Hardware echo cancellation does not work on many devices

[equaeghe]

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
• This isn't a feature request or a discussion topic

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This is a revival of issue #6241. The posts there contain valuable information that cannot concisely be copied here. To deal with this issue, a whitelist was in place initially, which worked in the sense that only known ‘good’ devices would use built-in echo cancellation. Afterwards a switch was made to a blacklist, which was however not updated, leaving many people with non-usable call functionality.

I suggest others experiencing this issue to wait with commenting until the developers have indicated what info they need. The material in issue #6241 should give them a good starting point.

Bug description

Echo cancellation does not work on multiple devices and for various Android versions.
For example, my Samsung GT-I9192 Galaxy S4 Mini Duos (serranodsxx) on Android 7.1.2 (LineageOS) is affected.

Steps to reproduce

• call someone with Signal, using with affected device/OS (other party's device/OS seems irrelevant)
• have conversation

Actual result: Other party hears disturbing echo
Expected result: Other party does not hear disturbing echo

Depending on the device, the results vary when using headphones or not. On my device, the echo becomes worse when using headphones, so in a situation where the echo cannot be caused by sound being captured by my microphone. (My guess is that the echo cancellation functionality actually adds the echo.) For others, the echo disappears in this situation.

Suggested potential workarounds until the root cause can be addressed are to update the blacklist, to include an ‘advanced’ option that switches hardware echo cancellation on or off, or to disable echo cancellation when using headphones. A workaround is needed to avoid chasing users to Skype or so. (I managed to convince my family to switch to Signal and then the whitelist-to-blacklist move forced us back to Skype.)

Device info

Device: Samsung GT-I9192 Galaxy S4 Mini Duos (serranodsxx)
Android version: 7.1.2
Signal version: 4.17.5

Link to debug log

Not applicable.

[moxie0]

I'm happy to add devices to the blacklist, but only if we can confirm that they are a problem with stock Android.

[sluger]

👍 for my Moto G5SPlus on Android 7.1.1 Signal 4.18.3

[moxie0]

@sluger We'll need the ro.product.model string for that.

[sluger]

hi @moxie0, the ro.product.model is Moto G (5S) Plus

[ADepic]

This effects Oneplus 2 running lineage os too.

This is a deal breaker and needs to be sorted out

[schubtob]

@moxie0 Please add the Moto G4 (running stock) to the blacklist as well. I've had several people complain that they hear an echo during signal calls. Using headphones fixes this problem.

The ro.product.model string is "Moto G4".
Thanks!

[breversa]

Echo happens too on the Samsung Galaxy S III : ro.product.model=GT-I9300

[2-4601]

@breversa Which ROM are you running on that Samsung Galaxy S III?

[breversa]

The ROM is LineageOS for MicroG, taken from here : https://lineage.microg.org/

ROM download link :
https://download.lineage.microg.org/i9300/lineage-14.1-20180517-microG-i9300.zip

[ADepic]

I'm running that too - but I've had this problem since lineage plain version 14.1

[2-4601]

You should confirm that it's also an issue with stock Android, otherwise it won't be blacklisted as said in #7635 (comment).

[abooij]

I think there are many people not running stock Android. Personally, I'm not willing to delete my entire Android installation merely because one app is not functioning as desired. In #6241, there was a proposal to add a setting to the configuration screen. Is this something that can be considered as a remedy for such situations?

[breversa]

I agree with @abooij : I'd love to confirm the bug, but I have no practical way to do it, as I'm no longer running stock on any device.
Is there any other was to test that ?

[equaeghe]

@breversa @abooij I have asked on an xda forum for my device whether someone with stock could test it. So far without response. But that is one thing you can try. Adding a setting would be ideal for me as well, but I understand that this goes against the design ideas of the developers (setting explosion).

[breversa]

What about a "testing" build, then, to allow volunteers like us to test the behaviour with and without AEC, report here, then blacklist or not in the "consumer" build ?

[b0m0x]

The Xiaomi Mi A1 is also affected by non-working echo cancellation on stock.
ro.product.model=Mi A1

[letkan]

Please add Mi A2 Lite to the blacklist, I just tested the echo issue by replacing ro.product.model with Mi A1 and there was no more echo, finally I can use Signal for calls on this phone.

[3RMD]

Same thing with Xiaomi Mi A2. Tested on stock rom and various custom roms (conversation partner using iPhone).
Please add to blacklist.
Thanks in advance.

[JoaquimCSantos]

Xiaomi Mi A2 echo cancellation was resolved in the previous version. But with this last update it came back. Please add again to blacklist.
Thanks!

[ghost]

@greyson-signal Please also add ro.product.model = "Moto G4 Plus" to the HARDWARE_AEC_BLACKLIST. The "Moto G4" is on the list but the Moto G4 Plus is also affected with echos. Thank you!

[szabolcs-cs]

I have this problem with the Galaxy S4 (I9505) on Lineage OS. Could we get an option in Settings to switch to software echo cancellation manually?

[zjapske]

I have an galaxy s6 sm-920f, I tried multiple lineage os versions (14.1 16.0 and 17.1) all persons on the other side complained about hearing their own voice back with a small delay. I flashed my phone back to the stock rom call the echo is gone.

[Genis-Sage]

When I'm talking to my mom, I also hear my voice as an echo

my mother's phone: BQ Aquaris U Lite, stock android 7

[Salokyn]

Hi,

I get an echo (I ear my own voice) on a Oneplus 5 (ONEPLUS A5010, Oxygen OS 9.0.10) when calling a Oneplus 3 (ONEPLUS A3003, Oxygen OS 9.0.6).

It's fine on both sides when Oneplus 3 calls Oneplus 5.

[Lusofreak]

LG G7 THINQ ...

It's not a device issue if many devices are affected... it's a software issue, better coding/solution required...

[billie80]

Is it possible to add another device to the HARDWARE_AEC_BLACKLIST?
ro.product.model = SHIFT6mq

It is the newest device from a German manufacturer. They currently have problems with Hardware AEC. It would be great if it could be added to the list. Thank you very much in advance!

[Caerbannog]

[...] not all problem devices will be confirmed. [...]
With so many Android phones out there, having an advanced setting to turn off hardware echo cancellation and adding an FAQ entry [...]

Another solution could be to help inexperienced users to diagnose such issues and submit them.
Most VOIP solutions show a screen at random after calls for this purpose.

Something like a question "How was your call", with a thumb-up and a thumb-down buttons.
When the thumb-down is clicked, other questions can appear:

What was the problem?

• my correspondent heard an echo
• other

Click here to submit a report with your phone model

[jemaltz]

I believe that I am experiencing this issue with my Samsung s10e
ro.product.model: SM-G970F

The issue occurs when I am on speakerphone, and is generally triggered if an object/finger comes in close proximity to the noise cancelling microphone hole on the top of the phone

The issue remains until I switch speakerphone off

Thanks!

[JP2-S]

Echo from Samsung tab s5e SM-T720