Uses of the pitch-scaled harmonic filter in speech processing by Philip Jackson * and Christine Shadle † *School of Electronic and Electrical Engineering, University of Birmingham †Department of Electronics and Computer Science, University of Southampton

Prologue Much Ado About Nothing (Act 2) Balthasar: “Note this before my notes: There’s not a note of mine that’s worth the noting.”

Pitch-scaled harmonic filter Developed to study turbulence noise during voicing Many potential speech applications: coding analysis perception recognition

Spectral smearing Effect of rectangular windowing

Spectral smearing Effect of Hann windowing

Minimising spectral smearing Influence of negative frequencies

Minimising spectral smearing Influence of higher harmonics

Interpolation: Harmonic filter: Decomposition

PSHF decomposition

Performance measure Change in Signal-to-Error Ratio: Synthesis: where

Evaluation - HNR periodic aperiodic

Evaluation (periodic) +10 dB

Evaluation (aperiodic) +10 dB

Time series for /ax-v:/

Short-time power for /ax-v:/

Power spectra for /v:/ F0F1F2F3

LPC spectra for /v:/ F0F1F2F3

MFCC spectra for /v:/ LPCMFCC F0F1F2F3F0F1F2F3

Power spectra for /zh:/ F2

Fricative spectra for /zh:/ F2

LPC spectra for /zh:/ MFCCLPC Z1

Summary Pitch-scaled harmonic filter: –Benefits of pitch scaling –Case for interpolation –Periodic + aperiodic for TD and FD –Evaluated on synthetic speech Applied to real data: –Time series –Power spectra –Short-time power –LPC –MFCC

Epilogue Much Ado About Nothing (Act 2) Balthasar: “Then sigh not so, but let them go, And be you blithe and bonny; Converting all your sounds of woe Into Hey nonny nonny [aka. HNNs].”