Warning: Unable to play audio because no audio outputs were found.

Hey, I'm trying to play an mp3 file on MATLAB, but it's giving me this error:

Warning: Unable to play audio because no audio outputs were found.

> In audiovideo.internal/audioplayerDesktop/hasNoAudioHardware (line 565)

In audiovideo.internal/audioplayerDesktop/play (line 228)

In audioplayer/play (line 349)

In sound (line 77)

This is my code:

[y,Fs] = audioread('Applause.mp3');
sound(y,Fs);

I'm not sure what I'm doing wrong...

[Charlie Ford]

I'm running a MATLAB instance on a server which has no audio hardware (and I'm OK with the lack of audio h/w).

I'd like to avoid the orange stack trace.

How can I instruct MATLAB to deal more gracefully with a "null audioplayer" due to absence of audio h/w ?

[Walter Roberson]

@Charlie Ford

Have you experimented with warning to turn the individual warning off? See lastwarn to figure out what the appropriate identifier for it is.

You might even want to go as far as to warning('') first to clear the last warning, then check lastwarn() afterwards to see if the warning was given, with the goal of skipping any appropriate steps in your code that will not work without audio.

Answer 1

[Vinai Datta Thatiparthi]

Hello Anthony,

This error could be the result of the path being modified, or the necessary libraries being removed to access the sound components on the computer. To fix this, in the command window, use -

restoredefaultpath
rehash toolboxcache
savepath

Further, evaluate if MATLAB is able to read the available outputs for audio on your PC using the function audiodevinfo. This results in a struct array containing all available & recognized audio inputs/outputs.

info = audiodevinfo

In case info returns an empty struct, it could be because of faulty drivers. Update all your drivers or disable devices one at a time and restart MATLAB and try 'audiodevinfo' to figure out if one or more devices has a possible faulty driver.

Instead, if info returns a struct with available outputs for audio (non-empty), you should be able to play the audio using audioplayer object. Additionally, if info has recognized multiple audio outputs, you can also use "device ID" to specify the output audio device.

Hope this helps!

[Van Cygnon Tango]

Hi Vinai,

I had the same problem as Anthony and it was cured thanks to your solution. You got my upvote!

[Mary Brown]

This did not work for me. I still get an error message. I'm trying to play an audio file from code listed in an textbook for a MATLAB class in Coursera. In the function window, this is the code I typed:

function play_tone(f)

Fs=8192;

t = 0:1/Fs:1;

tone=sin(f*2*pi*t);

sound(tone,Fs);

In the command window, I type play_tone(147)

I get the following error message below. How do I set the audio outputs?

Warning: Unable to play audio because no audio outputs were found. 
> In audiovideo.internal/audioplayerDesktop/hasNoAudioHardware (line 565)
In audiovideo.internal/audioplayerDesktop/initialize (line 354)
In audiovideo.internal.audioplayerDesktop (line 198)
In audioplayer (line 130)
In sound (line 74)
In play_tone (line 5) 
Warning: Unable to play audio because no audio outputs were found. 
> In audiovideo.internal/audioplayerDesktop/hasNoAudioHardware (line 565)
In audiovideo.internal/audioplayerDesktop/play (line 228)
In audioplayer/play (line 349)
In sound (line 77)
In play_tone (line 5) 

[Walter Roberson]

If you are using matlab online then audio can only be used with Chrome browser.

[沁禾 彭]

thanks a lot! Your answer helps me so much!

Answer 2

[Guilherme Vitor Santos]

estou com esse poblema matlab online

Error evaluating 'InitFcn' callback of Audio Device Writer block (mask) 'lllabtetecom/Audio Device Writer'.

Callback string is 'audioblkAudioDeviceIO(gcbh, 'initfcn');'

Caused by:

No audio input device detected

[Walter Roberson]

If you are using matlab online then audio can only be used with Chrome browser.

Answer 3

[Image Analyst]

This happens to me a lot. I have a PlaySoundFile() function that plays a sound file through the speakers. I'm using MATLAB desktop, not online. I have to do the restoredefaultpath to fix it. Then it's fixed for a while but something causes it to break again and I'll get the error message again

In PlaySoundFile (line 74)

Warning: Unable to play audio because no audio outputs were found.

> In audiovideo.internal/audioplayerDesktop/hasNoAudioHardware (line 565)

In audiovideo.internal/audioplayerDesktop/play (line 228)

In audioplayer/play (line 349)

In sound (line 77)

In PlaySoundFile (line 74)

I wish I could figure out what is causing it to break. I don't believe it's because I'm removing sound libraries. I do set the path to some folders in my startup.m file but that happens every time I start MATLAB and it works fine until some mysterious process causes it to break, so it's not adding things to the path that's causing it to break.

Answer 4

[Jonas]

anything new on this topic? can't make matlab to play sounds again, there are audio devices available, resetting/rehashing has not the effect i hoped to see. Only a matlab restart can resolve this for me, but i need to reset on runtime, e.g. if this issue comes up during use of a self created app

[Image Analyst]

Not that I've heard of. What version are you using? I'm using the R2022b pre-release and I don't think it's happened to me there yet, though I don't remember playing sound files there much. It certainly works after it's been open not long, as with the other versions. I'm not sure what happens to eventually break it.

[Jonas]

I am using 2022a release. I cannot reproduce the problem reliably, I have the feeling the problem occurs if no audio device is plugged in when starting matlab and it is plugged in later. Resetting the audiodevice list using audiodevreset() brings up the plugged in devices in the list, but I can't make Matlab play any sound, neither using soundsc(), nor with audioplayer, be it with or without explicit device ID

using any of the previous suggestions like

restoredefaultpath
rehash toolboxcache
savepath

does not make any difference for me

[Image Analyst]

That's good information. I'll check that next time. I'm not in a "broken" state now so everything works fine but if it fails, then I'm going to check

info = audiodevinfo;

[Image Analyst]

OK, it broke again. Here's what I see

> In audiovideo.internal/audioplayerDesktop/hasNoAudioHardware (line 565)

In audiovideo.internal/audioplayerDesktop/play (line 228)

In audioplayer/play (line 349)

In sound (line 77)

In PlaySoundFile (line 74)

>> info = audiodevinfo

info =

struct with fields:

input: [1×4 struct]

output: []

So it sees 4 input microphones, but none of the output speakers for the 4 audio systems (internal, headset, etc.).

[Jonas]

did you try audiodevreset() and looked into the information again?

[Image Analyst]

@Jonas, no because I restarted and it's working again. It's not currently broken (yet). That (audiodevreset) might be a faster way to fix it than restarting. I can try it. But we'd really like to know what happened to break it in the first place so we don't have to fix it.

Answer 5

[Miguel corona palacios]

buenas noches, yo tambien tengo ese mismo problema. tengo una laptop dell quizas unos 5-10 años vieja y si se escucha el sonido, pero con una nueva hp, me marca erro, que puediera ser_

Warning: Unable to play audio because no audio outputs were

found.

> In audiovideo.internal/audioplayerDesktop/hasNoAudioHardware (line 565)

In audiovideo.internal/audioplayerDesktop/initialize (line 354)

In audiovideo.internal.audioplayerDesktop (line 198)

In audioplayer (line 130)

In sound (line 74)

Warning: Unable to play audio because no audio outputs were

found.

> In audiovideo.internal/audioplayerDesktop/hasNoAudioHardware (line 565)

In audiovideo.internal/audioplayerDesktop/play (line 228)

In audioplayer/play (line 349)

In sound (line 77)