Aerobika, or a similar device called Acapella, are PEP (Positive Expiratory Pressure) devices that cause a vibration in the lungs when used. The purpose is to help loosen the very sticky mucus many of us have in our lungs so it can be expelled more easily by "huff coughing" which is a way to bring up the mucus.
This is a fairly lengthy but very informative video about airway clearance: https://www.youtube.com/watch?v=1Ufj3oU_M2w

Think of airway clearance as semi-permanent maintenance for your lungs - it is doing what your body doesn't, with lungs damaged by bronchiectasis, COPD or Cystic Fibrosis - cleans out mucus, which is where the bad stuff grows. The Arikayce, on the other hand is the antibiotic to kill the MAC, and is only used until the infection is gone.

Here's a description of a regimen for a MAC/bronchiectasis patient: Please note your docs may alter the order for you.
1) Use airway-opening inhaler (if any - often something like albuterol, levalbuterol, Flovent or Breo)
2) Use a saline neb (many of us use 7%, thought to inhibit the growth of MAC)
3) Use the Aerobika or Acapella device as directed, with huff coughing, to clear out mucus (Some people use other clearance methods like a percussion vest, manual percussion, or postural drainage)
4) Use the prescribed inhaled medication as directed.
5) Thoroughly clean all nebulizer equipment and the airway device.
6) Take any other medication according to directed schedule.

This sounds really daunting, I know, but my morning regimen takes about 20 minutes, and I do it while reading email and the morning paper. When I had to do the inhaled Tobramycin as well, it took and additional 20 minutes. After 2 1/2 years, it's just a habit now.
Sue

PS My Mom had bronchiectasis (the underlying condition that predisposes to MAC & pseudomonas) - she lived to be 84 and died of a totally unrelated cause. Once diagnosed, she faithfully used her neb, and huff-coughed, but we didn't know about the Acapella back then.