**3.2. Prerequisites for successful esophageal speech**

This method creates a new air reservoir used for speech within the esophagus of a lower capacity than the physiological one, which is the source of the sound wave. The capacity of the upper part of the esophagus after surgery is 60–80 ml of air [18], and the sound wave is generated by vibrations of the pharyngoesophageal segment in neoglottis, which allows the production of the esophageal voice. The exact localization of the pharyngoesophageal segment vibrations differs from author to author, and vibrations are possible from the base of the tongue to the upper esophageal sphincter, but most authors suggest that the most common vibrations of the pharyngoesophageal cavity vibration are at the level of the fifth, sixth and seventh cervical vertebrae, while Seeman feels that vibrations are at the level of the cricopharyngeal muscle at the height of the fifth cervical vertebra or where the pharyngoesophageal obstruction is the greatest [17].

In order for alaryngeal phonation to be possible (production of speech without the larynx), an appropriate tonus of pharyngoesophageal segment, more precisely the cricopharyngeal muscle, is needed. In determining the degree of tonus available, today there are two evaluation tools:


When using Taub's Insufflation Test, the examiner places the nasal catheter into the esophagus, using the Polyzer balloon to insufflate the air to the catheter. If the tonus is appropriate, the patient will be able to phonate, and the test will then record a positive result. The reference limit of the phonation pressure is 22 mmHg, which allows the 10 s alaryngeal phonation, or speech production in the range of 10–15 syllables in one inspiration. The phonation pressure is measured with a manometer. In cases where there is hypertonicity, the patient is not able to produce an alaryngeal voice, and the test registers a negative result [19].

The self-blowing test (modified Taube test) has been used for 33 years and was invented by Blom and Singer. The difference is that the other end of the nasal catheter is introduced into the tracheostoma and in this way allows an independent insufflation of the air from the tracheostoma to the esophagus. The result is recorded as positive when the patient can alaryngeally phonate for at least 8 s [20].

The negative result in these tests indicates undesirable hypertonicity of the muscle which prevents the phonation, and requires surgical intervention in the form of cricopharyngeal myotomy [20]. Muscle hypotonicity is also undesirable because it may interfere with alaryngeal phonation, but it often results in a very weak intensity of the alaryngeal voice. As the voice of low intensity does not meet the daily communication requirements, the hypotonicity can be compensated by external compression or surgical intervention.

In addition to the appropriate muscular tonus of the pharyngoesophageal segment, the person who will be rehabilitated with the esophageal speech must have a satisfactory level of certain cognitive abilities. Considered among the most important cognitive abilities are the appropriate intellectual status and the motivation of a person, but the conative factors are also significant. When choosing modality, psychosocial and socioeconomic factors are also important. The person who will learn the esophageal speech should be highly motivated for the process of rehabilitation, be patient enough, cognitively superior, and live in an empathetic and supportive family and social environment. Socioeconomic status should be as high as necessary for regular attendance at a speech-language therapy in continuity. Regarding the health status, people who will learn the esophageal speech should be of a good general health and somatic status, and the primary disease should be under good local control, which means removing any suspicion of local recurrence. Certainly, a significant influence on the possibility of this modality has the auditory status of the patient, and the level of hearing should be appropriate to the chronological age of the person, at the hearing level of 20–55 dB [5]. Any hearing impairment above 55 dB affects the communication function significantly and disables the adequate reception of the information from the speech-language therapist, thereby making it difficult and slowing down the process of rehabilitation.

Doyle classified contraindications for the learning of the esophageal speech in four categories [17, 21, 22]:

**1.** Certain physical factors

method an esophageal speech [17]. The method is the most natural way for the laryngectomized persons to have the alaryngeal phonation, which has made it the most commonly used method for many years. Although satisfying a number of factors is a prerequisite, Seeman considers the appropriate level of motivation to be the key factor for mastering the esophageal speech, and that most motivated patients successfully adopt this mode of substitution [17].

This method creates a new air reservoir used for speech within the esophagus of a lower capacity than the physiological one, which is the source of the sound wave. The capacity of the upper part of the esophagus after surgery is 60–80 ml of air [18], and the sound wave is generated by vibrations of the pharyngoesophageal segment in neoglottis, which allows the production of the esophageal voice. The exact localization of the pharyngoesophageal segment vibrations differs from author to author, and vibrations are possible from the base of the tongue to the upper esophageal sphincter, but most authors suggest that the most common vibrations of the pharyngoesophageal cavity vibration are at the level of the fifth, sixth and seventh cervical vertebrae, while Seeman feels that vibrations are at the level of the cricopharyngeal muscle at the height of the fifth cervical vertebra or where the pharyngoesophageal

In order for alaryngeal phonation to be possible (production of speech without the larynx), an appropriate tonus of pharyngoesophageal segment, more precisely the cricopharyngeal muscle, is needed. In determining the degree of tonus available, today there are two evalua-

When using Taub's Insufflation Test, the examiner places the nasal catheter into the esophagus, using the Polyzer balloon to insufflate the air to the catheter. If the tonus is appropriate, the patient will be able to phonate, and the test will then record a positive result. The reference limit of the phonation pressure is 22 mmHg, which allows the 10 s alaryngeal phonation, or speech production in the range of 10–15 syllables in one inspiration. The phonation pressure is measured with a manometer. In cases where there is hypertonicity, the patient is not able to

The self-blowing test (modified Taube test) has been used for 33 years and was invented by Blom and Singer. The difference is that the other end of the nasal catheter is introduced into the tracheostoma and in this way allows an independent insufflation of the air from the tracheostoma to the esophagus. The result is recorded as positive when the patient can alaryn-

The negative result in these tests indicates undesirable hypertonicity of the muscle which prevents the phonation, and requires surgical intervention in the form of cricopharyngeal myotomy [20]. Muscle hypotonicity is also undesirable because it may interfere with alaryngeal

produce an alaryngeal voice, and the test registers a negative result [19].

**3.2. Prerequisites for successful esophageal speech**

obstruction is the greatest [17].

70 Esophageal Cancer and Beyond

• Taub's insufflation test.

geally phonate for at least 8 s [20].

• Modified Taub's test.

tion tools:

	- the presence of psychological problems and psychopathology.
	- inability to attend a therapy at least three times a week.
	- immediately after laryngectomy, the necessity to speak loudly for a certain reason.

#### **3.3. Functional features of the esophageal speech**

The acoustic parameters of the esophageal voice in the literature vary depending on the researchers, the selected research method, the measuring instrument, the measuring criteria, the sample of subjects, and the environmental and computer program conditions in which the measurement was performed. The fundamental frequency, or the height of the esophageal voice, is reduced, the frequency range is reduced, and the acoustic parameters determining the timbre of the voice also differ significantly from the regular laryngeal voice [5, 23, 24]. Such values of acoustic parameters form a rough and breathy voice, subjectively experienced. In addition, the time for turning on the voice is prolonged and the maximum time of the phoning is significantly reduced. According to prosodic features, the melody of the esophageal voice is more uniform and variable, lexical stress is not realized or is partially realized, frequent undesirable respiratory pauses are often present and the tempo of speaking is slower [5].

on the correct technique of injecting speech air into the esophagus, and the other is based on the proper technique of eructation of speech air. **Figure 1** shows the scheme of esophageal

The Role of Esophagus in Voice Rehabilitation of Laryngectomees

http://dx.doi.org/10.5772/intechopen.78594

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There are several different methods of introducing speech air into the esophagus used in clinical speech therapy, namely: deglutition, inhalation, injection, blocking, Portman's, Tartapan's,

In 1900, Gottstein created and described the deglutition/swallowing method, and Gutzmann supplemented and propagated it. The method requires inserting the required air for the alaryngeal phonation according to the principle of swallowing or air ingestion as a bolus which causes eructation. This is considered the initial method because it allows a volitional ructus, but it affects the rhythm of speech and substantially slows it down, which is its disadvantage. As air swallowing, that is, "dry swallowing" is limited, it is recommended to consume the

In 1922, Seeman described the inhalation method, also referred to as aspirational or suctioning method. It requires a few swift inhalations that cause a sudden drop in intraoral pressure, which allows aspiration of air from the oral cavity into pharynx, and into the esophagus and relaxation of the pharyngoesophageal segment. When the pressures get equal, the air suction is stopped, the aspirated air is eructated and sounded through the pharyngoesophageal segment. Initially, the vocals are articulated, followed by the syllables made of a combination of gutural/h/ and vocals. Sometimes, the use of the method is followed by hyperventilation.

The injectable or occlusive method was formed by collecting the experiences of patients who noticed that the easiest way for them to loudly articulate occlusives and syllables combined from occlusives and vocals is alaryngeally. The method requires sufficient pressure of the tongue which causes air compression in the oral cavity and pharynx and is injected into the

There are several modifications of this method in the world.

voice production.

and their combinations [5, 17, 22].

fluid during therapy [17].

**Figure 1.** Esophageal voice production.

Sociofunctional features of the esophageal voice, which also make the advantage of this rehabilitation modality are: both hands free during speech and being less noticeable to the environment during speech, spontaneous and natural way of alaryngeal speech without additional surgery and insertion of foreign bodies, independence of prosthetic aids, the ability to speak without high consumption of material resources. On the other hand, the features that make up its shortcomings are: long periods of rehabilitation, lack of regular and continuous attendance at rehabilitation, discontinuous speech and additional undesirable noise during speech, especially tracheal noise during inspiration, which interfere with the intelligibility of the pronounced words [25].
