According to Sony, the new headphones "offer all the much-loved technology" of the WH-1000XM3, but come with "additional intelligent features that allow you to personalize and control your music, improve noise cancellation, and adjust ambient sound automatically".
Those improvements haven't led to a price increase in most regions compared to their predecessors; available in black and silver, the Sony WH-1000XM4 will set you back $349.99 / £350 / AU$549. (UK readers will notice a slight price increase, however, as they XM3s cost £330 at launch.)
We've tested the new headphones thoroughly, and, spoiler alert: we're in love. Be sure to read our Sony WH-1000XM4 Wireless Headphones review for all the details.
Better noise cancellation
The new Sony WH-1000XM4 look pretty much identical to their predecessors, with most big changes taking place under the hood.
Sony says that the WH-1000XM4 deliver the company's "best-ever noise-cancelling performance, reducing high and mid-frequency sounds".
Each earcup comes with with two built-in microphones to capture environmental sound and apply noise-cancelling processing "in real time".
Like the Sony WH-1000XM3s, an Adaptive Sound Control feature senses where you are and adjusts the level of noise cancellation in response. As Sony explains, "over time, Adaptive Sound Control learns to recognize locations that you frequently visit such as your workplace, gym or favorite café, and tailors sound to suit the situation".
If you need to have a quick conversation, a new Speak-to-Chat feature means you can simply start speaking and the headphones will stop your music and allow ambient sound to pass through the earcups – handy if you're in a hurry.
Your voice should be picked up pretty accurately, whether you're activating Speak-to-Chat or talking on a phone call; Sony says its new Precise Voice Pickup technology applies "audio signal processing" to pick up voices clearly and precisely.
You can also place your right hand over one earcup to briefly allow ambient sound to passthrough, which is useful if you need to hear an announcement while traveling.
Another new feature for the Sony WH-1000XM4 is wearing detection; that means that the headphones automatically stop your music when you take them off, thanks to a built-in proximity sensor and two accelerometers.
Sony says that this feature helps to save battery life – though with 30 hours of playback with noise cancellation turned on, the XM4s should get you through the week easily.
We thought the Sony WH-1000XM3s were among the best-sounding headphones for two years running, and it seems as though the XM4s could sound even better.
That's because Sony's Edge-AI technology is designed to "rebuild audio lost during digital compression for a full fidelity experience".
According to Sony, it works by analyzing music in real time, recognizing "instruments, music genres. and individual elements of each song to restore the high range sounds lost in compression".
That could offset some of the audio fidelity that's lost when you swap out cables for a wireless connection.
As with the XM3s, these headphones offer 360 Reality Audio, Sony's proprietary immersive audio format, which makes your music sound as though it's coming at you from all angles.
There are more features to come, too; Sony says that the ability to pair the headphones with multiple devices will come via a firmware update in the future.