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 Setting up USB microphone in Raspberry PI is not that easy. The most common errors are these. * Errr -9996, means that you have not specified input_device_index in PyAudio stream. * Segmentation fault, means you wrongly put input_device_index or did not start the application with sudo. * No audio stream input because I was using 2 in 1 microphone and earphone that I usually use to listen to music and answering call. This will not work, use a dedicated microphone instead. Here are a lot of links about how I was able to solve a problem of getting audio input into PyAudio application. * http://raspberrypi.stackexchange.com/questions/19705/usb-card-as-my-default-audio-device * http://raspberrypi.stackexchange.com/questions/28158/audio-and-microphone-configuration-of-usb-sound-card-on-r-pi * http://raspberrypi.stackexchange.com/questions/37177/best-way-to-setup-usb-mic-as-system-default-on-raspbian-jessie * http://raspberrypi.stackexchange.com/questions/39187/alsa-base-conf-file-missing * http://raspberrypi.stackexchange.com/questions/46799/usb-microphone-raspberry-pi * http://raspberrypi.stackexchange.com/questions/59852/pyaudio-does-not-detect-my-microphone-connected-via-usb-audio-adapter/ * http://raspberrypi.stackexchange.com/questions/9951/pyaudio-recording-sound-on-pi-getting-errors * http://raspberrypirecipes.blogspot.nl/2014/02/raspberry-pi-using-pyaudio-external.html * http://scruss.com/blog/2012/11/20/raspberry-pi-as-a-usb-audio-capture-device/ * http://stackoverflow.com/questions/38470321/ioerror-errno-invalid-output-device-no-default-output-device-9996 * http://www.linuxcircle.com/2013/05/08/raspberry-pi-microphone-setup-with-usb-sound-card/ * https://computers.tutsplus.com/articles/using-a-usb-audio-device-with-a-raspberry-pi--mac-55876 * https://learn.adafruit.com/usb-audio-cards-with-a-raspberry-pi/instructions * https://linuxconfig.org/how-to-test-microphone-with-audio-linux-sound-architecture-alsa From those links the most useful tutorial is, https://learn.adafruit.com/usb-audio-cards-with-a-raspberry-pi/instructions. And then I had a good discussion in Raspberry PI StackExchange that led me to solve the problem, http://raspberrypi.stackexchange.com/questions/59852/pyaudio-does-not-detect-my-microphone-connected-via-usb-audio-adapter/. Here is my compiled guide on how to get audio input from the USB audio adapter into PyAudio application. Use Raspbian Jessie, the latest version of Raspbian per January 2017. Do not use 2 in 1 microphone + earphone. This thing will not record anything into your Raspberry PI! Instead, use a dedicated microphone. sudo nano /usr/share/alsa/alsa.conf and then change these lines.

defaults.ctl.card 1
defaults.pcm.card 1

• ~/.asoundrc (without sudo) and /etc/asound.conf (with sudo) then change both into these (both will have same codes).

pcm.!default {
    type hw card 1
}
ctl.!default {
    type hw card 1
}

• Make sure both microphone and speaker are working.
• To test microphone do this, arecord --device=hw:1,0 --format S16_LE --rate 44100 -c1 test.wav. Then press CTRL + C to stop recording.
• To test what you have captures in microphone use this, aplay --device=plughw:1,0 test.wav.
• To test speaker do this, speaker-test -c2. There will be some white noises.
• At this point everything should be set.
• Run this script to know the index of the USB audio driver that is detected in PyAudio.

import pyaudio
p = pyaudio.PyAudio()
for i in range(p.get_device_count()):
    dev = p.get_device_info_by_index(i)
    print((i,dev['name'],dev['maxInputChannels']))

• Note the index on the of the USB audio driver you want to use.
• And then use in the arguments when you are initiating PyAudio object.
• Change the input_device_index into the index you found from the previous script.

    format = self.FORMAT,
    channels = self.CHANNELS,
    rate = self.SAMPLE_RATE,
    frames_per_buffer = self.PERIOD_SIZE_IN_FRAME,
    input_device_index = self.INPUT_DEVICE_INDEX,
    input = True)

• Start the PyAudio application with sudo. For example, sudo python -B my_pyaudio_application.py.
• If there is an Exception overflow error, change the streaming method from the microphone by using this, data = stream.read(chunk, exception_on_overflow = Fals.
• At this point I have no problem anymore. I can easily capture and stream sound from USB microphone into my PyAudio application.