First, import the module:
import sounddevice as sd
Assuming you have a NumPy array named
myarray holding audio data with a
sampling frequency of
fs (in the most cases this will be 44100 or 48000
frames per second), you can play it back with
This function returns immediately but continues playing the audio signal in the
background. You can stop playback with
If you want to block the Python interpreter until playback is finished,
you can use
If you know that you will use the same sampling frequency for a while, you can
set it as default using
sd.default.samplerate = fs
After that, you can drop the samplerate argument:
If you don’t specify the correct sampling frequency, the sound might be played back too slow or too fast!
To record audio data from your sound device into a NumPy array,
you can use
duration = 10.5 # seconds myrecording = sd.rec(int(duration * fs), samplerate=fs, channels=2)
Again, for repeated use you can set defaults using
sd.default.samplerate = fs sd.default.channels = 2
After that, you can drop the additional arguments:
myrecording = sd.rec(int(duration * fs))
This function also returns immediately but continues recording in the background.
In the meantime, you can run other commands.
If you want to check if the recording is finished, you should use
If the recording was already finished, this returns immediately; if not, it waits and returns as soon as the recording is finished.
By default, the recorded array has the data type
default.dtype), but this can be changed with the dtype argument:
myrecording = sd.rec(int(duration * fs), dtype='float64')
Simultaneous Playback and Recording§
To play back an array and record at the same time, you can use
myrecording = sd.playrec(myarray, fs, channels=2)
The number of output channels is obtained from
but the number of input channels still has to be specified.
Again, default values can be used:
sd.default.samplerate = fs sd.default.channels = 2 myrecording = sd.playrec(myarray)
In this case the number of output channels is still taken from
(which may or may not have 2 channels),
but the number of input channels is taken from
In many cases, the default input/output device(s) will be the one(s) you want,
but it is of course possible to choose a different device.
query_devices() to get a list of supported devices.
The same list can be obtained from a terminal by typing the command
python3 -m sounddevice
Instead of the numerical device ID, you can also use a space-separated list of
case-insensitive substrings of the device name
(and the host API name, if needed).
default.device for details.
import sounddevice as sd sd.default.samplerate = 44100 sd.default.device = 'digital output' sd.play(myarray)
The aforementioned convenience functions
(as well as the related functions
get_stream()) are designed for small scripts and interactive use
(e.g. in a Jupyter notebook).
They are supposed to be simple and convenient,
but their use cases are quite limited.
If you need more control (e.g. continuous recording, realtime processing, …),
you should use the lower-level “stream” classes
either with the “non-blocking” callback interface or with the “blocking”
Stream.write() methods, see Blocking Read/Write Streams.
As an example for the “non-blocking” interface,
the following code creates a
Stream with a callback function
that obtains audio data from the input channels
and simply forwards everything to the output channels
(be careful with the output volume, because this might cause acoustic feedback
if your microphone is close to your loudspeakers):
import sounddevice as sd duration = 5.5 # seconds def callback(indata, outdata, frames, time, status): if status: print(status) outdata[:] = indata with sd.Stream(channels=2, callback=callback): sd.sleep(int(duration * 1000))
import sounddevice as sd duration = 5.5 # seconds def callback(indata, outdata, frames, time, status): if status: print(status) outdata[:] = indata with sd.RawStream(channels=2, dtype='int24', callback=callback): sd.sleep(int(duration * 1000))
We are using 24-bit samples here for no particular reason (just because we can).
See Example Programs for more examples.
Blocking Read/Write Streams§
Instead of using a callback function,
you can also use the “blocking” methods
(and of course the corresponding methods in