Is there a possibility to scale the x-axis of the splMeter Window?

Hey guys,

for a scintific thesis, I work on a project to analyse acoustic signals. I calculate much acoustic parameters and know i try to calculate the SPL from a .wav Data. I record it with a sample rate of 44.1kHz and i used the splMeter function to get a view on the SPL. My problem is the scale of the SPLWindow. I cant set it to x=0. Now the smallest x-value is about 28,8sec. So i miss the shape of 24 seconds from the SPL.

The yellow graph show the Lt- time weighted sound level (dB). The other graphs a not that important.

I also tried to search on MathWorks for other solutions but I cant find any. You can find the code i used below. The .wav data is also in the attachments to see.

Another short question: Is there another option to calculate the SPL from a .wav data?

Thanks for your help!<3

audFileName = '252_222oS.wav';

scope = timescope('SampleRate',44100,...

'TimeSpanSource','property',...

'YLimits',[20 110], 'AxesScaling','auto',...

'ChannelNames',...

{'LAF', 'LAeq', 'LApeak', 'LAmax'});

SPL = splMeter('TimeWeighting', 'Fast',...

'FrequencyWeighting', 'A-weighting',...

'SampleRate', 44100, ...

'TimeInterval',2,...

'CalibrationFactor',1);

x = audioread(audFileName);

[LAF,LAeq,LApeak,LAmax] = sm(x(:,1));

scope([LAF,LAeq,LApeak,LAmax])

Answer 1

[jibrahim]

Hi Bjorn,

I noticed that you set TimeSpanSource to true on the scope, but did not change the actual time span value. Maybe that's the issue?

audFileName = '252_222oS.wav';
[x,fs] = audioread(audFileName);

SPL = splMeter('TimeWeighting', 'Fast',...
    'FrequencyWeighting', 'A-weighting',...
    'SampleRate', fs, ...
    'TimeInterval',2,...
    'CalibrationFactor',1);

scope = timescope('SampleRate',fs,...
    'TimeSpanSource','property',...
    'TimeSpan',size(x,1)/fs,...
    'YLimits',[20 110], 'AxesScaling','auto',...
    'BufferLength',size(x,1)*4,...
    'ChannelNames',...
    {'LAF', 'LAeq', 'LApeak', 'LAmax'});


[LAF,LAeq,LApeak,LAmax] = SPL(x(:,1));
scope([LAF,LAeq,LApeak,LAmax])

[Justin]

hey was wondering, any idea how to obtain the L50 level from this data?