class Sampler

The Sampler class provides functionality to play sound samples. You generally create a Sampler object with the Sampler() factory function, as described in the section Creating a Sampler.

Example:

src = pool['bark.ogg']
my_sampler = Sampler(src, volume=.5)
my_sampler.play()

Things to know

Creating a Sampler

You generally create a Sampler with the Sampler() factory function, which takes the full path to a sound file as the first argument.

src = pool['bark.ogg']
my_sampler = Sampler(src)

Optionally, you can pass Playback keywords to Sampler() to set the default behavior:

src = pool['bark.ogg']
my_sampler = Sampler(src, volume=.5)

Sampling rate

If you find that your sample plays too slowly (low pitch) or too quickly (high pitch), make sure that the sampling rate of your sample matches the sampling rate of the sampler back-end as specified under backend settings.

Supported file formats

Sound files in .wav, .mp3, and .ogg format are supported. If you need to convert samples from a different format, you can use Audacity.

Playback keywords

Functions that accept **playback_args take the following keyword arguments:

• volume specifies a volume between 0.0 (silent) and 1.0 (maximum).
• pitch specifies a pitch (or playback speed), where values > 1 indicate a higher pitch, and values < 1 indicate a lower pitch.
• pan specifies a panning, where values < 0 indicate panning to the left, and values > 0 indicate panning to the right. Alternatively, you can set pan to 'left' or 'right' to play only a single channel.
• duration specifies the duration of the sound in milliseconds, or is set to 0 or None to play the full sound.
• fade_in specifies the fade-in time (or attack) of the sound, or is set to 0 or None to disable fade-in.
• block indicates whether the experiment should block (True) during playback or not (False).

src = pool['bark.ogg']
my_sampler = Sampler(src)
my_sampler.play(volume=.5, pan='left')

Playback keywords only affect the current operation (except when passed to Sampler() when creating the object). To change the behavior for all subsequent operations, set the playback properties directly:

src = pool['bark.ogg']
my_sampler = Sampler(src)
my_sampler.volume = .5
my_sampler.pan = 'left'
my_sampler.play()

Or pass the playback keywords to Sampler() when creating the object:

src = pool['bark.ogg']
my_sampler = Sampler(src, volume=.5, pan='left')
my_sampler.play()

close_sound(experiment)

Closes the mixer after the experiment is finished.

Parameters

• experiment: The experiment object.

init_sound(experiment)

Initializes the pygame mixer before the experiment begins.

Parameters

• experiment: The experiment object.

is_playing()

Checks if a sound is currently playing.

Returns

• True if a sound is playing, False if not.

Example

src = pool['my_sound.ogg']
my_sampler = Sampler(src)
my_sampler.play()
sleep(100)
if my_sampler.is_playing():
        print('The sampler is still playing!')

pause()

Pauses playback (if any).

Example

src = pool['my_sound.ogg']
my_sampler = Sampler(src)
my_sampler.play()
sleep(100)
my_sampler.pause()
sleep(100)
my_sampler.resume()

play(*arglist, **kwdict)

Plays the sound.

Parameters

• **playback_args: Optional playback keywords that will be used for this call to Sampler.play(). This does not affect subsequent operations.

Example

src = pool['my_sound.ogg']
my_sampler = Sampler(src)
my_sampler.play(pitch=.5, block=True)

resume()

Resumes playback (if any).

Example

src = pool['my_sound.ogg']
my_sampler = Sampler(src)
my_sampler.play()
sleep(100)
my_sampler.pause()
sleep(100)
my_sampler.resume()

set_config(**cfg)

Updates the configurables.

Parameters

• **cfg: The to-be-updated configurables.

stop()

Stops the currently playing sound (if any).

Example

src = pool['my_sound.ogg']
my_sampler = Sampler(src)
my_sampler.play()
sleep(100)
my_sampler.stop()

wait()

Blocks until the sound has finished playing or returns right away if no sound is playing.

Example

src = pool['my_sound.ogg']
my_sampler = Sampler(src)
my_sampler.play()
my_sampler.wait()
print('The sampler is finished!')