Speaker remains on after playback completes

[Robie Basak]

This might be a Media Hub bug - I'm not sure.

Steps to reproduce:

1. Start playing a podcast.
2. Switch to a different app.
3. Lock the screen.
4. Wait for the Podcast to finish.
5. Wait a bit longer.

Expected results:

No noise from speaker.

Actual results:

Soft white noise from speaker. It seems that some part of the audio subsystem is still switched on. I am concerned that this could be draining battery.

Workaround:

After the Podcast finishes, unlock the phone and switch back to the Podbird app. This causes the noise to stop.

Comments:

I noticed the same soft white noise continues a second or two after the phone plays any sound from any app, but then turns off. I presume there is some time out turning off some part of the audio subsystem. Presumably if there is a reason, it should happen even when the app causing the sound to play is not active.

[Robie Basak (racb)]

Oh, forgot to say:

bq Aquarus running image r21. Podbird version 0.5.

[Nekhelesh Ramananthan (nik90)]

Thanks for taking the time to report this bug in great detail. I am unable to reproduce this bug on N4 and BQ aquarius running image r21. Could you perhaps let me know how long the podcast should keep running in the background after which you can start to hear the soft noise? Also do you hear the soft white noise from the the speaker or on the headphone as well?

I am adding the media-hub project to this to get their opinion as well since Podbird uses standard QML widgets to play podcasts similar to other media apps. So I am curious to see what the difference is in Podbird to cause this issue.

[Robie Basak (racb)]

Hi Nekhelesh,

> Could you perhaps let me know how long the podcast should keep running in the background after which you can start to hear the soft noise?

It's immediate - it's audible as soon as the podcast finishes. The reason I said "wait a bit longer" was to give the sound an opportunity to stop. Maybe I should have made it clearer that the noise is very quiet?

Perhaps we first need to identify the noise I'm talking about. It doesn't just happen from listening to a podcast, and it may be more obvious to hear it for the first time when the phone is expected to be silent.

Another occasion the noise happens (I don't think this is a bug in itself) is if I go to a web page in the browser that is capable of audio even if I don't actually play the media. In this case I hear the noise start soon after entering the page (I suspect when things have loaded) and it continues for fifteen seconds before stopping (I timed it). Example page: http://m.bbc.co.uk/news/world-europe-32374005 - try entering this page by following the link from this Launchpad bug page on the phone while holding the speakers up to your ear in a quiet room (I only notice the noise at night). I hear a soft pop, then quiet white noise for fifteen seconds, and then the noise stops. You can use back and forward to try again - after pressing back wait fifteen seconds to make sure it is gone. Go forward again and you should hear the noise start as soon as the "play" button appears on the video.

Once you've identified the noise I'm talking about, you will hopefully be able to hear it at the end of a podcast also. It's more notable when it stops - so try seeking to near the end of a podcast, switching away from the Podbird, locking the phone and waiting for the podcast to finish. Then while listening unlock the phone and switch back to Podbird - the sound of the noise stopping may be more obvious.

The difference between my Browser case and my Podbird case is that in the Podbird case the noise carries on indefinitely, so the Browser case isn't really a battery drain, but the Podbird case could be, since I first noticed the noise an hour or two after a podcast finished.

I just tried reproducing on headphones. I can hear the noise start in the Browser, but it is so barely audible that I can only do this because I know when I'm expecting it. It isn't really loud enough for me to hear if the same thing happens in Podbird.

[Jim Hodapp (jhodapp)]

I can hear the background hissing noise that you're most likely referring to, however for me, it goes away after a second or two after podcast playback stops. So I can reproduce this either.

[Robie Basak (racb)]

@Jim

The hiss stops after I unlock the phone and switch back to Podbird. Can you confirm that you tried this after allowing a podcast to finish while the phone is on a different app and locked?

[Jim Hodapp (jhodapp)]

@Robie: good point, I did not lock the screen for that. Let me give that another try.

[Jim Hodapp (jhodapp)]

@Robie: ok, so yes when the screen is locked I can confirm still being able to hear the background hissing noise. This might be a pulseaudio issue as well, so adding that project to the report.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Morgan (z-admin-angels-gmail-com)]

Hello,

I confirm this bug. I often listen podcast (it's help me to fall in sleep).

The night I listen podcast and the morning I wake up and my batterie has been drained by ~ 20/30%.

It's very anoing !

[Michał Sawicz (saviq)]

I've just filed bug #1541156 as I don't think the one this was duped to is the same as my issue.