The AirPods Pro 2 ANC, Strong when It Wants To: How to Improve It?

This post reports on my experience with the active noise cancelling function (ANC) of the AirPods Pro 2 in daily life.

We are also looking at measurements and tips/hacks on how you can improve the noise reduction performance.

This article is from the perspective of a noise sensitive person. So far I have been using these earbuds for about six weeks.

Let’s get right into it.

Along a loud road, the AirPods Pro 2 very effectively reduce the low frequency rumble of passing trucks and buses.  At times, they do it so well that the focus shifts from hearing the trucks to feeling them in the chest.

The ANC also generally works well against air cabin noise, on public transport, and in malls.

In my bedroom, however, and other places with little background noise, even much quieter truck resonances than I am experiencing outside and other intermittent noises can get right through to my ears.

And, in quiet settings, intermittent noises stand out.

At first, I thought maybe I am not getting a proper seal with the ear tips, so I ran the AirPods’ iOS fit test again and again and made adjustments to the fit.

A poor seal typically leads to impaired noise cancellation (I will address this later in this article).

But, I almost always passed the fit test.

I also updated to the latest firmware (happened automatically after upgrading to iOS 16), but that only improved the situation marginally.

How can it be that louder trucks (outside) are effectively subdued when quieter ones (inside) are not?

Adaptive noise cancelling

It turns out that the AirPods Pro 2 automatically change the noise cancelling strength depending on the environment you are in.

The Pro 2’s ANC is adaptive.

(Note: I am not referring to adaptive transparency mode. That is a different function, designed to help against very loud noises while allowing you to hear your surroundings.)

The earbuds also change the way the ANC targets certain frequencies in response to the noise they detect.

You might, for example, get different attenuation curves when the earbuds attempt to cancel heavy traffic noise, a vacuum cleaner, or the noise in a coffee shop.

This can lead to stunningly good results against single noise sources.

In the case of my bedroom, however, the earbuds apparently determined, “this is a quiet place, I don’t need to do much.”

The problem is that my bedroom is mostly but not always quiet!

I don’t usually hear car traffic, but the rumble of trucks and the roars of super-loud bikes with “modded” mufflers can even be heard through walls.

Unfortunately, the Pro 2 often don’t crank up the ANC fast enough (or not at all) to help against these and other intermittent noises (e.g., door slams).

At times, the earbuds did almost nothing while at other times they helped quite a bit. So apparently they have it in them; they can do better.

Alas, “Hey Siri, watch out for trucks, didn’t work,” and their is no max ANC switch either.

I decided to run a systematic noise reduction test (my ears) with pulsed noises at increasing frequencies.

Additionally, I varied the room background noise level by changing the fan speed of my AC unit to see how that affects noise cancelling performance:

• Off & speed 1 (ca 37 dBA @ my bed’s headboard)
• Speed 3 (40 dBA)
• Speed 5 (43 dBA)

Take a look at the noise reduction (in decibels; the higher the line, the better) against the same pulsed noises at different background noise levels:

Wow, what a jump: The light and dark blue lines show the noise cancelling performance against the pulsed noises when the room background level was 37 decibels (i.e., AC off or lowest fan speed).

In contrast, the green and the orange lines indicate the performance against the same pulsed noises with a background noise level of 40 and 43 decibels, respectively.

In the range from 40 to 100 Hz—the range in which the truck rumble lies: the ANC’s effectiveness more than doubled when the background noise level (produced by my AC’s fan) was at least 40 decibels.

Basically up to 2000 Hz, there is a substantial performance difference between quiet and moderate background noise.

Notes:

• At and above 2000 Hz, it looks like the noise reduction is entirely due to the passive noise isolation the ear tips provide. In fact, against frequencies >6 KHz, the stronger ANC lead to a somewhat reduced performance.
• I would like to see more passive noise isolation against high frequency noise (>2.5 KHz), e.g., screeching brakes. In that range, perhaps foam ear tips could help.

Hack to improve the ANC of the AirPods Pro in a quiet room

Create moderate-volume continuous background noise, for example, by increasing the speed of your AC fan until you notice an improvement in the noise reduction performance.

If you don’t use AC/a fan, you could also play pink noise through a speaker or white noise machine at a moderate volume.

Note: If you want to experiment further, the post How Loud Should White Noise Be for Adults includes info on measuring the noise level in your bedroom.

In my tests it was better to keep the machine at the foot end of my bed.

At times, when the white noise machine was on my night stand (or too loud), the ANC focused on cancelling the white noise (loudest in the higher bass and lower mid frequencies due to the white noise machine’s small speaker), which somewhat decreased the Pro2’s performance against the truck frequencies.

So yes, the ANC is fickle in quieter environments.

This brings us to the second point, ear tip fit.

Ear tip fit and ANC effectiveness

When you don’t get a good seal with the ear tips, the ANC appears to adapt to that as well to give you at least some noise reduction. I quite like that.

In my experience, a poor fit does, however, still negatively affect noise reduction.

For me, the AirPods 2’s L-size ear tips do provide a decent seal, but they are on the small side. When I open my mouth, e.g., laugh, the seal becomes weak and noise, in particular low frequency noise, seeps in.

In my opinion, Apple should additionally include/offer XL-tips.

Already with the first generation AirPods Pro, there were multiple reports by people who found the L-size tips too small. Perhaps not including XL-tips was a tradeoff to keep the size of the case.

How do you know you are getting a good seal?

iOS AirPods Pro ear tip fit test

As mentioned earlier, iOS includes an ear tip fit test. I recommend you run that test at least initially to determine what size ear tips you need.

Occlusion effect fit test

In addition, however, I recommend you use the occlusion effect to test how well your ear tips seal your ear canal.

For me, this test is faster and it helps even more for getting a good fit with the AirPods Pro than the built-in test:

With the earbuds in your ear and noise cancelling completely turned off (not in transparency mode), slowly pronounce the following words several times:

“Boom, Beak.”

If you are getting a good seal, the words should sound “bassy/boomy.”

If they don’t, adjust the fit of your earbuds until they do. Make the words sound as boomy as you can.

When you turn on noise cancelling, the boomy sound should go away and return when you turn it off again.

You can use this test at any time without taking out your phone or when your AirPods are connected to an Android phone or a computer, for which there is no fit test app available.

To perform the test whenever you like and regardless of which device you are connected to, I recommend you add noise cancelling Off to your AirPods:

This allows you to cycle through three modes by long-pressing the stem: Noise cancellation, Transparency, and Off.

To add noise cancelling off to your AirPods, you need access to an iPhone/iPad. But once set up, you can perform this fit test at any time, including when using the AirPods with an Android phone or Windows PC.

Third party ear tips

There are plenty of third party tips out there, which could be an option if you dislike the silicone tips that come with the buds.

I find the silicone tips comfy, but rather am looking for larger tips. So far I have come up empty.

I have tried third-party L-size foam tips (no-name), but they didn’t work better than the tips that come with the buds. I may still try Comply foam but they also don’t come any larger than L-size (S, M, L).

As mentioned earlier, the space provided in the charging case might limit the ear tip size third-party providers can offer. Perhaps a bit larger is possible. We’ll see.

The ANC automatically selects what to focus on but it doesn’t always get it right

The AirPods Pro 2 don’t allow the user to choose a fixed noise cancelling mode or adjust the ANC; they determine automatically what noise needs most cancelling.

I have found this to work quite well against airplane cabin noise, vacuum cleaners, hair dryers, etc.

In most cases, this also works along busy streets and in louder coffee shops.

However, when the AirPods choose an attenuation curve that focuses on cancelling lower mid-frequency noise, they appear to become less effective at cancelling low frequency noise. The opposite can also happen.

I have observed this effect multiple times in coffee shops.

For example, the earbuds might focus on reducing the coffee shop’s HVAC system and chatter. But as a consequence, the rumble of passing trucks isn’t reduced nearly as well as it could be.

I have also had it that the ANC first reduced a low frequency hum (AC hum) present in my room very effectively—only to then focus on the fan when I slightly turned my head, making the fan quieter and the hum return.

The problem: I really dislike the truck rumble and I don’t like the hum either.

The AirPods don’t know what the user feels most disturbed by, and they apparently can’t reduce all noises with max effectiveness at the same time.

Improvements I’d like to see

The AirPod Pro 2’s adaptive ANC has a lot of potential.

In loud environments, it is generally very effective. Sometimes, however, it misses the mark by quite a bit.

I’d prefer to have more control over the noise cancelling function. In particular for noise sensitive people, predictability is important.

In addition to the adaptive ANC, I’d like to see fixed ANC modes (at least two, such as max and low) in these earbuds.

Here is why:

• A max ANC mode could be more effective at reducing intermittent noises in a quieter environment.
• A noise cancelling mode offering moderate noise reduction could work for people who can’t tolerate strong, adaptive ANC. Such a mode could provide enough noise reduction for reducing stress without isolating the user.
• At times, I can feel how the ANC adapts in response to a noise source being “turned on;” the earbuds produce an “eardrum suck effect.” Walking around town, I am generally OK with this, but when I want to focus or meditate, I’d prefer not to experience such changes.
  Note: I don’t think there is a real pressure change but what counts is what the user perceives.

Perhaps a firmware upgrade could add fixed ANC modes, given the capabilities these earbuds have.   

Finally, while the AirPods Pro 2 have a powerful noise cancelling function, I would like to see more passive noise isolation against high frequency noise (see my chart above).

And, these earbuds should come with XL ear tips. Looking at reports on the Internet, quite a few people with large ears struggle with the L-size tips.

A case offering additional space for even larger ear tips would come in handy.