android "O" >= , Disable or Enable sound of the notification you use two ids for notification channel.
one for sounded notification and another is set when you want to disable
@RequiresApi(api = Build.VERSION_CODES.O)
private void createNotificationChannel(Context context, NotificationManager mNotificationManager, boolean playSound) {
// The user-visible name of the channel.
CharSequence name = context.getString(R.string.channel_name);
// The user-visible description of the channel.
String description = context.getString(R.string.channel_description);
int importance = NotificationManager.IMPORTANCE_HIGH;
NotificationChannel mChannel = new NotificationChannel(playSound ? channel_id_sound : channel_id_no_sound, name, importance);
// Configure the notification channel.
mChannel.setDescription(description);
mChannel.enableLights(true);
// Sets the notification light color for notifications posted to this
// channel, if the device supports this feature.
mChannel.setLightColor(Color.RED);
mChannel.enableVibration(true);
mChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
if (!playSound)
mChannel.setSound(null, null);
mNotificationManager.createNotificationChannel(mChannel);
}