How to get numpy arrays output of .wav file format

In keeping with @Marco's comment, you can have a look at the Scipy library and, in particular, at scipy.io.

from scipy.io import wavfile

To read your file ('filename.wav'), simply do

output = wavfile.read('filename.wav')

This will output a tuple (which I named 'output'):

• output[0], the sampling rate
• output[1], the sample array you want to analyze

This is possible with a few lines with wave (built in) and numpy (obviously). You don't need to use librosa, scipy or soundfile. The latest gave me problems reading wav files and it's the whole reason I'm writting here now.

import numpy as np
import wave

# Start opening the file with wave
with wave.open('filename.wav') as f:
    # Read the whole file into a buffer. If you are dealing with a large file
    # then you should read it in blocks and process them separately.
    buffer = f.readframes(f.getnframes())
    # Convert the buffer to a numpy array by checking the size of the sample
    # width in bytes. The output will be a 1D array with interleaved channels.
    interleaved = np.frombuffer(buffer, dtype=f'int{f.getsampwidth()*8}')
    # Reshape it into a 2D array separating the channels in columns.
    data = np.reshape(interleaved, (-1, f.getnchannels()))

I like to pack it into a function that returns the sampling frequency and works with pathlib.Path objects. In this way it can be played using sounddevice

# play_wav.py
import sounddevice as sd
import numpy as np
import wave

from typing import Tuple
from pathlib import Path


# Utility function that reads the whole `wav` file content into a numpy array
def wave_read(filename: Path) -> Tuple[np.ndarray, int]:
    with wave.open(str(filename), 'rb') as f:
        buffer = f.readframes(f.getnframes())
        inter = np.frombuffer(buffer, dtype=f'int{f.getsampwidth()*8}')
        return np.reshape(inter, (-1, f.getnchannels())), f.getframerate()


if __name__ == '__main__':
    # Play all files in the current directory
    for wav_file in Path().glob('*.wav'):
        print(f"Playing {wav_file}")
        data, fs = wave_read(wav_file)
        sd.play(data, samplerate=fs, blocking=True)