Apple AirPods 4 ANC review: Compact design, colossal sound

The Apple AirPods 4 ANC are impressive semi-in-ear headphones with a strong set of features. When put to the test, the active noise cancellation proves highly effective, while the sound quality of these TWS headphones is particularly outstanding. Transparency mode is equally impressive and the head gesture controls are very practical for everyday use.

As expected, the full range of features is only available within the Apple ecosystem, though the AirPods 4 are compatible with other platforms. Their design means the headphones may not sit securely in every ear, making them less suitable for use during sports. The battery life isn't as good as we would like.

The Apple AirPods 4 ANC are available directly from Apple, but they can be found at a lower price on platforms like Amazon.

Apple's AirPods have entered their fourth generation. For the first time, Apple offers a model with active noise cancellation (ANC), which we examine in this review. The semi-in-ear headphones feature Spatial Audio, support head gesture controls, are IP certified and have a sleek, compact design.

The Huawei FreeBuds 5 and Xiaomi Buds 5 are based on similar concepts.

The Apple AirPods 4 ANC are only available in white and come with a compact, well-designed charging case. The earbuds are IP54-certified, meaning they are protected against harmful dust and splashes of water, offering all-around resistance for everyday use. This makes them suitable for light rain or sweaty workouts, though they should not be submerged. It's important to note that this certification applies only to the earbuds, not the charging case.

The build quality is excellent, with the earbuds and case showcasing a seamless, premium finish. Strong magnets ensure the case lid and earbuds are securely held in place. With their semi-in-ear design, the AirPods 4 ANC rest gently in the outer part of the ear rather than sitting deep in the ear canal. While this design enhances comfort, the fit can vary depending on the shape of the user's ears. Unfortunately, this may not provide the stability needed for sports, as the earbuds even slipped out during a leisurely stroll when we put them to the test.

That said, they are exceptionally comfortable to wear and cause no pressure to the ears. However, due to their design, they offer limited passive noise isolation, allowing some external sounds to pass through.

The Apple AirPods 4 ANC come in compact packaging that is completely plastic-free and made from fibre-based materials.

Apple does not provide a dedicated sustainability report for any of its headphones. However, the press release includes some details about their environmental aspects:

"The design of the new AirPods 4 incorporates 100 percent recycled rare earth elements in all magnets and 100 percent recycled gold in the plating of multiple circuit boards. The case also features 100 percent recycled tin in the solder of the main logic board and 100 percent recycled aluminium for the hinge. The AirPods 4 are also free from potentially harmful substances such as mercury, brominated flame retardants (BFR) and PVC." 

According to the experts at iFixit, the AirPods 4 cannot be repaired, either by the user or by a third party. However, replacement parts can be ordered individually for lost headphones or a lost case.

The AirPods 4 ANC support only the most widespread Bluetooth audio codecs SBC and AAC, but Apple impressively demonstrates that good headphone tuning is more important than having the most powerful codec. This is clearly evident in the pink noise measurement, as we haven't tested any in-ear or semi-in-ear headphones that offer such a balanced soundstage. This makes a noticeable difference and the AirPods 4 truly impress in this regard, providing an outstanding sound experience that can also be customised to suit individual preferences.

The ANC performs exceptionally well for a semi-in-ear TWS, and, at the time of testing, it is the most powerful of its kind. Transparency mode impresses with its natural sound transmission and minimal background noise. Adaptive voice detection functions reliably, though the suppression of background noise during phone calls is less effective in louder environments.

THD (Total Harmonic Distortion):

Total Harmonic Distortion quantifies the proportion of harmonic components that arise due to nonlinear distortion (harmonic content) in relation to the original signal. THD considers only the fundamental harmonic component. The distortion factor is often mentioned in the same context but refers to the entire signal.

THD+N (Total Harmonic Distortion + Noise):

This value is similar to THD but, in addition to the harmonic distortion components, it also accounts for noise as an effective value.

To measure these values, a low-harmonic sine wave signal (1 kHz, > 0 dB) is played through the test headphones. A linear measurement microphone (placed approximately 1 cm away) inside an artificial head captures the output.

Both values are expressed as percentages; the lower the value, the better the signal fidelity.

Apple claims the AirPods 4 ANC offer up to five hours of battery life, extending to 30 hours with the charging case, though it provides no technical details. However, thanks to this teardown analysis by iFixit we know the product's key specifications. The charging case contains a 1.329 Wh (3.852 V, 345 mAh) battery, while each earbud has a 1.23 mWh battery, equivalent to approximately 32 mAh. Compared to some competitors, these batteries are relatively small.

In our test at 65 dB(A) with adjusted volume, we had to forgo the ANC, as wear detection only activates it when the earbuds are in use. Battery life exceeded Apple's official claim, reaching nearly seven hours of playback — an impressive result. However, in everyday use, performance varies due to adaptive features. Depending on media volume and background noise, battery life can sometimes be cut in half.