The Raspberry Pi offers a nice embedded platform capable of providing near realtime voice recognition.
In order to respond to recognized text, a voice synthesis engine can be used. One can choose either a system running locally on the system such as festival or one that is executed remotely.
For a local solution, one such option is a program called festival.
sudo apt-get install festival
echo "Testing this out" | festival -tts
For the following steps you will also want to get your sound working. Make sure that you have a USB device attached that has a microphone in jack for this to work. Note, not all USB sound card devices may be compatible. sudo apt-get install ffmpeg sudo modprobe snd_bcm2835 sudo apt-get install alsa-tools alsa-oss flex zlib1g-dev libc-bin libc-dev-bin python-pexpect libasound2 libasound2-dev cvs
It maybe helpful to test out your ability to record and play back sounds before progressing to building out pocket-sphinx.
arecord -d 10 -D plughw:1,0 test.wav
aplay test.wav
Or even try streaming sound to another machine at
In order to get the speech recognition working, you will need an appropriate engine such as pocket-sphinx.
sudo apt-get install mplayer
sudo apt-get install libasound2-dev
sudo apt-get install bison
sudo apt-get install python-dev python2.7-dev python python-alsaaudio
wget http://downloads.sourceforge.net/project/cmusphinx/sphinxbase/0.8/sphinxbase-0.8.tar.gz
wget http://downloads.sourceforge.net/project/cmusphinx/pocketsphinx/0.8/pocketsphinx-0.8.tar.gz
Next change your directory into the sphinx base directory and type the following commands: ./configure –enable-fixed make sudo make install
Now change your directory into the pocket-sphinx directory and type the following commands: ./configure make sudo make install ./src/programs/pocketsphinx_continuous -samprate 48000 -nfft 2048 -adcdev hw:1,0
Custom dictionaries can be created for pocket-sphinx which greatly improve accuracy for command and control type applications. They can be specified with the -dict and -lm parameters: ./src/programs/pocketsphinx_continuous -samprate 8000 -nfft 2048 -adcdev hw:1,0 -lm 2530.lm -dict 2530.dic
Last modified: 04/04/2020