import sox
# create transformer
tfm = sox.Transformer()
# trim the audio between 5 and 10.5 seconds.
tfm.trim(5, 10.5)
# apply compression
tfm.compand()
# apply a fade in and fade out
tfm.fade(fade_in_len=1.0, fade_out_len=0.5)
# create an output file.
tfm.build_file('path/to/input_audio.wav', 'path/to/output/audio.aiff')
# or equivalently using the legacy API
tfm.build('path/to/input_audio.wav', 'path/to/output/audio.aiff')
# get the output in-memory as a numpy array
# by default the sample rate will be the same as the input file
array_out = tfm.build_array(input_filepath='path/to/input_audio.wav')
# see the applied effects
tfm.effects_log
> ['trim', 'compand', 'fade']

import numpy as np
import sox
# sample rate in Hz
sample_rate = 44100
# generate a 1-second sine tone at 440 Hz
y = np.sin(2 * np.pi * 440.0 * np.arange(sample_rate * 1.0) / sample_rate)
# create a transformer
tfm = sox.Transformer()
# shift the pitch up by 2 semitones
tfm.pitch(2)
# transform an in-memory array and return an array
y_out = tfm.build_array(input_array=y, sample_rate_in=sample_rate)
# instead, save output to a file
tfm.build_file(
    input_array=y, sample_rate_in=sample_rate,
    output_filepath='path/to/output.wav'
)
# create an output file with a different sample rate
tfm.set_output_format(rate=8000)
tfm.build_file(
    input_array=y, sample_rate_in=sample_rate,
    output_filepath='path/to/output_8k.wav'
)

import sox
# create combiner
cbn = sox.Combiner()
# pitch shift combined audio up 3 semitones
cbn.pitch(3.0)
# convert output to 8000 Hz stereo
cbn.convert(samplerate=8000, n_channels=2)
# create the output file
cbn.build(
    ['input1.wav', 'input2.wav', 'input3.wav'], 'output.wav', 'concatenate'
)
# the combiner does not currently support array input/output

import sox
# get the sample rate
sample_rate = sox.file_info.sample_rate('path/to/file.mp3')
# get the number of samples
n_samples = sox.file_info.num_samples('path/to/file.wav')
# determine if a file is silent
is_silent = sox.file_info.silent('path/to/file.aiff')
# file info doesn't currently support array input