diff --git a/src/AnalysisChart.tsx b/src/AnalysisChart.tsx
index 7421282..faeff5e 100644
--- a/src/AnalysisChart.tsx
+++ b/src/AnalysisChart.tsx
@@ -107,10 +107,10 @@ function draw(
     }
     canvasCtx.stroke()
 
-    const timeData = synth.getWaveformLatest(Math.floor(synth.ctx.sampleRate * 0.025))
+    const timeData = synth.getWaveformLatest(Math.floor(synth.ctx.sampleRate * 0.05))
 
-    canvasCtx.lineWidth = 2
-    canvasCtx.strokeStyle = "#000"
+    canvasCtx.lineWidth = 1
+    canvasCtx.strokeStyle = "#0008"
     canvasCtx.beginPath()
     canvasCtx.moveTo(0, h / 2)
     for (let i = 0; i < timeData.length; i++)
diff --git a/src/RecordingPanel.tsx b/src/RecordingPanel.tsx
index 5aa9aae..348dc86 100644
--- a/src/RecordingPanel.tsx
+++ b/src/RecordingPanel.tsx
@@ -268,7 +268,7 @@ function draw(state: State)
     // Draw playing head
     if (state.playing)
     {
-        state.ctx.strokeStyle = "#00f"
+        state.ctx.strokeStyle = Common.colorSynth
         state.ctx.lineWidth = 2
         state.ctx.beginPath()
         state.ctx.moveTo(sampleIndexToX(state.playingIndex), 0)
diff --git a/src/VowelChart.tsx b/src/VowelChart.tsx
index 64a8ff1..b96e02c 100644
--- a/src/VowelChart.tsx
+++ b/src/VowelChart.tsx
@@ -20,6 +20,7 @@ export function VowelChart(props: {
         mousePosNormalized: { x: 0, y: 0 },
         mousePosFormants: { f1: 0, f2: 0 },
         mousePath: [],
+        formantPath: [],
     }
 
 
@@ -76,6 +77,7 @@ interface State
         f2: number
     }
     mousePath: PathPoint[]
+    formantPath: PathPoint[]
 }
 
 
@@ -272,15 +274,40 @@ function draw(
         state.ctx.fillText(vowel.symbol, x, y)
     }
 
+    // Draw extracted formants path
+    state.ctx.strokeStyle = Common.colorFormants
+    state.ctx.lineWidth = 2
+    for (let p = 1; p < state.formantPath.length; p++)
+    {
+        state.ctx.beginPath()
+        const timer = Math.max(0, state.formantPath[p].timer)
+        state.ctx.globalAlpha = timer
+
+        const pA = state.formantPath[p - 1]
+        const pB = state.formantPath[p]
+        const vecX = (pB.x - pA.x) * w
+        const vecY = (pB.y - pA.y) * h
+        const vecMagn = Math.sqrt(vecX * vecX + vecY * vecY)
+
+        if (vecMagn < w / 4)
+        {
+            state.ctx.moveTo(pA.x * w, pA.y * h)
+            state.ctx.lineTo(pB.x * w, pB.y * h)
+            state.ctx.arc(pA.x * w, pA.y * h, 2, 0, Math.PI * 2)
+        }
+
+        state.ctx.stroke()
+        state.ctx.globalAlpha = 1
+    }
+
     // Draw mouse path
-    state.ctx.strokeStyle = "#048"
+    state.ctx.strokeStyle = Common.colorSynth
     state.ctx.lineWidth = 2
     for (let p = 1; p < state.mousePath.length; p++)
     {
         state.ctx.beginPath()
         const timer = Math.max(0, state.mousePath[p].timer)
-        state.ctx.strokeStyle = Common.colorSynth
-        state.ctx.globalAlpha = 0.25 + 0.75 * timer
+        state.ctx.globalAlpha = timer
 
         const pA = state.mousePath[p - 1]
         const pB = state.mousePath[p]
@@ -306,6 +333,7 @@ function draw(
     if (state.mouseDown)
     {
         state.ctx.strokeStyle = Common.colorSynth
+        state.ctx.fillStyle = Common.colorSynth
         state.ctx.lineWidth = 2
         state.ctx.beginPath()
         state.ctx.arc(
@@ -328,6 +356,8 @@ function draw(
 
     
     const formants = synth.getCachedFormants()
+    state.formantPath.forEach((p) => p.timer -= 1 / 60)
+
     if (formants.length >= 2)
     {
         const f1 = formants[0]
@@ -336,6 +366,10 @@ function draw(
         const x = Math.floor(w - mapValueToView(f2, Common.f2Min, Common.f2Max) * w)
         const y = Math.floor(mapValueToView(f1, Common.f1Min, Common.f1Max) * h)
 
+        state.formantPath.push({ x: x / w, y: y / h, timer: 1 })
+        while (state.formantPath.length > 100)
+            state.formantPath.splice(0, 1)
+
         state.ctx.strokeStyle = Common.colorFormants
         state.ctx.fillStyle = Common.colorFormants
         state.ctx.lineWidth = 2
diff --git a/src/main.tsx b/src/main.tsx
index b6d4b92..1465877 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -24,8 +24,8 @@ function Page()
         }}>
             Click and drag around the top chart to synthesize vowel sounds via formant frequencies.<br/>
             <br/>
-            Red: computed frequency-domain data<br/>
-            Blue: computed formant frequencies<br/>
+            Red: extracted frequency-domain data from waveform<br/>
+            Blue: extracted formant frequencies from waveform<br/>
             <br/>
             <VowelChart synth={ synth() }/>
             <br/>
@@ -33,8 +33,8 @@ function Page()
             <br/>
             <RecordingPanel synth={ synth() }/>
             { " " }
-            <button onclick={ () => synth().openMic() }>
-                Allow Microphone
+            <button onclick={ () => synth().toggleMic() }>
+                Toggle Microphone
             </button>
         </div>
     </Solid.Show>
diff --git a/src/vowelSynth.ts b/src/vowelSynth.ts
index 8ec61d8..517a825 100644
--- a/src/vowelSynth.ts
+++ b/src/vowelSynth.ts
@@ -9,6 +9,10 @@ export class VowelSynth
     nodeFormant1Gain: GainNode
     nodeFormant2Filter: BiquadFilterNode
     nodeFormant2Gain: GainNode
+    nodeFormant3Filter: BiquadFilterNode
+    nodeFormant3Gain: GainNode
+    nodeFormant4Filter: BiquadFilterNode
+    nodeFormant4Gain: GainNode
     nodeAnalyser: AnalyserNode
     nodeAnalyserData: Uint8Array
     nodeAnalyserTimeDomainData: Float32Array
@@ -84,12 +88,38 @@ export class VowelSynth
         this.nodeFormant2Filter.Q.value = 5
         this.nodeFormant2Filter.connect(this.nodeFormant2Gain)
 
+        
+        this.nodeFormant3Gain = this.ctx.createGain()
+        this.nodeFormant3Gain.gain.value = 0
+        this.nodeFormant3Gain.connect(this.nodeAnalyser)
+        this.nodeFormant3Gain.connect(this.ctx.destination)
+
+        this.nodeFormant3Filter = this.ctx.createBiquadFilter()
+        this.nodeFormant3Filter.type = "bandpass"
+        this.nodeFormant3Filter.frequency.value = 0
+        this.nodeFormant3Filter.Q.value = 5
+        this.nodeFormant3Filter.connect(this.nodeFormant3Gain)
+
+        
+        this.nodeFormant4Gain = this.ctx.createGain()
+        this.nodeFormant4Gain.gain.value = 0
+        this.nodeFormant4Gain.connect(this.nodeAnalyser)
+        this.nodeFormant4Gain.connect(this.ctx.destination)
+
+        this.nodeFormant4Filter = this.ctx.createBiquadFilter()
+        this.nodeFormant4Filter.type = "bandpass"
+        this.nodeFormant4Filter.frequency.value = 0
+        this.nodeFormant4Filter.Q.value = 5
+        this.nodeFormant4Filter.connect(this.nodeFormant4Gain)
+
 
         this.nodeSource = this.ctx.createOscillator()
         this.nodeSource.type = "sawtooth"
         this.nodeSource.frequency.value = 90
         this.nodeSource.connect(this.nodeFormant1Filter)
         this.nodeSource.connect(this.nodeFormant2Filter)
+        //this.nodeSource.connect(this.nodeFormant3Filter)
+        //this.nodeSource.connect(this.nodeFormant4Filter)
         this.nodeSource.start()
 
 
@@ -111,13 +141,20 @@ export class VowelSynth
         const generalGain = 0.5
         this.nodeFormant1Gain.gain.value = gain * generalGain
         this.nodeFormant2Gain.gain.value = gain * generalGain * 0.8
+        this.nodeFormant3Gain.gain.value = gain * generalGain * 0.5
+        this.nodeFormant4Gain.gain.value = gain * generalGain * 0.2
     }
 
 
     setFrequencies(formant1Freq: number, formant2Freq: number)
     {
+        formant1Freq = Math.max(0, Math.min(5000, formant1Freq))
+        formant2Freq = Math.max(0, Math.min(5000, formant2Freq))
+
         this.nodeFormant1Filter.frequency.value = formant1Freq
         this.nodeFormant2Filter.frequency.value = formant2Freq
+        this.nodeFormant3Filter.frequency.value = 2700
+        this.nodeFormant4Filter.frequency.value = 3500
     }
 
 
@@ -205,10 +242,14 @@ export class VowelSynth
     }
 
 
-    async openMic()
+    async toggleMic()
     {
         if (this.nodeMicSrc)
+        {
+            this.nodeMicSrc.disconnect()
+            this.nodeMicSrc = undefined
             return
+        }
 
         try
         {