You probably don’t think about audio latency.
Audio latency is the difference in time between when your device plays a sound and you hear it. When I play audio from my iPhone to my car’s audio system via Bluetooth, it takes a second for the audio to stop playing after I press the pause button on my phone. That’s latency. Latency happens because it takes time to encode audio, send it across a wireless link, receive it on the other end, decode it, and play it back.
In a lot of cases, our devices can engineer out the latency. This happens every time you watch a video on an iPad or iPhone while using Bluetooth headphones. The system is actually sending you the audio in advance of the video so that when it plays back, it’s synced up. Unfortunately, that only works when you know in advance the content that’s going to be displayed.
I discovered Stephen Coyle’s post about AirPods latency yesterday via a Marco Arment tweet referring to a John Voorhees linkpost on MacStories. I mention the chain of events because Marco and John edit podcasts and are intently interested in the issue of audio latency. Coyle, meanwhile, makes a rhythm game called Tapt which also requires low latency:
The kinds of sounds for which this is a problem are those which are unpredictable. User-initiated sounds, which the platform has no way to know are coming, are the most commonly encountered example. Keyboard clicks or other UI sounds, accessibility features like VoiceOver, and game sound effects should be familiar as the kinds of sounds that often get mangled by audio latency. These sounds are a delight in a low latency context (for example, via the device speaker or wired earphones) but start to get clumsy and obstructive when delays are added. Obviously, when these sounds are nice-to-haves they can just be disabled (as I’ve done on everything with which I use wireless earphones), but when they’re vital accessibility features wireless earphones can substantially lower the user experience.
Here’s the good news: The second-generation AirPods have lower latency than the first-generation model, and the latency on the AirPods Pro are even lower. I’ve noticed this myself, but Coyle has quantified it. Apple is making great strides here.
But, as Marco Arment wrote:
For the last six months I’ve been editing The Incomparable exclusively on my iPad Pro and when I got the AirPods Pro I gave them a try, anticipating some improved latency.
My experience was exactly the same as Marco’s. I could use them, but every move I made was more sluggish. (Coyle refers to attempting to play piano in Logic Pro while wearing AirPods as “a deeply unsettling experience.”) I rapidly broke out my USB-to-headphone adapter and put on a pair of wired headphones to make my edits, and normalcy was restored.
I would love to use wireless headphones to edit audio. Maybe Apple will keep pushing latency down to the point where wireless headphones will be indistinguishable from wired. But for now, the only way I can efficiently edit podcasts is through wired headphones and speakers with minimal latency.