Speech Feature Extraction
Last edited: August 8, 2025take audio
calculate Mel Scale representation
apply a series of Filter Banks which attenuates the input to highlight groups of frequencies

we then run a discrete-cosine transform to obtain MFCCs, because much of the output results will still correlate with each other
Speech Processing Index
Last edited: August 8, 2025Group Meetings
spinal tap
Last edited: August 8, 2025A spinal tap is a medical procedure whereby cerebralspinal fluid is collected by puncturing the lumbar; used to diagnose problems where biomakers from the brain are needed.
stability (ODEs)
Last edited: August 8, 2025A stationary point of an ODE is considered “stable” if, at the stationary point \(y=c\), the function with initial condition.
If you start near a stationary point, the function will either diverge \(t\to \infty\) to that stationary point, or converge to a stationary point. Whether the functions done that makes it “stable”/“unstable”.
For an autonomous ODEs \(y’(t) = f(y(t))\), suppose \(y(t) = c\) is a stationary solutiona:
- \(c\) is stable (i.e. \(t\to \infty, y \to c\) for \(y_0 \approx c\)) if the graph of \(f\) near \(c\) crosses from positive to negative; that is, when \(f’( c) < 0\)
- \(c\) is unstable (i.e. \(t\to -\infty, y \to c\) for \(y_0 \approx c\)) if the graph of \(f\) near \(c\) crosses from negative to positive; that is, when \(f’(t) > 0\)
- \(c\) is semi-stable (i.e. stable on one side, unstable on the other) if the graph of \(f\) near \(c\) has the same sign on both sides; meaning \(f’( c) = 0\) and \(f’’( c)\neq 0\)
- if \(f’( c) = 0\) and \(f’’( c) \neq 0\), we are sad and should investigate more
away from zeros, the concavity of \(y(t)\) could be checked for \(f f’\). when its positive, \(y(t)\) is concave up; when its negative \(y(t)\) is concave down.
