https://github.com/soundshader/soundshader.github.io/blob/master/acf-v2/README.md Skip to content Toggle navigation Sign up * Product + Actions Automate any workflow + Packages Host and manage packages + Security Find and fix vulnerabilities + Codespaces Instant dev environments + Copilot Write better code with AI + Code review Manage code changes + Issues Plan and track work + Discussions Collaborate outside of code + Explore + All features + Documentation + GitHub Skills + Blog * Solutions + By Plan + Enterprise + Teams + Compare all + By Solution + CI/CD & Automation + DevOps + DevSecOps + Case Studies + Customer Stories + Resources * Open Source + GitHub Sponsors Fund open source developers + The ReadME Project GitHub community articles + Repositories + Topics + Trending + Collections * Pricing [ ] * # In this repository All GitHub | Jump to | * No suggested jump to results * # In this repository All GitHub | Jump to | * # In this user All GitHub | Jump to | * # In this repository All GitHub | Jump to | Sign in Sign up {{ message }} soundshader / soundshader.github.io Public * Notifications * Fork 17 * Star 320 * Code * Issues 2 * Pull requests 0 * Actions * Projects 0 * Security * Insights More * Code * Issues * Pull requests * Actions * Projects * Security * Insights Permalink master Switch branches/tags [ ] Branches Tags Could not load branches Nothing to show {{ refName }} default View all branches Could not load tags Nothing to show {{ refName }} default View all tags Name already in use A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch? Cancel Create soundshader.github.io/acf-v2/README.md Go to file * Go to file T * Go to line L * * Copy path * Copy permalink This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. Cannot retrieve latest commit at this time. 0 contributors Users who have contributed to this file 21 lines (13 sloc) 1.82 KB Raw Blame Edit this file E Open in GitHub Desktop * Open with Desktop * View raw * * View blame Visual Morphology of Vowels Demo: soundshader.github.io/acf-v2 Images below are auto-correlation spectrograms of vowels. * Definition of auto-correlation: ACF(X)=FFT[abs(FFT(X))^2]. It splits input X into amp*cos(freq*t+phi) waves, drops phases phi and squares amplitudes amp. For this reason, ACF(X) is a symmetric function. * The ACF images below render abs(ACF(X))/max(abs(ACF(X))). The ACF values aren't squared and aren't log10-scaled. * Low frequencies and high frequencies are rendered with different colors by applying bandpass filters: FFT[BPF*abs(FFT(X))^2]. The low frequency ACF is rendered with color (12,3,1) and the high frequency ACF - with color (1,3,12). Oversaturation allows to reveal more details without resorting to log10-scaling (which doesn't look good). * Sample rate: 16 kHz. Frame size: 4096. The rule of thumb: frame size = 1/4 of sample rate. This means that one ACF frame captures 1/4 sec of sound, and the frames overlap heavily. * The waveform is padded with zeros at both ends, to avoid abrupt edges on ACF images. In complex sounds, different frequencies fade out at different pace, which gives the distinctive shape to their ACF images. Click on the image below to see its high-res version. [xs] Below are all the vowel sounds I could find on wikipedia. [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [1] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [2] [30] [3] [4] [5] [6] [7] [8] [9] 10/2022 [ ] Go Footer (c) 2022 GitHub, Inc. Footer navigation * Terms * Privacy * Security * Status * Docs * Contact GitHub * Pricing * API * Training * Blog * About You can't perform that action at this time. You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session.