Why does the audio briefly slow down when pausing or unpausing a game?

[MaximRecoil]

Is this inherent to GroovyMAME and/or MAME on Linux (GroovyArcade)? I've never had it happen when running MAME in Windows.

I connected a PC to a JAMMA cabinet a few weeks ago, and at first I was using old hardware from 2006 (AMD Athlon 64 3700+) with GroovyArcade. I only loaded CPS-1, CPS-2, and CPS-3 games, and they all seemed to run at full speed, except for the brief audio slowdown when pausing/unpausing a game or when pressing Tab to bring up the settings OSD. Then I overclocked the CPU to 2.8 GHz, which makes it the equivalent of an FX-57. That didn't change anything. Then I tried newer hardware: Intel Core i5-650, which is far more powerful than an FX-57:

http://cpuboss.com/cpus/Intel-Core-i5-650-vs-AMD-Athlon-64-FX-57

That didn't change anything either.

Today I tried an Intel Pentium G3258, which is far more powerful than an i5-650, and is the same CPU that I use in my main PC:

http://cpuboss.com/cpus/Intel-Pentium-G3258-vs-Intel-Core-i5-650

And again, that didn't change anything. Since I have the same CPU in my main PC, I know it will run the current version of MAME and any CPS game in Windows without any slowdown of the audio whatsoever when pausing/unpausing. Currently, the one in my main PC is overclocked to 4.5 GHz, which gives it single-thread performance that's on par with or better than most any current CPU on the market, regardless of price, but I ran it for a long time at stock speed (3.2 GHz), so I know how it runs CPS games in Windows MAME at stock speed.

I could probably overclock the G3258 in my MAME PC to 4.5 GHz too, but I don't want to do it with the stock heatsink that's in there, and I suspect it wouldn't make any difference anyway, considering a jump from a 3700+ from 2006 to a G3258 from 2014 didn't make a difference (well, it made everything snappier overall, and made it boot a lot faster, but that audio slowdown when pausing/unpausing and pressing the Tab key is still there).

The CPS games aren't even very CPU intensive to emulate, especially CPS-1, which is from 1988. Even the first PC I ever bought, in 2001, which had a lowly 733 MHz Celeron, ran CPS-1 and CPS-2 games fine in the then-current version of Windows MAME (CPS-3 wasn't emulated yet at the time). That PC's limit was Mortal Kombat 3, which it ran with noticeable video and audio slowdown. That was solved with an Athlon XP 1800+ in 2002 that ran everything at full speed except for the games that no one could run at full speed at the time, like Cruis'n USA. The 3700+ in 2006, overclocked to 2.8 GHz, ran Cruis'n USA at pretty much full speed though, in Mame32 v.105 in Windows XP.

[Calamity]

This is due to the soundsync feature, not present in baseline MAME. Since the speed suddendly drops to zero, and then suddendly goes back to 100%, you notice a glitch as sound catches up.

[MaximRecoil]

What's the benefit of the soundsync feature, and can it be disabled? Last night I noticed the brief audio slowdown in SFIII: Third Strike during the actual game, not just when pausing or pressing the Tab key. It happened at some point during the continue game process, when you're selecting a character, etc.; it happened at the point that you pressed a button to make one of the selections, and it happened at that same point every time.