Being a member of a head and neck support group means that I have become acutely aware of the challenges faced by people who have had a laryngectomy. I have always found it hard to understand how the speech valves work so have now made an effort to get to grips with it. Here goes:
This diagram shows how the trachea is separated from the oesophagus and has its outlet through a stoma in the neck. 
Larys breathe through a hole in throat because the trachea or windpipe has had the larynx removed and outlet diverted to a stoma or hole in the neck. This means air goes straight into lungs without the filter of a mouth and nose. Not good. We pushed for the Heat Moisture Exchange filters provided by Atos for years and now most DHBs provide them free. Before HMEs, people wore a stoma cover, a piece of sponge or nothing at all. Some people still prefer this. Sometimes, having anything on the radiated skin can be painful. What people refer to as the speech prosthesis or valve is a small tube (?) that goes from the trachea to the oesophagus to enable people to push air up through the oesophagus to the throat and mouth so they can speak. (The throat can vibrate.) There’s a valve at the end (like an open/shut trapdoor) to stop food leaking into the trachea and hence the lungs. When this valve fails to close, leaking occurs. It’s often due to yeast/thrush getting into the valve or acid reflux from the stomach causing it to deteriorate. Sometimes there is no known reason. The hole that connects the trachea and the oesophagus is called a puncture or fistula. When there’s leakage it’s VERY uncomfortable for the patient. They can get aspiration pneumonia if they’re not careful but at the very least they cough a lot and can’t eat or drink until the valve is changed. This causes distress to an already hard-pressed patient. The valve can be plugged but the patient has to have the right plug and know how to use it. Not all hospitals have an expert on hand who can change the valve right away. It can be done by nurses and SLTs or an ENT specialist. As we all know, these mishaps tend to occur at night or in the weekends … Some patients get the right valve for them and can go ages without a leak. For patients with frequent leaks there is an expensive valve made from a material that repels yeast and has magnets to make sure the valve stays functional. It’s called an Activalve by the Atos company. (The Blomsinger company supplies something similar.) Like most laryngectomy products, it hits the DHB in the pocket but should be cost effective if frequent valve changes can to be prevented. Some people get so stressed by the frequent valve changes that they want the valve removed and for the puncture to heal and close. They can’t talk but prefer it to leaking-valve-stress. There are other ways of talking apart from this trans oesophageal puncture, or TEP, but they tend to be harder and for patients who have had a glossectomy too, they don’t work. Sometimes it’s not the valve leaking that causes the aspiration of food and liquid into the lung, the prosthesis might be loose because radiation damage and leaking can occur around it. Sometimes the fissure or puncture has to be sewn up, the tissue needs to heal, then a new puncture made. Some patients have gone without a valve for weeks or months but even with limited speech they deeply regret the loss of voice. For those who have developed near normal speech it is a terrible blow to lose the prosthesis. We are thankful for the nurses, SLTs and specialists who help our laryngectomees. They are a small and special group of patients and we’ve always wanted them to have gold standard devices to maintain their quality of life.