How to plot a wav file

Question

I have just read a wav file with scipy and now I want to make the plot of the file using matplotlib, on the \"y scale\" I want to see the aplitude and over the \"x scale\" I

Answer 1

Here is the code to draw a waveform and a frequency spectrum of a wavefile

import wave
import numpy as np
import matplotlib.pyplot as plt

signal_wave = wave.open('voice.wav', 'r')
sample_rate = 16000
sig = np.frombuffer(signal_wave.readframes(sample_rate), dtype=np.int16)

For the whole segment of the wave file

sig = sig[:]

For partial segment of the wave file

sig = sig[25000:32000]

Separating stereo channels

left, right = data[0::2], data[1::2]

Plot the waveform (plot_a) and the frequency spectrum (plot_b)

plt.figure(1)

plot_a = plt.subplot(211)
plot_a.plot(sig)
plot_a.set_xlabel('sample rate * time')
plot_a.set_ylabel('energy')

plot_b = plt.subplot(212)
plot_b.specgram(sig, NFFT=1024, Fs=sample_rate, noverlap=900)
plot_b.set_xlabel('Time')
plot_b.set_ylabel('Frequency')

plt.show()