Talking after laryngectomy
After laryngectomy with removal of vocal cords, people can learn to talk again in most cases. This is done in three ways
1 Injection oesophageal speech
2 Prosthesis speech
Re 1 Injection oesophageal speech
Before the advent of the voice prosthesis, all laryngectomy patients learned talking again using the so-called injection method.
The method derives its name from the technique of compressing ('injecting') air from the oral cavity backwards in a specific way to produce explosive consonants / p /, / t / and / k /.
The air then returns by a kind of 'burping' causing the upper part of the oesophagus to vibrate. This generates sound.
Injection oesophageal speech may be learned in addition to prosthesis speech. In the event of e.g. voice prosthesis leakage, or if both hands are needed, speech is still possible. However, this method is much more difficult to learn than prosthesis oesophageal speech. Especially learning the compression and controlled return of air requires significant effort. Active movement of the tongue and lips play an important role.
Also breath control is a key aspect of injection oesophageal speech. People learn to generate injection speech independent of exhalation. Producing sound in prosthesis speech does depend on exhalation. This makes learning both techniques simultaneously difficult.
Talking by injection oesophageal speech is learned first under supervision of a specialised speech therapist.
Re 2 Prosthesis speech
To enable speech through a voice prosthesis, the stoma must be covered by a (bare) finger or thumb at the moment of exhalation. As the stoma is then closed, the exhaled air temporarily no longer flows through the tracheostoma. The exhaled air at the moment of stoma closure flows through the prosthesis to the oesophagus and throat cavity and then to the mouth.
The air vibrates the oesophageal mucus membrane and throat cavity, generating sound. Speech is enabled by moving the mouth in the normal way.
This is called prosthesis speech. The voice prosthesis itself therefore makes no sound. The voice prosthesis acts as a valve to channel exhaled air to the oral cavity.
During speech rehabilitation, the speech therapist will spend much time training the closure technique (e.g. which hand or finger is used). Also the moment of closure (during exhalation) is trained.
The stoma can be closed off by wearing a special plaster containing a filter that can be closed with the finger. The stoma can also be closed with a piece of gaze around the finger (without plaster of filter).
The speech therapist will train things like appropriate pressure, appropriate closure moment, correct placement of finger or thumb during closure, and the correct moment of release (not too soon and without additional sounds).
Re 3 Electrolarynx
If reasonable or good mastery of prosthesis speech or injection speech cannot be achieved, electronic speech equipment may be used, the so-called electrolarynx.
This is a tube-shaped device of about 14 cm that uses a rechargeable battery.
It has a vibration membrane at the top. During speech, this device is held against the floor of the mouth or the neck.
Tissue in the floor of the mouth transmits vibrations to air in the oral cavity, generating sound.
By making normal speech movements, this sound is converted to speech. The voice sounds mechanical and metallic, not like a normal voice.
A precondition for electrolarynx speech is that the tissue in the neck or floor of the mouth is flexible enough to transmit vibrations from the device to the oral cavity.
Correct placement of the device to the neck or floor of the mouth requires concentrated attention. Also good timing, coordination and practising clear and understandable speech is important.
Using an electrolarynx is learned under the supervision of a specialised speech therapist.