在Ubuntu 12.04上的pyaudio输入设备无效

Question

这与此question类似，但我无法让PyAudio与EPD或系统安装一起使用。

In 1: import pyaudio
In [2]: pa = pyaudio.PyAudio()
In [3]: pa.get_default_input_device_info()
IOError                                   Traceback (most recent call last)
 in ()
----> 1 pa.get_default_input_device_info()


/usr/local/epd/lib/python2.7/site-packages/PyAudio-0.2.4-py2.7-linux-i686.egg/pyaudio.pyc in get_default_input_device_info(self)
    933         """
    934 
--> 935         device_index = pa.get_default_input_device()
    936         return self.get_device_info_by_index(device_index)
    937 

IOError: No Default Input Device Available

或者使用系统安装：

>>> import pyaudio
>>> pa = pyaudio.PyAudio()
>>> pa.get_default_input_device_info()
Traceback (most recent call last):
  File "", line 1, in 
  File "/usr/local/lib/python2.7/dist-packages/pyaudio.py", line 935, in get_default_input_device_info
    device_index = pa.get_default_input_device()
IOError: No Default Input Device Available

如何解决这个问题让PyAudio工作？