How do I change the default soundcard in ubuntu 16.04 using pyaudio?

Question

I am trying to use pyaudio and pyspeech to record an audio sample and interpret what is said. I then intend to use that to trigger a conversation with an agent but I am having trouble with ALSA not using the on-board microphone.

Python program:

#!/usr/bin/env python3
# Requires PyAudio and PySpeech
import speech_recognition as sr

# Record Audio
r=sr.Recognizer()
with sr.Microphone() as source:
     print("Say something!") 
     audio = r.listen(source)

# Speech recognition using google speech recognition
try:
#this uses the generic API key which cannot query more than 50x per day
     print("You said: " + r.recognize_google(audio))
except sr.UnknownValueError:
     print("Google Speech Recognition could not understand audio")
except sr.RequestError as e:
     print("Could not request results from Google Speech Recognition service; {0}".format(e))

When I run it, I get the errors:

ALSA lib pcm_dsnoop.c:606:(snd_pcm_dsnoop_open) unable to open slave
ALSA lib pcm_dmix.c:1029:(snd_pcm_dmix_open) unable to open slave
ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm_dmix.c:1029:(snd_pcm_dmix_open) unable to open slave
Say something!

While is says "Say something!" it is not actually listening. I have tried the ALSA troubleshooting page: https://wiki.debian.org/ALSA#Troubleshooting

and get the following results:

$ cat /proc/asound/cards

produces:

 0 [HDMI           ]: HDA-Intel - HDA Intel HDMI
                      HDA Intel HDMI at 0xedc14000 irq 33
 1 [PCH            ]: HDA-Intel - HDA Intel PCH
                      HDA Intel PCH at 0xedc10000 irq 32

I can add myself as an audio user:

$sudo adduser jd audio
Adding user `jd' to group `audio' ...
Adding user jd to group audio
Done.

But when I go to edit the /etc/modprobe.d/sound it does not exist:

$ls /etc/modprobe.d/
alsa-base.conf              blacklist-rare-network.conf
blacklist-ath_pci.conf      blacklist-watchdog.conf
blacklist-bcm43.conf        dkms.conf
blacklist.conf              fbdev-blacklist.conf
blacklist-firewire.conf     intel-microcode-blacklist.conf
blacklist-framebuffer.conf  iwlwifi.conf
blacklist-modem.conf        libopenni-sensor-pointclouds0.conf
blacklist-oss.conf          mlx4.conf

What do I need to do to set the default microphone to the on-board microphone?

Answer 1

I have similar errors. This is how I fix is. For the first you need pulseaudio volume control program. Just run from terminal following command

sudo apt-get update && sudo apt-get install pavucontrol paman

Then run alsa audio_file_name.mp3

Then open pulseaudio from your gui. In Playback section you can find ALSA ,from the top right side you can chose default input/output device for ALSA and set your headphones for example