Error using audioread function in MATLAB. It gives error while using .wav or .mp3.

>> [y,Fs] = audioread('C:\Users\sat33\Documents\MATLAB\audio1.wav')
*** audioread: problem reading C:\Users\sat33\Documents\MATLAB\audio1.wav - returning empty waveform

y =

     []


Fs =

     0

[Walter Roberson]

Which MATAB release are you using, and which operating system? You appear to be using some Windows version but I am not sure which.

[Satwik Dutta]

Hi Walter,

I am using MATLAB 2018b & Windows 10 OS.

I am able to run audioinfo(), just incase it helps-

>> info = audioinfo('audio1.wav')

info = 

  struct with fields:

             Filename: 'C:\Users\sat33\Documents\MATLAB\audio1.wav'
    CompressionMethod: 'Uncompressed'
          NumChannels: 1
           SampleRate: 8000
         TotalSamples: 14522333
             Duration: 1.8153e+03
                Title: '20Label'
              Comment: []
               Artist: []
        BitsPerSample: 16

[Walter Roberson]

Can you attach the .wav file for us to test?

Also check in case there are permission problems with the file.

Answer 1

[Astha Singh]

Hello Satwik,

This error might be the result of a third-party "audioread" function available on the internet, which is possibly shadowing the built-in MATLAB "audioread" function.

Verify you are using the built-in “audioread” function by executing the following line in the MATLAB Command Window:

>> which('audioread', '-all')

The only path displayed should be:

matlabroot\toolbox\matlab\audiovideo\audioread.m

Note that "matlabroot" in the path shown above will be replaced by the path of the folder where MATLAB is installed in your system.

If more than one path is displayed, a third-party function is taking precedence over the built-in "audioread" function.

If you want to return to using the built-in function, you must remove the third-party function from your MATLAB search path by executing the following lines in the Command Window:

>> rmpath(fileparts(which('audioread')))
>> savepath

[Satwik Dutta]

Thank you so much Astha. This was exactly the case.

[Alejandro Gonzalez]

After performing this action I get this error : Undefined function or variable 'audioread'. Help me! please.

[Walter Roberson]

@Alejandro Gonzalez

You would only do that rmpath() if you had a third-party audioread.m .

That said, audioread() was introduced in R2012b, so if you are using a version older than that, we would need to know your version in order to advise you what to use.

[Alejandro Gonzalez]

Thanks for answering. The version I use is R2016a

[Alejandro Gonzalez]

In fact other functions like: audiorecorder, wavread, wayplay, etc... also don't work come out as undefined

[Walter Roberson]

I suspect that you messed up your MATLAB path. Try using

restoredefaultpath
rehash toolboxcache
savepath

[Alejandro Gonzalez]

when i run the code audioread

it gives me this error

Error using audioread (line 135)
Error: File: Channel.m Line: 352 Column: 17
Unexpected MATLAB expression.

[Walter Roberson]

@Alejandro Gonzalez

Which MATLAB release are you using?

In current versions, audioread() line 135 has nothing to do with channel, work, but at about line 168 there is a call to asyncio.Channel . It is plausible that in a sufficiently early release that call might have been line 135.

[Alejandro Gonzalez]

The version of matlab that I use is shown here:

>> ver
----------------------------------------------------------------------------------------------------
MATLAB Version: 9.0.0.341360 (R2016a)
MATLAB License Number: *****
Operating System: Microsoft Windows 10 Home Version 10.0 (Build 18362)
Java Version: Java 1.7.0_60-b19 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
----------------------------------------------------------------------------------------------------
MATLAB                                                Version 9.0         (R2016a)
Simulink                                              Version 8.7         (R2016a)
Aerospace Blockset                                    Version 3.17        (R2016a)
Aerospace Toolbox                                     Version 2.17        (R2016a)
Antenna Toolbox                                       Version 2.0         (R2016a)
Audio System Toolbox                                  Version 1.0         (R2016a)
Bioinformatics Toolbox                                Version 4.6         (R2016a)
Communications System Toolbox                         Version 6.2         (R2016a)
Computer Vision System Toolbox                        Version 7.1         (R2016a)
Curve Fitting Toolbox                                 Version 3.5.3       (R2016a)
DO Qualification Kit                                  Version 3.1         (R2016a)
DSP System Toolbox                                    Version 9.2         (R2016a)
Data Acquisition Toolbox                              Version 3.9         (R2016a)
Database Toolbox                                      Version 6.1         (R2016a)
Datafeed Toolbox                                      Version 5.3         (R2016a)
Econometrics Toolbox                                  Version 3.4         (R2016a)
Embedded Coder                                        Version 6.10        (R2016a)
Filter Design HDL Coder                               Version 3.0         (R2016a)
Financial Instruments Toolbox                         Version 2.3         (R2016a)
Financial Toolbox                                     Version 5.7         (R2016a)
Fixed-Point Designer                                  Version 5.2         (R2016a)
Fuzzy Logic Toolbox                                   Version 2.2.23      (R2016a)
Global Optimization Toolbox                           Version 3.4         (R2016a)
HDL Coder                                             Version 3.8         (R2016a)
HDL Verifier                                          Version 5.0         (R2016a)
IEC Certification Kit                                 Version 3.7         (R2016a)
Image Acquisition Toolbox                             Version 5.0         (R2016a)
Image Processing Toolbox                              Version 9.4         (R2016a)
Instrument Control Toolbox                            Version 3.9         (R2016a)
LTE System Toolbox                                    Version 2.2         (R2016a)
MATLAB Coder                                          Version 3.1         (R2016a)
MATLAB Compiler                                       Version 6.2         (R2016a)
MATLAB Compiler SDK                                   Version 6.2         (R2016a)
MATLAB Distributed Computing Server                   Version 6.8         (R2016a)
MATLAB Report Generator                               Version 5.0         (R2016a)
Mapping Toolbox                                       Version 4.3         (R2016a)
Model Predictive Control Toolbox                      Version 5.2         (R2016a)
Model-Based Calibration Toolbox                       Version 5.1         (R2016a)
Neural Network Toolbox                                Version 9.0         (R2016a)
OPC Toolbox                                           Version 4.0.1       (R2016a)
Optimization Toolbox                                  Version 7.4         (R2016a)
Parallel Computing Toolbox                            Version 6.8         (R2016a)
Partial Differential Equation Toolbox                 Version 2.2         (R2016a)
Phased Array System Toolbox                           Version 3.2         (R2016a)
Polyspace Bug Finder                                  Version 2.1         (R2016a)
Polyspace Code Prover                                 Version 9.5         (R2016a)
RF Toolbox                                            Version 3.0         (R2016a)
Robotics System Toolbox                               Version 1.2         (R2016a)
Robust Control Toolbox                                Version 6.1         (R2016a)
Signal Processing Toolbox                             Version 7.2         (R2016a)
SimBiology                                            Version 5.4         (R2016a)
SimEvents                                             Version 5.0         (R2016a)
SimRF                                                 Version 5.0         (R2016a)
Simscape                                              Version 4.0         (R2016a)
Simscape Driveline                                    Version 2.10        (R2016a)
Simscape Electronics                                  Version 2.9         (R2016a)
Simscape Fluids                                       Version 2.0         (R2016a)
Simscape Multibody                                    Version 4.8         (R2016a)
Simscape Power Systems                                Version 6.5         (R2016a)
Simulink 3D Animation                                 Version 7.5         (R2016a)
Simulink Code Inspector                               Version 2.5         (R2016a)
Simulink Coder                                        Version 8.10        (R2016a)
Simulink Control Design                               Version 4.3         (R2016a)
Simulink Design Optimization                          Version 3.0         (R2016a)
Simulink Design Verifier                              Version 3.1         (R2016a)
Simulink Desktop Real-Time                            Version 5.2         (R2016a)
Simulink PLC Coder                                    Version 2.1         (R2016a)
Simulink Real-Time                                    Version 6.4         (R2016a)
Simulink Report Generator                             Version 5.0         (R2016a)
Simulink Test                                         Version 2.0         (R2016a)
Simulink Verification and Validation                  Version 3.11        (R2016a)
Spreadsheet Link                                      Version 3.2.5       (R2016a)
Stateflow                                             Version 8.7         (R2016a)
Statistics and Machine Learning Toolbox               Version 10.2        (R2016a)
Symbolic Math Toolbox                                 Version 7.0         (R2016a)
System Identification Toolbox                         Version 9.4         (R2016a)
Trading Toolbox                                       Version 3.0         (R2016a)
Vehicle Network Toolbox                               Version 3.1         (R2016a)
Vision HDL Toolbox                                    Version 1.2         (R2016a)
WLAN System Toolbox                                   Version 1.1         (R2016a)
Wavelet Toolbox                                       Version 4.16        (R2016a)

[Alejandro Gonzalez]

Help me! please

[Walter Roberson]

I had a look at the R2016a code... and I think you need to reinstall MATLAB itself (but not the toolboxes)

Around line 95 of your version is the code

    channel = asyncio.Channel( ...
        readPlugin,...
        PluginManager.getInstance.MLConverter, ...
        options, [0, 0]);

and synchio.Channel has its implementation at

toolbox/shared/asynciolib/+asyncio/Channel.m

Notice the + in the directory name: this is a "package" and when you call upon asycio.Channel() that way, it is restricted to finding the Channel.m that is inside the +asyncio folder. In particular, it would not be enough for you to happen to have a Channel.m of your own hanging around. To get the "wrong" Channel.m accidentally, you would have had to have an extra +asyncio folder hanging around -- not impossible, but pretty unlikely. It is more likely that somehow toolbox/shared/asynciolib/+asyncio/Channel.m got corrupted.

You could try using

    restoredefaultpath; rehash toolboxcache

and see if that solves the problem... I don't think it will, but it is worth the brief test (at lot faster to test that than to reinstall MATLAB itself.)

[Alejandro Gonzalez]

Do the test with the command but the error continues and indeed if the folder is found: toolbox/shared/asynciolib/+asyncio/Channel.m at that address, on line 95 of audioread. Channel.m not found.

% Create Channel object
    channel = asyncio.Channel( ...
        readPlugin,...
        PluginManager.getInstance.MLConverter, ...
        options, [0, 0]);

[Walter Roberson]

Sounds like the Channel.m file at that location is corrupt. If you have backups you could try restoring the file, but otherwise you will need to reinstall matlab itself.

[SAI BHARATH R]

walter, i have similar error but im using r2021b and uninstall also not happening

[Walter Roberson]

Please post a complete copy of the error message that you received. The details of line numbers are important for this purpose

[hanin t]

how if 'audioread' not found? how to fix it?

[Walter Roberson]

@hanin t

audioread was added to basic MATLAB (no toolbox needed) in R2012b.

If audioread() cannot be found in your system, there are several possibilities:

• you might be using R2012a or earlier; or
• your MATLAB installation might be corrupt or your MATLAB path might have removed some important paths. If either of these are true you are probably going to end up re-installing MATLAB; or
• perhaps what you are passing to audioread() is not a string or character vector (or numeric value, or cell array) and is instead a class object, and the real complaint is not about audioread() not being found but rather saying no method audioread for that particular class. However, when I tested this, I was not able to get such an error: the way audioread() is designed it should be found on the path for any class (and then when called, audioread() checks whether the input is valid)