ALSA lib pulse.c:243:(pulse_connect) PulseAudio：无法连接：连接被拒绝

Question

我正在尝试在 Ubuntu-core 16.04 上测试 CMUSphinx 语音识别引擎。但我收到以下错误消息：

ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Connection refused

Error opening audio device default for capture: Connection refused
FATAL: "continuous.c", line 245: Failed to open audio device

我之前曾使用 Debian Jessie 成功测试过。但 Ubuntu 核心给了我这个错误！