最简单的边录音边播放 AudioRecord AudioTrac

        button.setOnClickListener(v -> {
            simpleRateInHz = 22050;
            bufferSize = AudioRecord.getMinBufferSize(simpleRateInHz, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
            audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, simpleRateInHz, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize);
            whetherRecord = true;
            audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, simpleRateInHz, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize, AudioTrack.MODE_STREAM);
            //开始录音
            a();
        });
    }

    private void a() { 
        new Thread(() -> {
            audioRecord.startRecording();
            while (true) {
                short[] audioBuffer = new short[bufferSize];
                int bufferReadResult = audioRecord.read(audioBuffer, 0, bufferSize);
                audioTrack.write(audioBuffer, 0, bufferReadResult);
                audioTrack.play();
            }
        }).start();
    }

最基础的实现方式, 资源释放, 及参数设置等, 参考其他大神的文章.