Combination of two signals with different sample rates

30 views (last 30 days)
I want to combine two signals with different sampling rate. I have have 2 sound signals, one (A) has telephone quality (Fs = 8Kz) and the other (B) music CD quality(Fs = 44.1 KHz). I want to add the music from file B to file A as a music investment (need someweakening). The duration of the result is equal to the longer of A and B.
How i can manage it??
Mathieu NOE
Mathieu NOE on 13 Jun 2022
Edited: Mathieu NOE on 13 Jun 2022
that depends if the signal sampled at 44.1 kHz should not be downsampled because it contains valuable info in the high frequency range ( 4 to 22 kHz)
beside that , upsampling does not create "noticable" / bad info's if it's done correctly :
  • for real time upsampling : insert zero elements AND then low pass filter (see for example : slidesSampling.dvi (
  • for non real time upsampling : you can do the same , or simply interpolation. A higher order interpolation will almost create zero artifacts / info in the "new" frequency range. You can try it , do the upsampling and make the fft of the upsampled signal vs the original signal. You will end up will a almost zero fft amplitude in the extended frequency range. BTW, interp1 does not require any toolbox.

Sign in to comment.

Answers (1)

Peter Perkins
Peter Perkins on 13 Jun 2022
Use a timetable, and call synchronize. synchronize uses interp1, but it may be that you particularly want to use the SP-oriented resample function instead:
ttHighFreq.yUpsampled = resample(ttLowFreq.y,...)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!