Why are my sounds lagging on my 13" Macbook Pro? System information: 2.4 GHz Intel Core i5, 8GB 1600 MHz DDR3 memory, running on Yosemite 10.10.3, 2014 Macbook pro retina model



Sound on my computer keeps lagging, but not sound on videos or anything like that. If I get an iMessage to my computer, I'll get the message right away but it will make the sound for it 5 minutes or so later. 

Same with emails. The sound is delayed to actually receiving them. I've tried restarting my computer and looking around the web, but I don't think it's my RAM, because I've only had the computer for less than a year.
I would RESET the Notification app:

Open the Library folder in your Home folder. Hold the &quot;alt&quot;key and use GO in Finder that will show you the Library folder

In the Library folder, open the Application Support folder.

Locate the folder named NotificationCenter. Drag this folder to the desktop.

Next, open the Terminal application.
Copy and paste each line of these commands into the Terminal window, in order. Press return after each line:
cd getconf DARWIN_USER_DIR
rm -rf com.apple.notificationcenter
killall usernoted; killall NotificationCenter

Close the Terminal app.

Restart your computer.


WARING: be very careful with the rm-rf part and make 101% sure you copied the correct text.