than deep spikes, and it is especially good at damping sudden sounds such as keyboard taps. Is it the best? Not necessarily — the leading true-wireless models now sit within a whisker of each other, separated only by details. Passive isolation is better too, and the Transparency mode is among the more convincing, if not quite the most natural. Crucially, the hands-free calling is finally usable — a world away from the XM3 — with bone-conduction sensing helping isolate the voice in noise; not the very best, but a solid performer.

Battery life is a headline strength. Sony quotes 12 hours without ANC and 8 with; in testing the buds comfortably beat that, reaching around 9 hours 15 with ANC on AAC and about 13 hours 45 without — helped by the fact they play loud, so 50% volume is usually plenty. LDAC, as expected, is thirstier, dropping ANC endurance to roughly 5 hours 10, though that is still well optimised. A full charge takes about an hour, with 20 minutes enough for a 50% top-up, and the case adds roughly three more charges for about 36 hours in total.

Sound is where the most is expected, and Sony delivers. The 6mm driver is new — with a magnet-and-coil pairing 20% larger — and rather than the sharp V-shape of the XM3, the XM4 take a more all-rounder tuning, closer to Sony's WH-1000XM4 headphones. The result is powerful and rounded, slightly recessed in the treble but very intelligently judged for earbuds of this type, with well-controlled, tastefully lifted bass, nicely balanced mids and fine voice reproduction. Despite that gently softened treble, detail levels are excellent and the soundstage is remarkably wide and deep for true-wireless — potentially among the best of the breed. A crisp peak around the top end adds brightness and air, occasionally a touch artificial on cymbals but clean on most tracks. Only the Sennheiser Momentum True Wireless 2 comes really close on outright quality. Note that in passive mode the bass sits a little more evenly. All told, these are among the very best earbuds around — not the outright kings of balance, but proof that Sony has mastered its craft.

Polished from end to end, the Sony WF-1000XM4 tick almost every box: exceptionally long-lasting, strongly isolating, technically brilliant, blessed with an impressive array of settings, and much improved on hands-free calling. A top-tier product — one that could perhaps have pressed its advantage even harder on the touch controls, but a reference point of its generation all the same.