Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 8202

The processing of signals for the purpose of extracting a parameter or property embedded in a signal. Signal goes in and far fewer numbers come out.

6 votes

Feature extraction from spectrum to aid categorisation

First thing to mention is that you must have some kind of Machine Learning algorithm to perform your recognition. You might want to use the following - what's yours? Neural Networks (easy to impleme …
jojeck's user avatar
  • 11.2k
2 votes

Open debate: Protocol for signal analysis

Personally, when working with audio signals I use: File metadata and parameters (if there's a calibration associated with it, bit-depth, sampling frequency, etc.) Metrics, such as RMS/peak dBFS level …
jojeck's user avatar
  • 11.2k
1 vote

Playing sound in left and right speaker alternatively and storing output in array in matlab

If you want to play only one channel then you must set zeros at one of your matrix columns, i.e.: sound_L = sound_array; sound_L(:,2) = 0; sound_R = sound_array; sound_R(:,1) = 0; So your code bec …
jojeck's user avatar
  • 11.2k
52 votes
Accepted

Meaning of Hilbert Transform

One application of the Hilbert Transform is to obtain a so-called Analytic Signal. For signal $s(t)$, its Hilbert Transform $\hat{s}(t)$ is defined as a composition: $$s_A(t)=s(t)+j\hat{s}(t) $$ The …
jojeck's user avatar
  • 11.2k
1 vote
Accepted

How to add repeated beeps to sound created with a pause in between each beep in MATLAB

Any pause can be done by using vector/matrix concatenation. Let's say you want to make a signal with pause of length P after it, then do the following: P = 400; beep = [sound_array; zeros(P, 2)]; N …
jojeck's user avatar
  • 11.2k
1 vote
Accepted

How to store the signal in a variable and plot the signal in MATLAB

I suggest you to do something like (one plot with two curves): figure plot(sound_L(:,1), 'b'); % blue hold on; grid on; % prevent from redrawing and add grid\ plot(sound_R(:,2), 'r'); % red legend({' …
jojeck's user avatar
  • 11.2k
2 votes

How convert scal to frequency when use cwt in matlab

I think you should try MATLAB's scal2frq. You provide the vector of scales, wavelet name and optionally sampling period. This will return vector of pseudo frequencies. In your case that should be som …
jojeck's user avatar
  • 11.2k
6 votes

Time-frequency representation of sound signal using Matlab

I believe that this "color graph" you are looking for is a spectrogram (although it looks to me more like a scalogram, but you did not mentioned wavelets). Let me give you an example in MATLAB of obta …
jojeck's user avatar
  • 11.2k
5 votes
Accepted

How do I generate sound using MATLAB?

Something like that should do. Please keep in mind that this code can be further improved by windowing your signal, using decibel scale for spectrum, taking only first half of a spectrum, etc. This is …
jojeck's user avatar
  • 11.2k
3 votes
Accepted

Pre-emphasis filter design

I don't really understand what are you trying to achieve with vector B that has 6 elements. Pre-emphasis filter is defined as: $$y[n]=x[n]-\alpha x[n-1]$$ Where $\alpha$ is $0.97$ in your case. Yo …
jojeck's user avatar
  • 11.2k
1 vote
Accepted

Order analysis or order tracking

Well my friend, if you read the following B&K tutorial about the Order Tracking, then you should encounter so called Vold-Kalman Order Filtering. Personally I don't like it (rather prefer Chirp-Fourie …
jojeck's user avatar
  • 11.2k
6 votes
Accepted

Negative values of the FFT

The rfft function returns complex values ordered in specific way. In order to retrieve the amplitude of your DFT you must take the absolute value of it. Easiest way to do that is to call y_a = np.abs( …
jojeck's user avatar
  • 11.2k
2 votes

Baby Cry recognition robust against the distance

This question is very broad and it is not possible to give a very good answer without even knowing the internals of your system (the type of the network and features make a big difference). However, I …
jojeck's user avatar
  • 11.2k
5 votes

Processing Accelerometer Vibration Data With FFT

After taking a closer look at your results, here is what I think. Because you are playing back sinusoid through your speaker you are also observing it's properties. It has some significant harmoni …
jojeck's user avatar
  • 11.2k
1 vote
Accepted

Create a third octave spectrum from a time signal

Hate to answer this question, but it is a plotting issue, not the actual design problem. Basically, you don't have enough points at low frequencies cause they are spaced linearly and you are plotting …
jojeck's user avatar
  • 11.2k

15 30 50 per page