VoiceOver, Audio Ducking, and Airplay

By Niall Gallagher, 30 April, 2015

Forum
iOS and iPadOS

Hi All.

I have just observed some strange behaviour involving VoiceOver, Audio Ducking, and Airplay which I thought might interest you all.
I have an Airport Express connected to a SONOS speaker, and I was streaming my iPhone's audio to said speaker using Airplay.

I suddenly noticed that the VoiceOver output was coming from my SONOS speaker instead of my iPhone, but the standard VoiceOver sounds were audible from the iPhone's speaker (clicks, beeps, rotor sounds, etc).

By complete chance, I noticed that the Audio Ducking setting in my VoiceOver rotor was turned off.
When Audio Ducking was turned on again, the VoiceOver output immediately returned to my iPhone, and my music came from the SONOS speaker.

So the moral of the story is, if you want VoiceOver output from your iPhone's speaker while using Airplay, ensure that Audio Ducking is turned on.

Note - Audio Ducking is turned on by default, and it is only present in the VoiceOver rotor if you opt to have it there in the rotor settings.
I had Audio Ducking included in my rotor settings as sometimes VoiceOver ducks my music when it is speaking, but the music does not return to normal volume after it is finished speaking.

I hope the above information is of benefit to someone.

Kind regards,

Niall

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Comments

By dvdmth on Saturday, April 25, 2015 - 02:28

I observed something similar when trying out AirPlay with my Airport Express. I think I know the reason why as well.

It was explained to me a while back that iOS has two audio channels, one for ringtones and alerts, and one for media. The media channel ducks whenever audio is played on the alert channel. This is the behavior normally observed by an iOS user, without VoiceOver.

I think the audio ducking toggle for VoiceOver is simply changing which audio channel VoiceOver speech is output on. If audio ducking is on, VoiceOver goes to the alerts channel, whereas if audio ducking is turned off, the speech is put on the media channel and therefore won't causing any ducking.

Since AirPlay redirects the media channel to the remote speakers while keeping the alert sounds on the device, the audio ducking setting will have the effect of controlling where the VoiceOver output is heard.

By Roxann Pollard on Saturday, April 25, 2015 - 02:28

After reading this post, I tried the suggestion about audio ducking. I use the Big Jambox from Jawbone. I already had audio ducking on and as expected, when I woke up my iPhone 5, the voice went through to the Jambox. I turned off Jambox and then turned audio ducking off and back on. I restarted the speaker and Voiceover still played through the speaker. I wonder if you can have Voiceover through the phone only if you are using an Apple speaker system but if using something else it still sends the Voiceover through to the speaker no matter the audio ducking setting?

By Niall Gallagher on Saturday, April 25, 2015 - 02:28

In reply to by Roxann Pollard

Hi Roxann,

Unfortunately, I was able to replicate your scenario with a UE Boom and Bose Mini Soundlink bluetooth speaker.
I suspect your conclusion is correct, i.e . VO and other audio output are only separated when using Apple Airplay devices.

Kind regards,

Niall

Hi Dvdmth,

This is very interesting.
Thank you so much for sharing this information.

Kind regards,

Niall

By dvdmth on Monday, May 25, 2015 - 02:28

AirPlay and Bluetooth are completely different technologies. There may be some confusion since Bluetooth speakers appear in the AirPlay menu in Control Center, but if you're using a Bluetooth speaker, you are not using AirPlay.

With Bluetooth, all sounds are redirected to the external speaker, including notifications, so VoiceOver will also be included. The only exception is for an alert sound such as the phone ringing, time expiring, etc. When those sounds play, the audio is taken off the Bluetooth device and moved to the internal speaker. This behavior makes sense when using Bluetooth headphones, but not so much with regular speakers.

Since AirPlay is designed for streaming to in-home speakers, not headphones, the behavior implemented by Apple is different.

By Roxann Pollard on Monday, May 25, 2015 - 02:28

Hello dvdmth:

Thanks for the clarification. I guess I didn't realize that I was actually using two different technologies. Your explanation makes sense to me. Perhaps Apple will change this in the future.

By david s on Monday, May 25, 2015 - 02:28

This is interesting. I am having the same conversation with another person about this. I don’t have a pair of Bluetooth speakers or Airplay speakers but I do have a pair of Starky Halo hearing aids.

The Halos uses BT 4.0 and Airplay. With audio ducking on or off, VO and all other sounds goes to the Halos with the exception of notifications. Ring tones, text msg alerts alarm, etc. are still routed to the phone speakers.

Now I know why. Thanks for the info.

By Brian Borowski on Monday, May 25, 2015 - 02:28

This was originally done this way, because when a person is using something like a Zeppelin Air and AirPlay, the VoiceOver audio was so delayed when being inserted into the regular music stream that it took more than a second after you touched an icon until the audio for it appeared in the audio stream that it was almost unusable. Apple changed it a couple years ago the next iteration after AirPlay was introduced to the world. After the change, I could use AirPlay with VoiceOver again. I am grateful that it works this way. It might be a good option to have with bluetooth, because it can be really annoying to have Voiceover things blasting away on top of the music when you are listening, but on the other hand, it is nice to have the VO over the bluetooth speaker when you are walking around with one and listening to whatever one is listening to.

By Luke on Friday, September 25, 2015 - 02:28

I just recently discovered this trick as well and it is great) if we're entertaining guests at our house and I put music on via Airplay, I don't need VoiceOver jabbering away over our surround system, lol. As another user mentioned, it would be great if Apple made audio ducking work this same way for Bluetooth as well