うえぞうさんの uLipSyncWebGL (https://github.com/uezo/uLipSyncWebGL) の以下のファイルを以下のコードに上書き + WorkletProcessor.js は StreamingAssets に配置

uLipSyncWebGL.cs

using AOT;
using System;
using System.Runtime.InteropServices;
using UnityEngine;
using uLipSyncScript = uLipSync.uLipSync;

namespace ChatdollKit.Extension.uLipSync
{
    public class uLipSyncWebGL : MonoBehaviour
    {
        [DllImport("__Internal")]
        private static extern void InitWebGLuLipSync(Action callback, float[] samplingData);

        private static uLipSyncScript ulipSyncScript;

        private static float[] samplingData;

        private void Awake()
        {
#if UNITY_WEBGL && !UNITY_EDITOR
            samplingData = new float[128];
            ulipSyncScript = GetComponent<uLipSyncScript>();
            if (ulipSyncScript != null)
            {
                InitWebGLuLipSync(SetAudioSampleData, samplingData);
            }
#endif
        }

        [MonoPInvokeCallback(typeof(Action))]
        public static void SetAudioSampleData()
        {
            //Debug.Log($"=== SetAudioSampleData: {samplingData[0]}");
            if (!ulipSyncScript.audioSourceProxy)
            {
                ulipSyncScript.OnDataReceived(samplingData, 1);
            }
        }
    }
}

uLipSyncWebGL.jslib

mergeInto(LibraryManager.library, {
    $managed: {
        buffer: null,
        stream: null,
        source: null,
        worklet: null
    },

    InitWebGLuLipSync__deps: ['$managed'],
    InitWebGLuLipSync: function (notifyPtr, bufferPtr) {
        debugger;
        managed.buffer = new Float32Array(buffer, bufferPtr, 128);
        navigator.mediaDevices.getUserMedia({ audio: true }).then(stream => {
            managed.stream = stream;
            managed.source = WEBAudio.audioContext.createMediaStreamSource(stream);
            console.log(`=== sampleRate: ${WEBAudio.audioContext.sampleRate}`);
            return WEBAudio.audioContext.audioWorklet.addModule('/StreamingAssets/WorkletProcessor.js');
        }).then(_ => {
            managed.worklet = new AudioWorkletNode(WEBAudio.audioContext, 'ProcessAudioData');
            managed.source.connect(managed.worklet);
            managed.worklet.connect(WEBAudio.audioContext.destination);
            managed.worklet.port.onmessage = (e) => {
                managed.buffer.set(e.data);
                dynCall('v', notifyPtr);
            };
        });
    }
});

WorkletProcessor.js

class ProcessAudioData extends AudioWorkletProcessor {
    process([input], [output], parameters) {
        this.port.postMessage(input[0]);
        output[0].set(input[0]);
        return true;
    }
}
registerProcessor('ProcessAudioData', ProcessAudioData);