CS425FZ Audio & Speech Processing

CS425FZ (Audio & Speech Processing) Assignment 1 (value 20%)

Released date: Tuesday 26 th November 2024Due date: Sunday 15th December 2024 at 23:59This is an open-book, graded assignment. Please cite all references as comments in yoursubmissions. You cannot directly reuse a solution from online sources or AI. You must not engagewith another student, in person or electronically (via phone, social media, etc.), to secureassistance with this Assignment. If you do so (even for only one of the questions), you will receivean automatic failure (0%), and it will also be reported to the Executive Vice-Dean of MIEC and/orMaynooth University Plagiarism board. We will perform similarity checkson submittedassignments to check for collaborative efforts. The lecturer reserves the right to interview youabout your submission in special cases. It should be mentioned that the Turnitin tool provided inMoodle can detect AI-generated context.The first assignment is to use the programs in Java, processing, Python, or Octave/MATLAB toprepare a narrative on digital waveforms and spectral analysis using the FFT and the Spectrogramto demonstrate your knowledge of how they work. Make sure that each plot can clearly illustratethe shape of the waveform, i.e. if you have to zoom in to get this, do so. Athick coloured block isnot acceptable. The results from your plotting should be placed into a PowerPoint presentation,and along with the plot, a sound file should be inserted into the page (it should be imported asmp3 to save space). The documents should also show on the following slide to each plot theprogramming scripts to generate the wave and its graph. The graphs should have titles, labelledaxes and a caption in the document (e.g. Figure 1, Figure 2).

Waveforms

1. Generate and plot one example of the waveform of a sinusoid at a frequency, amplitude,and phase of your choice. Show the waveform from time t=0. Select the frequency of thesinewave from the set of musicalnoteshttps://homes.luddy.indiana.edu/donbyrd/Teach/MusicalPitchesTable.htmGenerate and plot an example of waveforms composed of sinusoids at harmonicallyrelated frequencies to create either a sawtooth wave, a square wave or a triangle wave.

3. Read in a wav file of an “effect”/natural sound and plot only 20 seconds of it.
4. Read in a wav file of a Speech utterance (it could be from the web or recorded by yourself)and plot it (approx. 2-5 seconds), put the text of the utterance in the title of the plot.Page 2 of 2

Fourier transform

5. Plot the magnitude of the Fourier transform (FFT) of a signal composed of more than onesinusoid of different frequencies and amplitudes using a rectangular window. Use an FFTlength of N=256 and then N=2048.

6. Plot the magnitude of the Fourier transform (FFT) of the same signal composed of morethan one sinusoid of different frequencies and amplitudes using a Hanning window. Use anFFT length of N=256 and then N=2048.

7. Record at least 1 second of you saying代写CS425FZ Audio & Speech Processing  any vowel sound using Audacity or an equivalentsoftware. Use the editor to retain only the steady portion of the vowel waveform. Plot thmagnitude of the Fourier transform of this, picking a suitable value for N (e.g. 256, 512,1024 2048) so that it is easy to identify at least two formant peaks form the spectrum.

Spectrogram

8. Plot the spectrogram of the speech waveform you used earlier for a short window N=256and a long window N=1024. Identify the voiced and unvoiced speech in the plot.

9. Plot the spectrogram of a sound effect that has distinctive frequency components, e.g. abird sound, a chainsaw, a car starting, clock strike. Pick an appropriate window length forthe frequency components to be clearly displayed. Make sure to mention the windowlength in the title of the plot

10. Plot the spectrogram of a short drum loop of your choice with N=256 and N=2048 to showthat the shorter window means a better time resolution, and thus, the points in time of thedrum hits are easier to discern. Point this out in the figure in its caption.