Generate a Sound file with a 15Khz tone [closed]

Question

I'm playing around with high-pitched sounds. I'd like to generate an MP3 file with a 1 second 15Khz burst. Is there a simple way to do this from C or Python? I don't want to use MATLAB.

Answer 1

You could use Python's wave module to create a wave file which you could then compress to MP3. To create a one second 15khz sine wave:

import math
import wave
import struct

nchannels = 1
sampwidth = 2
framerate = 44100
nframes = 44100
comptype = "NONE"
compname = "not compressed"
amplitude = 4000
frequency = 15000

wav_file = wave.open('15khz_sine.wav', 'w')
wav_file.setparams((nchannels, sampwidth, framerate, nframes, comptype, compname))
for i in xrange(nframes):
    sample = math.sin(2*math.pi*frequency*(float(i)/framerate))*amplitude/2
    wav_file.writeframes(struct.pack('h', sample))
wav_file.close()

Answer 2

I would break this into 2 pieces:

1. Create a wave file using a C++ library(like libsndfile library)
2. Convert the wave file to mp3 using a utility (like lame). This is a command line tool which can be called from your C program as well. see -t for converting wave to mp3.

One thing to note is 15KHz is very high frequency to be heard by human and I guess most of speakers are not capable of playing it as it is beyond cutoff frequency of them. So don't be surprised if you don't hear the result.