Баг со звуком Pygame

 import pygame  
import random  
 
pygame.init()  
 
screen = pygame.display.set_mode((1000,1000))  
pygame.display.set_caption("The Shiter Drive 1.0.1")  
icon = pygame.image.load("images/icon.png")  
pygame.display.set_icon(icon)  
 
car_x = 400  
car_y = 750  
car_speed = 10  
c2_speed = 2.5  
zvuk = 0  
 
fon = pygame.image.load("images/fonofon.png")  
car = pygame.image.load("images/car-up.png")  
zastavochka = pygame.image.load("images/no.png")  
 
pustinya = pygame.mixer.Sound("sounds/pustinya.mp3")  
pustinya.play(-1)  
mashinka = pygame.mixer.Sound("sounds/mashinka.mp3")  
 
quiter = True  
 
while quiter:  
 
    screen.blit(fon, (0,0))  
    screen.blit(car, (car_x, car_y))  
    screen.blit(zastavochka, (0,0))  
 
    keys = pygame.key.get_pressed()  
 
    if keys[pygame.K_LEFT] and car_x >= 0:  
        car = pygame.image.load("images/car-left.png")  
        car_x -= car_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
    if keys[pygame.K_RIGHT] and car_x <= 800:  
        car = pygame.image.load("images/car-right.png")  
        car_x += car_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
    if keys[pygame.K_UP]:  
        car = pygame.image.load("images/car-up.png")  
        car_y -= car_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
    if keys[pygame.K_DOWN] and car_y <= 800:  
        car = pygame.image.load("images/car-down.png")  
        car_y += car_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
    if keys[pygame.K_LEFT] and keys[pygame.K_UP] and car_x >= 0:  
        car = pygame.image.load("images/car-left-up.png")  
        car_x -= c2_speed  
        car_y -= c2_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
    if keys[pygame.K_RIGHT] and keys[pygame.K_UP] and car_x <= 800:  
        car = pygame.image.load("images/car-right-up.png")  
        car_x += c2_speed  
        car_y -= c2_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
    if keys[pygame.K_LEFT] and keys[pygame.K_DOWN] and car_x >= 0 and car_y <= 800:  
        car = pygame.image.load("images/car-left-down.png")  
        car_x -= c2_speed  
        car_y += c2_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
    if keys[pygame.K_RIGHT] and keys[pygame.K_DOWN] and car_x <= 800 and car_y <= 800:  
        car = pygame.image.load("images/car-right-down.png")  
        car_x += c2_speed  
        car_y += c2_speed  
        if zvuk == 0:  
            mashinka.play(-1)  
            zvuk = 1  
 
    # Проверка, если ни одна из клавиш не нажата, то остановить звук 
    if not any(keys): 
        if zvuk == 1: 
            mashinka.stop() 
            zvuk = 0 
 
    pygame.display.update()  
 
    for event in pygame.event.get():  
        if event.type == pygame.QUIT:  
            quiter = False  
            pygame.quit()