Recorded audio is not playing in most phone devices

Special Interest Groups Audio Processing
1

Hi, here’s my situation.

I am recording audio using audacity and a USB plug and use MIC in my laptop.
I can play the recorded file normally on my laptop.
When I export this recorded file as mp3, and send this mp3 file as email attachment to my parents to test on phones, the recorded audio is not playing at all. All I hear is insect like buzzing sound.
This is happening on android and iphones both. When converting to mono via audacity > Track menu > Mix > stereo to mono, then the sound stops playing even on my laptop, and is also not playing on phones.
I tried loudnum with audacity, tried normalize, and still the result is the same. The file is playing on the phone, but there is no sound, just an insect like buzzing.
I am totally lost here about what to do or how to fix this issue.

Any help is deeply appreciated.
I don’t know how to attach the mp3 file here in the forums. I have uploaded the file here:
tbrjar(dot)com/audio_test/normal.mp3

Thanks

2

You already had a post about this.

I’ll bet you are using a microphone with an XLR connector with some kind of USB converter which does not have a XLR connection, and another adapter in-between.

If I’m guessing correctly, you need a different USB interface with a proper-matching (balanced) XLR input, or you can use a “computer mic”.

Converting to mono will ONLY work if you kill one of the out-of-phase channels first. The regular stereo-to-mono conversion is the same thing that’s happening on the phone.

Mixing is done by summation (addition). If the left & right are identical but inverted relative to each other you are “adding a negative”, which is subtraction, and you are left with nothing.

1 Like
3

Hi @DVDdoug I recorded a different file using the new mic I bought, that is why I started a new post.
You are right, the mic I bought came with a pin jack, I don’t know what its called, 3.5 jack I suppose. I don’t have that port working in my laptop, So I plugged it in using a USB connecter.
Are you saying that I must use a proper USB device instead, with no connecters in between? Will that work fine?

Also, where can I make a feature request for audacity. I have 2 requests:

  1. Audacity to allow single channel mono recording, ability to switch between mono/stereo from a menu option. The recorded mono if needed can then be converted to stereo (with another option not by default).
  2. A screen reader friendly way to delete the left or right track from the by default stereo recording. Basically an option in any of the menus will be fine, like in the TRACK menu, I see there is an ADD option in TRACK menu already, a DELETE option can be added there which removes either left or right track from the stereo recording. I can easily access menu options in audacity using my screen reading software.
    This is the whole reason I love using audacity, it works just fine with my screen reader. I don’t have to mouse click on graphical buttons to do most of the stuff. I can simply hit “R” key to start recording and hit “Spacebar” to stop.
    Can audacity developers add these features?
    Oh one more feature. In noise removal we have to select a section of the audio, matching parts get removed from the rest of the audio. Can audacity select a default 100 milliseconds of clip from the starting of the recorded audio? Noise is generally right there in the beginning when the person had not started talking… Right now I cannot select because I think it needs mouse clicks. But if something is selected by default, then I can hit the other buttons using my screen reader to continue the rest of the process.
    Thanks
4

What’s the microphone?

Koz

1 Like
5

It’s Noise Reduction. Too many people insisted on making it remove the noise to zero.

It won’t do that.

You missed one. You can’t use Noise Reduction in a Macro or automatic collection of tools because of the two-step process.

There was a discussion a short time ago about how to automatically derive a useful Noise Profile from the production or show without the drag-select step.

There is no good method. That beginning or ending thing was suggested several times. I had my hopes pinned on an algorithmic analysis of the whole show similar to the way Zoom does it. That would be no.
`

You should know that Noise Reduction accepts the results of a Profile selection and hangs onto it until the sun cools off (or you turn off Audacity). So you might only have to do the profile step once for a show with similar shots and scenes. That does work.

You can drag-select your noise sample and export it as a stand-alone sound file. Open the file on the timeline and select it. Effect > Noise Reduction > Profile … and I think it accepts it.

Koz

1 Like
6

Hi @kozikowski Thanks for helping.

The microphone is this one: (link from amazon)
amazon(dot)in/HUMBLE-Dynamic-Recording-Microphone-SmartPhones/dp/B08HD7JQHX/
It’s not a high quality one, but I didn’t need something high quality. I only needed something that will not mess up the left/right channels. I thought this one will do. it didn’t…
It didn’t connect with my laptop via the jack, so I used a USB connector in between.

I will try your method for noise reduction, opening the standalone file and using it as profile.
I know how to use ffmpeg also, in case audacity is also using it for noise reduction, I can put the commands in a batch file directly and run them via command line. Is there a way?

7

I may need to wait for the Starbucks to kick in. Your microphone application combines every odd/magic condition.

An XLR microphone, in general, produces a good quality voice signal and sends it down a cable as two signals plus a shield—usually braided—all underneath a rubber cover.


The shield is connected to pin 1. The voice goes down pin 2 and an upside down copy of the voice goes down pin 3 as a protective signal.

A sound mixer, preamp, recorder, or XLR adapter “knows” about pins 2 and 3. They know that any difference between 2 and 3 is the show and must be protected. Anything that appears the same on 2 and 3 is trash and must be rejected.

Combine all that with a “Dynamic” or moving coil microphone which is almost impossible to overload by yelling and that gives you the rock band performance on the stage 50 feet (15M) away from the sound mixer.


I know that’s a Shure Brothers ad, but it’s really well done.

Scene shifts to your microphone. As near as I can tell, that complicated 3.5mm plug is expecting Left Headphone Sound on tip, Right Headphone Sound on the next ring back, then the Microphone Sound followed by the overall shield.

All these are “right side up.” This is the connection service for a stereo headset with two earphones and a single microphone plugged into your laptop This would be for gaming, Skype, Zoom, or communications. No rock bands, no stage, and no sound mixer.

Getting between those services is the trick.

As DVDDoug above, your current adapter produces a Left and Right show with the two sounds reversed to each other. This gives you the magic of the people listening in stereo (big sound system, headphones) hearing you maybe slightly oddly, but the people listening in mono (phone) hearing nothing. It is guaranteed that your valuable client will be the one with no sound.

Isn’t this fun?

This is close to what I did, but my adapter isn’t made any more and I had (still have) a stand-alone microphone, not a headset connection with everything in one like you have.

USBHeadsetAdapter_2024-07-01

Screen Shot 2024-07-01 at 6.00.35 AM
Screen Shot 2024-07-01 at 6.00.35 AM1149×503 176 KB

I’m not sure I know of a solution for this.
`

It does, but not the way you (or most people) want. Audacity will record a single microphone as “Left” in a stereo pair. This is the process with the least damage to the sound. Record in Stereo, convert to Two-Channel Mono and delete the blank track.

Left-Only_2024-07-01

Audacity will actually record in mono, but it leaves room for a stereo to mono conversion by dividing the sound by two. You get a single track, but it’s half the volume and twice the noise.

Koz

1 Like
8

Hi @kozikowski I am starting to understand this somewhat now. Till now I used to think that the ring on the jack is to make sure it fits properly, like a key… LOL I had no idea it had three parts like how you explained it. That was a very good explanation. Thanks for that.
Anyways, I have ordered a standalone recording device, like a dictaphone with its own storage. It will record and I will only need to transfer the recorded wav to my laptop.
I think this should work.
Thanks

9

That’s how I do it. Be sure you don’t buy a “Voice Recorder” which forces you to save the work in MP3. MP3 damages the sound every time you open one for editing and you can’t stop it. Never do production in MP3.

The H1n will save in WAV format.

H1nStudioConfig_1467
H1nStudioConfig_1467990×1000 278 KB

That’s an H1n Zoom stand-alone stereo sound recorder in “studio” configuration. Those are “studio” paper towels and a “studio” furniture moving blanket.

The other way to do that also produces good quality sound, but without the headphones. This is an iPhone SE and Lossless Voice Memo.

CatskillFarmsStudio-2_1778
CatskillFarmsStudio-2_17781000×791 232 KB

The only other shortcoming to this method is getting the track into the computer for editing. I know I’m supposed to use “Air Drop” or interconnect cable, but the last test I emailed to myself (Desperation Method). That cable is for battery charging.

That’s Pressure Zone Configuration. That’s not an accident with blue painter’s tape. I have a very quiet, echo-free office and that doubles the high quality voice volume for free and halves the electronic noise. Of course, I can’t drop things on the desk during recording.

Koz

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10

Hi @kozikowski Thanks for the suggestions. The one I have ordered saves it in wav format, and it has a USB port in the recorder which I can connect to my laptop to transfer files. You mentioned not to use mp3 files in production. Does this mean I should not use mp3 files in the videos I am making for youtube? I noticed that youtube uses AAC files in its videos.
The wav files the standalone recorder will give, should I encode them as AAC while making videos?
Thanks

11

There is a caution with that, too. I bet the recorder has a “real time” feature where you can record directly and in real time to the computer down the cable. Do Not Do That!

Direct recording puts you at the mercy of the thousands of apps, programs, settings, and configurations that think it’s a command from the angels to “help you” with your sound. Many forum postings are from people trying to remove all that help.

It might also be possible to get battery down that cable so you don’t have to replace your built-in batteries as often. That’s fuzzy. Battery from the computer can be noisy if you have messy or unstable wall power.

Koz

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12

Live recordings should be saved (exported) as WAV against the time that something happens in the editing or publication and you have to redo it.

The client may have special needs. ACX wants you to produce 192-Constant Quality MP3 files for audiobook submission. Mono is good, but they will accept stereo as long as the whole book is like that.

I don’t know what YouTube likes. That’s your research project. There is also the question of loudness. Music has its Loudness Wars where the object is to be louder (and thus more desirable) than the music around you. How to measure your loudness comes up. Audiobooks use the older RMS values. It’s pretty simple. How much heat can the sound make? That’s it. That’s RMS. There’s an RMS value for your wall power.

Newer services use LUFS. Loudness, K-weighted, relative to full scale ( LKFS). That one pays attention to the sensitivity of your ear. Two extreme examples: Earthquakes don’t make a lot of noise, but they can push the bookcase over and break windows. Kids are adorable, aren’t they? Try ignoring one screaming on a jet.

The kid is screaming at tones your ear is really good at. The quake, not so much.

Effect > Loudness Equalization can work in different standards.

Screen Shot 2024-07-01 at 10.41.19 AM

Koz

1 Like
13

There’s a Hollywood joke about earthquakes. The sound people can’t record one, and moving furniture around is expensive and hard to coordinate, so we use a wine glass. Zoom into the wine rippling in the glass just as the hero says: “Is that a quake?”

No, it’s probably a robust Shiraz.

Koz

1 Like
14

You bought a TRRS microphone. Your cellphone may need a TRS microphone (although that is unlikely).

15

That’s Tip, Ring, Ring, and Sleeve.

Koz

16

Hi @kozikowski Many thanks for all these suggestions. I don’t think my new recorder has the feature of direct recording to laptop. I haven’t received it yet. If that feature is there, I won’t use it now. Many thanks for this help all the members. I really learned a lot.
If you and @DVDdoug would not have caught the problem, I would have never in my life figured out the left/right cancelling problem on my own, never. Would have kept messing around with settings and this that trying to get the recorded audio to work. Would have ultimately given up.
I am deeply thankful to all the members of this forum who took the time to help me with this issue.
Best regards guys

17

I doubt this would help, but I am curious. If the audio is coming out silent, perhaps the Left and Right channel are already out of phase. That would explain why you also hear nothing when you mix stereo to mono. If, for some reason, the L and R tracks were polar opposites of each other, and you mix them together, they would cancel each other out. (You may not notice when played through your laptop because the speakers are likely far apart. The closer your speakers are, like on a cellphone, the better they will cancel out) Of course, you would be able to see that on the Audacity visual. The newly rendered mono track would have no or very little amplitude IF this is the case.

If I were you, I would perform this experiment. Split your stereo track into L and R: click the arrow drop down near the top left of you track and select “split stereo track.” Then select only one of those track and use the “invert” effect. Then select the arrow drop down from whichever of the two tracks is on top and select “make stereo track.” (As long as one track displays the stereo slider all the way to the left and the other track has the slider all the way to the right, you can always use “make stereo track” to combine tracks.) What does the final product sound and look like? Anything new?

Also, another way to get rid of noise is to use the effect “Noise Gate.” This one, you can use with a macro tool. Just set the threshold to a level above your noise and below your desired audio, and then set your “level reduction” all the way to the left (-100db). That way, any audio less than your chosen threshold will be reduced by -100db and basically inaudible. (This would not take the noise out of your desired audio, but it would remove the noise during parts that you want silent. If I’m being a perfectionist, it would hurt to use both Noise Gate AND Noise Reductions because too much Noise Reduction can start to alter the quality. Trust your ears.)

Good luck. :+1:

1 Like
18

Hi @SrgtSunflower Thanks for the reply. The problem got solved by using a standalone microphone which does the recording on a device of its own. Then I can transfer the file to my laptop and further process it with audacity or ffmpeg. I will try the noise gate feature you mentioned, sounds easy enough for me to use. Thanks

19

If you’ve recorded your iPhone screen and realized there’s no sound in the video, I totally get how frustrating that can be—especially if you were trying to capture something important like a tutorial or a funny moment in a game. But don’t worry, there are a few things you can try to make sure you get that sound back on your next recording.

First things first, let’s make sure the microphone is actually turned on for your screen recordings. This is a pretty common reason why your screen recordings might come out silent. When you’re about to start recording, press and hold the Screen Recording button in the Control Center (you know, that little circle icon). When you do this, a menu pops up with an option to turn the microphone on or off. Make sure the microphone icon is red, which means it’s on, before you start recording.

Now, if you’ve checked the microphone and it’s on, but you’re still not getting any sound, the issue could be with the type of audio you’re trying to record. iOS has some restrictions when it comes to capturing certain types of audio. For example, you won’t be able to record sound from phone calls or FaceTime, and some apps might restrict audio recording due to copyright or privacy reasons. If you’re trying to record something like a YouTube video or music from an app, the sound might not get picked up due to these restrictions.

Another thing to consider is where the sound is coming from. If you’re using headphones or a Bluetooth device, the sound might not be captured by the microphone. Try disconnecting any external audio devices and using the iPhone’s built-in speakers instead. This way, the microphone can pick up the sound more easily.

If you have problem persist after trying these solution, you can follow for more details instruction below.
https://thegeekpage.com/how-to-fix-no-sound-in-screen-record-on-iphone/