To change dueration of audio file. we can also generate different voices with changing dueration and frame_rate.

change_duration.py

from pydub import AudioSegment as As
import os

def change(p_af, p_maf, duer, fr= None) :
    """$p_af is path of input audio file
    $p_maf is path for output audio file
    $duer = output audio file duration (in seconds)
    $fr = output audio file frame rate"""
    with open(p_af, 'rb') as af :
        sound = As.from_file(af)
    new_fr = int(sound.frame_count() / duer)
    m_sound = sound._spawn(sound.raw_data, #modified_sound
                           overrides={'frame_rate':new_fr})
    if fr != -1 : m_sound = m_sound.set_frame_rate(fr if fr else sound.frame_rate)
    m_sound.export(p_maf, format=os.path.splitext(p_maf)[1].replace('.',''))
    return len(m_sound), m_sound.frame_count(), m_sound.frame_rate