Vowel space in TiKz

vowel_space.tex

% !TEX encoding = UTF-8 Unicode
\documentclass[convert={density=400,size=500x500,outext=.png}]{standalone}
\usepackage{tikz}
\usetikzlibrary{backgrounds}

% \usepackage[active,tightpage,psfixbb]{preview}
\usepackage{tipa}
% \PreviewEnvironment{pgfpicture}
% \setlength\PreviewBorder{2pt}

\begin{document}
\begin{tikzpicture}[scale=.65, show background rectangle, 
  background rectangle/.style={fill=lightgray},
  color=white,
  help lines/.style={color=lightgray,line width=.2pt},
]

% \draw[help lines] (0,0) grid (25,20);



% arrows
\draw [-, ultra thick, rounded corners] (22,16.5) -- (22,3) -- (12,3) -- (3,17) -- (22,17) -- (22,16.5);
\draw [-, ultra thick, rounded corners] (12.5,17) -- (17,3);
\draw [-, ultra thick, rounded corners] (22,12.4) -- (6,12.4);
\draw [-, ultra thick, rounded corners] (22,7.8) -- (8.9,7.8);

% vowels
% FRONT
\draw [black!50, fill=gray!10] (2,17) circle [radius=0.5];
\node [font=\Large,blue] at (2,17) {\textipa{i}};
\draw [black!50, fill=gray!10] (4,17) circle [radius=0.5];
\node [font=\Large,blue] at (4,17) {\textipa{y}};
\draw [black, fill=gray!95] (3,17) circle [radius=0.15];


\draw [black!50, fill=gray!10] (6.9,15) circle [radius=0.5];
\node [font=\Large,blue] at (6.9,15) {\textipa{I}};
\draw [black!50, fill=gray!10] (8.9,15) circle [radius=0.5];
\node [font=\Large,blue] at (8.9,15) {\textipa{Y}};
\draw [black, fill=gray!95] (7.9,15) circle [radius=0.15];


\draw [black!50, fill=gray!10] (5,12.4) circle [radius=0.5];
\node [font=\Large,blue] at (5,12.4) {\textipa{e}};
\draw [black!50, fill=gray!10] (7,12.4) circle [radius=0.5];
\node [font=\Large,blue] at (7,12.4) {\textipa{\o}};
\draw [black, fill=gray!95] (6,12.4) circle [radius=0.15];

\draw [black!50, fill=gray!10] (7.9,7.8) circle [radius=0.5];
\node [font=\Large,blue] at (7.9,7.8) {\textipa{E}};
\draw [black!50, fill=gray!10] (9.9,7.8) circle [radius=0.5];
\node [font=\Large,blue] at (9.9,7.8) {\textipa{\oe}};
\draw [black, fill=gray!95] (8.9,7.8) circle [radius=0.15];


\draw [black!50, fill=gray!10] (9.32,5.6) circle [radius=0.5];
\node [font=\Large,blue] at (9.32,5.6) {\textipa{\ae}};
\draw [black, fill=gray!95] (10.32,5.6) circle [radius=0.15];


\draw [black!50, fill=gray!10] (11,3) circle [radius=0.5];
\node [font=\Large,blue] at (11,3) {\textipa{a}};
\draw [black!50, fill=gray!10] (13,3) circle [radius=0.5];
\node [font=\Large,blue] at (13,3) {\textipa{\OE}};
\draw [black, fill=gray!95] (12,3) circle [radius=0.15];

% CENTRAL
\draw [black!50, fill=gray!10] (11.5,17) circle [radius=0.5];
\node [font=\Large,blue] at (11.5,17) {\textipa{1}};
\draw [black!50, fill=gray!10] (13.5,17) circle [radius=0.5];
\node [font=\Large,blue] at (13.5,17) {\textipa{0}};
\draw [black, fill=gray!95] (12.5,17) circle [radius=0.15];

\draw [black!50, fill=gray!10] (13,12.4) circle [radius=0.5];
\node [font=\Large,blue] at (13,12.4) {\textipa{9}};
\draw [black!50, fill=gray!10] (15,12.4) circle [radius=0.5];
\node [font=\Large,blue] at (15,12.4) {\textipa{8}};
\draw [black, fill=gray!95] (14,12.4) circle [radius=0.15];


\draw [black!50, fill=gray!10] (14.65,10.1) circle [radius=0.5];
\node [font=\Large,blue] at (14.65,10.1) {\textipa{\textschwa}};


\draw [black!50, fill=gray!10] (14.45,7.8) circle [radius=0.5];
\node [font=\Large,blue] at (14.45,7.8) {\textipa{3}};
\draw [black!50, fill=gray!10] (16.45,7.8) circle [radius=0.5];
\node [font=\Large,blue] at (16.45,7.8) {\textipa{\textcloserevepsilon}};
\draw [black, fill=gray!95] (15.45,7.8) circle [radius=0.15];


\draw [black!50, fill=gray!10] (16.15,5.6) circle [radius=0.5];
\node [font=\Large,blue] at (16.15,5.6) {\textipa{5}};


\draw [black, fill=gray!95] (17,3) circle [radius=0.15];
% \draw [black!50, fill=gray!10] (17,3) circle [radius=0.5];
% \node [font=\Large,blue] at (17,3) {\textipa{a}};

% BACK

\draw [black!50, fill=gray!10] (21,17) circle [radius=0.5];
\node [font=\Large,blue] at (21,17) {\textipa{W}};
\draw [black!50, fill=gray!10] (23,17) circle [radius=0.5];
\node [font=\Large,blue] at (23,17) {\textipa{u}};
\draw [black, fill=gray!95] (22,17) circle [radius=0.15];


\draw [black!50, fill=gray!10] (20,15) circle [radius=0.5];
\node [font=\Large,blue] at (20,15) {\textipa{Y}};
\draw [black, fill=gray!95] (19,15) circle [radius=0.15];


\draw [black!50, fill=gray!10] (21,12.4) circle [radius=0.5];
\node [font=\Large,blue] at (21,12.4) {\textipa{7}};
\draw [black!50, fill=gray!10] (23,12.4) circle [radius=0.5];
\node [font=\Large,blue] at (23,12.4) {\textipa{o}};
\draw [black, fill=gray!95] (22,12.4) circle [radius=0.15];


\draw [black!50, fill=gray!10] (21,7.8) circle [radius=0.5];
\node [font=\Large,blue] at (21,7.8) {\textipa{2}};
\draw [black!50, fill=gray!10] (23,7.8) circle [radius=0.5];
\node [font=\Large,blue] at (23,7.8) {\textipa{O}};
\draw [black, fill=gray!95] (22,7.8) circle [radius=0.15];

\draw [black!50, fill=gray!10] (21.,3) circle [radius=0.5];
\node [font=\Large,blue] at (21,3) {\textipa{A}};
\draw [black!50, fill=gray!10] (23.,3) circle [radius=0.5];
\node [font=\Large,blue] at (23,3) {\textipa{6}};
\draw [black, fill=gray!95] (22,3) circle [radius=0.15];

\end{tikzpicture}
\end{document}