Visualizing a wav file

Hi everyone. I have a .rec file that contains 14 different signals. When i open the .rec file in R Studio, my target signal was at Number 8. Then, i converted the file from .rec to .wav file. Please,can someone help with how i can visualize the .wav file to see the list of the signals?

[Walter Roberson]

R Studio? As in the integrated development environment for the R programming language?

Are these .rec files "toppy" files, such as might be created by a PVR ?

It is possible to put in "cue " chunks into .wav file. MATLAB normally ignores those, but if we knew more about the conversion process we might be able to figure out whether "cue " chunks were inserted or not.

[Olalekan Adesina]

Thank you. I mean how to visualize in MatLab. Not on R studio

[Olalekan Adesina]

I just used app to convert the .rec file to wav.

[Walter Roberson]

What app did you use to convert the .rec file to wav ?

Are these .rec files "topfield" files, such as might be created by a PVR ? https://fileinfo.com/extension/rec

[Olalekan Adesina]

RecRecover App

[Olalekan Adesina]

.rec in edf format

[Olalekan Adesina]

It's only one .rec file.

When i visualized the .rec file in R, there are 14 signals combined together in the .rec file. before i converted the .rec to .wav using the "RecRecover app"

[Walter Roberson]

It looks like RecRecover might be referring to https://www.wavosaur.com/forum/rec-recover-v-1-0-0-3-t1230.html ?

If a .rec file is edf format internally, we might perhaps be able to read it directly instead of trying to work with the converted .wav file.

Would it be possible for you to attach the .rec file? You would have to zip it and attach the .zip .

[Olalekan Adesina]

The file size is above 5MB

Answer 1

[Tanmay Das]

Hi,

To my understanding, you are facing issues in reading .wav file in MATLAB. You can use audioread function to read data from the file, and receive sampled data and a sample rate for that data. For visualization, the following code snippet can be referred:

[y,fs] = audioread(filename);
dt = 1/fs;
t = 0:dt:(length(y)*dt)-dt;
plot(t,y); xlabel('Seconds'); ylabel('Amplitude');
figure
plot(psd(spectrum.periodogram,y,'Fs',fs,'NFFT',length(y)));

You can refer to audioread and periodogram documentations for further information.

[Walter Roberson]

no, the issue is that in the original rec file there are marked divisions between signals, and the user wants to be able to recover the divisions in the wav file.

This depends upon the conversion process having written information into the wav file about where the divisions are, such as if the wav file has had "cue " chunks written to it. audioread ignores "cue " chunks so you cannot use audioread to read any cue information.

At the moment we are not certain that the conversion process wrote any cue chunks at all.

One possibility that we have not explored yet is that perhaps there is silence between the 14 signals, in which case perhaps silence detection could be used to find the boundaries of the signals.

[Walter Roberson]

You should open a new Question for that, as it is not related to this one.

When you open the new question, you should indicate there how you can tell where the boundaries are between the categories for each participant. Also, since you are talking about "seconds", whoever responds to your new Question is going to need information about the recording frequency.