Cancer is a disease resulting from irregular development and spread of abnormal cells in one or more parts of the body. 1 Laryngeal cancer (▶ Fig. 9.1) is a subtype of head/neck cancer, which also includes oropharyngeal cancers, nasopharyngeal cancers, sinus cancers, and salivary gland cancers. Among all cancers, laryngeal cancer is considered rare with an estimated number of new cases for the United States in 2016 approximating 13,500. 1 Laryngeal cancer occurs more frequently in males, with the male-to-female ratio approximately 3.5:1. 1, 2
Fig. 9.1 Example of a T1 glottic cancer extending to the anterior commissure.
(From Fried M, Tan M. Clinical Laryngology. 1st ed. New York: Thieme Publishers, 2014.)
The most significant risk factor for the development of laryngeal cancer is tobacco use (e.g., smoking cigarettes and/or inhaling cigar smoke) and the risk increases dramatically when smoking occurs in conjunction with the regular and heavy use of alcohol. However, individuals who do not smoke or consume alcohol can also develop laryngeal cancer. There is a growing awareness that some laryngeal cancers are associated with human papillomavirus (HPV) infection, with reports suggesting that approximately 25% of laryngeal squamous cell carcinomas are associated with HPV, especially type 16. 3 The impact of laryngeal cancer and the subsequent medical treatment on the physiology of phonation can be substantial. A description of the clinical characteristics associated with laryngeal cancer was provided in ▒Chapter 2░. The focus of this chapter will be the specialized knowledge that is needed regarding the voice evaluation and treatment which occurs after oncology management.
9.3 Medical Management for Laryngeal Cancer
Once laryngeal cancer has been confirmed, the approach to medical management will depend on factors such as (1) the patient’s preferences, (2) the surgeon’s or oncologist’s recommendations, (3) knowledge and skills, (4) the site of cancer, and (5) the stage of cancer. Key considerations in the approach to treatment include the likelihood of eliminating the disease (cure) and the posttreatment quality of life for the patient. The approach to management for laryngeal cancer falls into three main categories: (1) surgery, (2) radiation therapy, and (3) chemotherapy. These treatments can be administered alone or in combination (e.g., surgery + radiation, or chemoradiation).
The stages of laryngeal cancer are identified in Box 9.1, and along with the site of the cancer within the larynx (subglottis, glottis, or supraglottis), the stage will greatly influence the choice of treatment. These stages relate to the TNM cancer staging system of the American Joint Committee on Cancer, 4 where
T = Tumor characteristics (e.g., size, growth into surrounding tissues).
N = Lymph node involvement.
M = Metastasis (spread of cancer cells to sites distant to the origin).
Box 9.1 Stages of laryngeal cancer (from the National Cancer Institute. Retrieved from www.cancer.gov on 8/10/16).
Stage 0 (Carcinoma in situ [CIS])
In stage 0, abnormal cells (dysplasia) are found in the lining of the larynx. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called “carcinoma in situ.”
In stage I, cancer has formed. Stage I laryngeal cancer depends on where cancer began in the larynx:
Supraglottis: Cancer is in one area of the supraglottis only and the vocal cords can move normally.
Glottis: Cancer is in one or both vocal cords and the vocal cords can move normally.
Subglottis: Cancer is in the subglottis only.
In stage II, cancer is in the larynx only. Stage II laryngeal cancer depends on where cancer began in the larynx:
Supraglottis: Cancer is in more than one area of the supraglottis or surrounding tissues.
Glottis: Cancer has spread to the supraglottis and/or the subglottis and/or the vocal cords cannot move normally.
Subglottis: Cancer has spread to one or both vocal cords, which may not move normally.
Stage III laryngeal cancer depends on whether cancer has spread from the supraglottis, glottis, or subglottis.
Stage III cancer of the supraglottis:
Cancer is in the larynx only and the vocal cords cannot move, and/or cancer is in tissues next to the larynx. Cancer may have spread to one lymph node on the same side of the neck as the original tumor and the lymph node is 3 cm or smaller; or
Cancer is in one area of the supraglottis and in one lymph node on the same side of the neck as the original tumor; the lymph node is 3 cm or smaller and the vocal cords can move normally; or
Cancer is in more than one area of the supraglottis or surrounding tissues and in one lymph node on the same side of the neck as the original tumor; the lymph node is 3 cm or smaller.
Stage III cancer of the glottis:
Cancer is in the larynx only and the vocal cords cannot move, and/or cancer is in tissues next to the larynx; cancer may have spread to one lymph node on the same side of the neck as the original tumor and the lymph node is 3 cm or smaller; or
Cancer is in one or both vocal cords and in one lymph node on the same side of the neck as the original tumor; the lymph node is 3 cm or smaller and the vocal cords can move normally; or
Cancer has spread to the supraglottis and/or the subglottis and/or the vocal cords cannot move normally. Cancer has also spread to one lymph node on the same side of the neck as the original tumor and the lymph node is 3 cm or smaller.
Stage III cancer of the subglottis:
Cancer is in the larynx and the vocal cords cannot move; cancer may have spread to one lymph node on the same side of the neck as the original tumor and the lymph node is 3 cm or smaller; or
Cancer is in the subglottis and in one lymph node on the same side of the neck as the original tumor; the lymph node is 3 cm or smaller; or
Cancer has spread to one or both vocal cords, which may not move normally. Cancer has also spread to one lymph node on the same side of the neck as the original tumor and the lymph node is 3 cm or smaller.
Stage IV is divided into stage IVA, stage IVB, and stage IVC. Each substage is the same for cancer in the supraglottis, glottis, or subglottis.
Cancer has spread through the thyroid cartilage and/or has spread to tissues beyond the larynx such as the neck, trachea, thyroid, or esophagus. Cancer may have spread to one lymph node on the same side of the neck as the original tumor and the lymph node is 3 cm or smaller; or
Cancer has spread to one lymph node on the same side of the neck as the original tumor and the lymph node is larger than 3 cm but not larger than 6 cm, or has spread to more than one lymph node anywhere in the neck with none larger than 6 cm. Cancer may have spread to tissues beyond the larynx, such as the neck, trachea, thyroid, or esophagus. The vocal cords may not move normally.
Cancer has spread to the space in front of the spinal column, surrounds the carotid artery, or has spread to parts of the chest. Cancer may have spread to one or more lymph nodes anywhere in the neck and the lymph nodes may be any size; or
Cancer has spread to a lymph node that is larger than 6 cm and may have spread as far as the space in front of the spinal column, around the carotid artery, or to parts of the chest. The vocal cords may not move normally.
Cancer has spread to other parts of the body, such as the lungs, liver, or bone.
Staging details for laryngeal cancer TNM domains are shown in ▶ Table 9.1. The greater the number associated with T (T0–T4), N (N0–N3), and M (M0 or M1) in combination will be associated with a more advanced stage of cancer. Smaller lesions at less advanced stages (e.g., state I or II) are often managed with a single modality treatment, while larger lesions at higher stages (e.g., stage II or IV) are managed with combined modalities.
Primary tumor (T)
Tumor cannot be assessed
No evidence of primary tumor
Carcinoma in situ
Tumor limited to one subsite of supraglottic with normal vocal fold mobility
Tumor invades more than one subsite of the supraglottic or glottis, without normal vocal fold mobility
Tumor limited to the larynx with vocal fold fixation and/or invades the postcricoid area, medial wall of the piriform sinus, or preepiglottic tissues
Tumor invades through the thyroid cartilage and/or extends to other tissues beyond the larynx
T1 (a and b)
Tumor limited to one vocal fold (T1a) or both vocal folds (T1b) with normal mobility—may involve anterior or posterior commissure
Tumor extends to the supraglottis and/or subglottis, and/or with impaired vocal fold mobility
Tumor limited to the larynx with vocal fold fixation
Tumor invades through the thyroid cartilage and/or extends to other tissues beyond the larynx
Tumor limited to the subglottis
Tumor extends to the vocal fold(s) with normal or impaired mobility
Tumor limited to the larynx with vocal fold fixation
Tumor invades through the cricoid or thyroid cartilage and/or extends to other tissues beyond the larynx
Regional lymph nodes
Regional lymph nodes cannot be accessed
No regional lymph node metastasis
Metastasis in a single ipsilateral lymph node, 3 cm or less in dimension
N2 (a, b, and c)
Metastasis in a single ipsilateral lymph node, less than 6 cm (N2a); or metastasis in multiple ipsilateral lymph nodes, less than 6 cm (N2b); or metastasis in bilateral or contralateral lymph nodes, less than 6 cm (N2c)
Metastasis in a lymph node more than 6 cm in dimension
Presence of distant metastasis cannot be assessed
No distant metastasis
While the approach to laryngeal cancer management will be specific to each individual case, current trends in North America reveal that early-stage cancers (CIS, stages I and II) are treated most commonly with radiation therapy or surgery alone, or in combination. 5, 6, 7 Some larger (e.g., T2–T4) or stage II cancers may include a combination of surgery plus radiation. Initial treatment with radiation or surgery results in similar survival rates, although there is recent evidence to suggest that initial surgery results in better long-term larynx perseveration (e.g., function) than initial radiation for the earliest stage cancers when they are located at the level of the glottis. 7, 8
Surgical approaches for laryngeal cancers are described in ▶ Table 9.2. Stage I or II lesions typically include endoscopic-guided transoral laser excision or open partial laryngectomies, which can include cordectomy for glottic cancer, supraglottic laryngectomy for supraglottic cancer, or a supracricoid laryngectomy for more advanced lesions. Early-stage cancer which does not respond to initial radiation or surgery may require a supracricoid laryngectomy or a total laryngectomy to eliminate the recurring lesions (in this context, they are referred to as “salvage” procedures).
Transoral laser surgery
Applied using CO2 laser with endoscopic visualization, and referred to as transoral laser microsurgery (TLM). Lesions are de-bulked and/or removed in pieces from the vocal fold tissue. Used most often for early-stage lesions, although some have used CO2 laser for larger and/or more advanced lesions. 9 TLM is utilized to perform a partial laryngectomy when removing margins of tissue surrounding the lesion, and is currently the most common surgical modality for removing cancerous tumors 10
Can be performed using cold steel instruments or CO2 laser. Partial laryngectomy procedures leave a portion of the laryngeal structure intact, with the aim of removing all cancer while persevering function
A portion of the vocal fold tissue or all of the vocal fold is removed. This surgery may include one or more vocal fold layers, from the cover through the vocal ligament and body, and may extend from the vocal process to the anterior commissure 11
Structures of the larynx superior to the vocal folds are removed. This may include the epiglottis, false vocal folds, thyroid cartilage, and aryepiglottic folds among other structures. Typically utilized for early-stage supraglottic lesions
Surgical excision of the true vocal folds, false vocal folds, ventricular spaces, and thyroid cartilage. For supraglottic lesions, it can include removal of the arytenoid cartilage and/or portions of the epiglottis. 12 Surgeons will reconstruct the larynx to preserve airway protection and voice by performing a cricohyoidpexy (hyoid bone attached to cricoid cartilage) or cricohyoidoepiglottopexy (hyoid and epiglottis are attached to cricoid). Used for larger (e.g., T2–T3) lesions and to avoid total laryngectomy
Removal of one true vocal fold, the corresponding vocal process of the arytenoid, and a portion of the ipsilateral thyroid cartilage and false vocal fold. The nature of this technique requires tracheostomy for a short duration postsurgery. Reconstruction can include tissue flaps to recreate the excised vocal fold
Surgical removal of the entire laryngeal framework. Because the upper respiratory tract is separated from the lower tract, a permanent tracheal stoma will be required
Research in the early 1990s demonstrated that survival rates are comparable when administering chemoradiation versus total laryngectomy for late-stage laryngeal cancers. 13 The standard treatment for later stage (III or IV) laryngeal cancer in North America is currently chemoradiation or radiation alone since these procedures “preserve” laryngeal structure. 14 Chemotherapy may be administered prior to radiation (referred to as “induction chemotherapy”) or concomitant with radiation. However, because survival rates for advanced subglottic laryngeal cancers are substantially lower than those for glottic and supraglottic lesions, later stage subglottic cancers will usually be treated initially with surgery plus radiation (with the surgical procedure administered first).
While the increased utilization of chemoradiation as the frontline treatment for late-stage cancer does preserve laryngeal structure, clinical experience and published reports suggest that acute and late radiation effects can substantially impair laryngeal function. 14, 15, 16 Effects of radiation can result in voice and/or swallowing impairments due to the following effects:
Inflammation and ulceration (mucositis).
Dry mouth (xerostomia).
Altered taste (dysgeusia).
Fibrosis in dermis, muscles, nerves.
Cranial nerve neuropathies.
When used in combination, chemotherapy will typically exacerbate the adverse effects of radiation. In addition, the systemic administration of cancer-fighting chemicals can cause anemia, bruising or bleeding, hair loss, fatigue, and an increased susceptibility to infection during the course of treatment.
The lymphatic system of the head and neck drains a large part of the laryngeal tissues, especially the supraglottic and subglottic regions (on the other hand, the glottis contains relatively sparse lymphatic drainage). The consequence of this is that supraglottic cancers and subglottic cancers are prone to metastasize into the deep lymph nodes located in the neck (cervical lymph nodes), which can then result in the spread of cancerous cells to distant organs (▶ Fig. 9.2). While early-stage glottic cancers rarely spread into the lymph system, more advanced glottic tumors have a greater chance of spread. 17 Lymph node metastasis can occur on the ipsilateral side of lesion origin or in the contralateral nodes. When biopsy confirms cancer cells in the cervical lymph nodes, it necessitates their treatment via radiation or surgical removal via a procedure known as a neck dissection. This may or may not be combined with postsurgical radiation treatment. This has implications for posttreatment voice rehabilitation, since the combination of substantial resections (which remove greater amounts of tissue) and radiation treatment can lead to fibrosis and possible limitations on certain alaryngeal speech options if a subsequent total laryngectomy is performed.
Fig. 9.2 The deep lymph nodes located in the neck serve as sites for regional metastasis of laryngeal cancer, and may necessitate treatment via radiation or surgical removal via neck dissection.
(From Baker E. Anatomy for Dental Medicine, 2nd ed. New York: Thieme Medical Publishers, 2016.)
When late-stage laryngeal cancers do not respond to chemoradiation or when lesions present an imminent threat and/or substantial impairment, total laryngectomy (TL) may be needed as a “salvage” operation or alternative choice. Although currently the number of annual TL procedures has drastically reduced, prior to the 1990s, TL was the primary treatment for late-stage and aggressive laryngeal cancer. 18 As illustrated in ▶ Fig. 9.3, TL involves removal of the entire laryngeal framework and tissues, sealing off the pharyngeal cavity from the trachea (the two no longer communicate with each other, although the upper esophageal sphincter (UES) remains intact so that the pharynx remains connected to the esophagus for swallowing), and the creation of a tracheal stoma through which air will be inspired and expired for respiration. Individuals who have received TL are often referred to as a “laryngectomee” (the affix “-ee” marks a person affected by an action, in this case, the act of performing a laryngectomy).
Fig. 9.3 Surgical site of total laryngectomy. The entire laryngeal framework is removed, disconnecting the upper and lower airways from each other. The communication between the pharynx and esophagus remains intact for swallowing.
Individuals undergoing laryngectomy might also be treated with an additional procedure at the time of surgery, called a tracheoesophageal puncture (TEP). A TEP creates a fistula (an opening) in the wall of tissue separating the trachea from the esophagus (the tracheoesophageal (TE) wall, as shown in ▶ Fig. 9.4. This puncture is created to facilitate placement of a speaking valve which will allow for respiratory airflow to be directed from the trachea into the esophagus for oral communication postsurgery.
Fig. 9.4 A permanent tracheal stoma (tracheostoma) is created at the base of the neck during the laryngectomy procedure which connects the lower respiratory tract (trachea, bronchi, and lungs) directly to the outside environment. A tracheoesophageal puncture (TEP—visible as the opening within the stoma) can also be created at the time of laryngectomy (primary TEP) or as a secondary procedure after laryngectomy (secondary TEP) to facilitate oral communication using a speaking valve.
9.4 Anatomical and Physiological Consequences of Laryngectomy
Removal of the larynx along with separation of the upper from lower respiratory tract will result in a number of permanent physiological changes to which an individual must adapt. Those scheduled to undergo a laryngectomy should be made aware of these changes prior to surgery so that they have time to consider and prepare for their presence. Suggestions for information provided to the patient by the speech–language pathologist (SLP) in the presurgical period are listed in ▶ Table 9.3. Unfortunately, presurgical consultation is not always feasible for many reasons, including (1) imminent requirement for surgery, (2) scheduling conflicts which arise between patient and/or various professionals, and/or (3) a lack of availability of interprofessional collaborative teams. A number of different health professionals might consult with the patient prior to surgery, including the otolaryngologist, radiologist, oncologist, and SLP. When the otolaryngologist plans to perform a primary TEP along with the laryngectomy procedure, it is important that both the physician and SLP counsel the patient in the preoperative period regarding the details of TE speech.
Anatomical and physiological changes
Surgery will remove the larynx—the sound source for voice will no longer be available
A permanent stoma will be created—inspiration and expiration of air occurs through that
If primary tracheoesophageal puncture will be performed, an opening will be created in the wall of tissue separating trachea and esophagus
Absence of air filtering, warming, and moistening by upper respiratory tract
Potential changes in the ability to smell, taste, sniff, sip
Coughing through stoma instead of mouth
Difficulty blowing the nose
May have difficulty being understood on telephone
Must be extra careful around water
Potential changes in ability to lift heavy objects
May need tracheostoma tube temporarily
Reinforce that they will speak again—in fact, they have multiple options
Immediately postsurgery, writing or messaging via digital devices will be available
Artificial electronic larynges—describe and show
Esophageal speech—describe and provide video examples if possible
Tracheoesophageal speech—describe and provide video examples if possible
Stoma and pulmonary care
Recommend covering stoma to minimize inhalation of particles which irritate trachea and lungs
Describe and demonstrate heat and moisture exchangers
Describe and demonstrate baseplates and adhesives
Describe strategies for protecting stoma around water
Describe maintenance of stoma and airway hygiene—regular inspection, removal of buildup, hydration of tissues
Explain components and demonstrate operative techniques of artificial electronic larynges
Describe and demonstrate (if possible—or show videos) esophageal speech
Describe and demonstrate (via products and videos) tracheoesophageal speech
Discuss patient’s preferences regarding communication
The information included in ▶ Table 9.3 relates to (1) the surgical alteration of laryngeal anatomy and function, (2) the postsurgical changes in breathing and phonation, (3) potential lifestyle changes, and (4) the choices for postlaryngectomy voice restoration. When consulting with the patient, the SLP must consider that many will experience psychological stress and anxiety due to their diagnosis and pending surgery. This can influence their ability to process information provided to them. The same is true for the immediate postsurgical period. The SLP should take time to provide rational explanations, rather than simple brute facts, regarding the changes the patient will experience. Additional explanations for the information shown in ▶ Table 9.3 can include the following:
The vocal folds have been removed so that the natural sound generator for speech is no longer available. However, individuals will be able to speak again, and multiple options will be available.
Because air no longer moves through the nose, oral cavity, pharynx, and larynx, there is an absence of filtering, warming, and moistening of air by cilia and mucosa of the upper respiratory tract. This can result in irritation to the mucosal lining of the trachea and lungs, with subsequent coughing and increased production and buildup of mucous secretions.
The lack of air movement through the nose can cause changes in the sensitivity to smell, taste, and changes in the ability to whistle, sniff, sip, and spit.
Individuals will still cough, although the burst of air resulting from cough will travel through the stoma, not the mouth (they must learn to cover the stoma, not the mouth, when coughing).
The disconnection between lower and upper respiratory tracts prevents direction of pulmonary air through the nose, making it difficult to clear the nostrils by “blowing” the nose. Individuals will still experience nasal secretions (e.g., runny nose), and may need to wipe their nose with a tissue more frequently.
Due to the presence of an open stoma leading directly to the trachea and lungs, individuals must be extra careful around water (e.g., bathing).
Some individuals may have trouble lifting very heavy objects due to the impairments caused by loss of the glottal effort closure reflex and an inability to fixate the thorax by impounding air below the vocal folds—air instead can leak out of the stoma.
Some patients may require a tracheostoma tube or vent (a.k.a., laryngectomy tube) to prevent stenosis (i.e., narrowing) of the stoma. These need to be cleaned frequently to avoid mucus buildup and/or blockage. Tracheostoma tubes or vents may be removed once the threat of stenosis has passed.
One of the most substantial physiological changes postlaryngectomy is the creation of a permanent tracheal stoma at the base of the neck (▶ Fig. 9.4), through which the individual will now inspire and expire air when breathing. Prior to surgery, the upper respiratory tract protected the trachea and lungs by preventing undesired substances from reaching the lower airway and also warming, humidifying, and filtering inspired air. The point at which inspired air reaches tracheal and lung tissue is much closer to the outside environment after laryngectomy, which necessitates conscious awareness and intentional precautions. These precautions can include covering the stoma with various materials (e.g., a water shield when taking a shower, a cloth when leaving the home), or wearing special filters over the stoma which will compensate for the lost upper respiratory tract functions. More detail is provided in section “Pulmonary Rehabilitation for the Laryngectomee.”
The vast majority of laryngectomees will be able to develop oral communication postsurgery, and most will have multiple communication options from which to choose. These options, along with pros and cons of each, are listed in ▶ Table 9.4. It is important to emphasize this fact during presurgical and immediate postsurgical consultations, as communication method will potentially be a major impact on quality of life for the laryngectomee. 19 In the immediate postsurgical period, while the patient is still healing, simple options are available including digital devices, writing, or simple communication boards. Patients who have undergone a primary TEP will be able to work on TE speech in the weeks after surgery. Two additional communication options include the use of an electronic artificial larynx and use of esophageal speech (ES).
Abbreviation: UES, upper esophageal sphincter.
9.5 Artificial Larynges
Humans communicate with one another using language and, for the vast majority of individuals, speech is the modality through which language is conveyed. It is obvious then that the loss of speech after laryngectomy can have consequences not only on the ability of one individual to communicate with another, but this disruption with communication may also affect routines for daily activities, and the overall psychological and emotional well-being of the patient. For many laryngectomees, use of an artificial larynx (AL) can provide relatively rapid postsurgical access to speech. ALs comprise one of the communication options which should be discussed during the presurgical consultation (▶ Table 9.3), and will require education and instruction during the postsurgical period to develop mastery of use for effective and efficient communication.
ALs are external communication aids which allow a laryngectomee to produce speech. ALs can be powered pneumatically (e.g., using the speaker’s own pulmonary energy) or using batteries, with battery-powered ALs sometimes referred to as an electronic AL (EAL) or “electrolarynx.” Pneumatic devices, as illustrated in ▶ Fig. 9.5, are typically designed with a coupler that covers the stoma, an internal vibratory source in the form of a thin rubber membrane powered by pulmonary air, and tubing which can be placed into the mouth to direct the acoustic energy for articulation. Pneumatic ALs have some unique advantages over electronic ALs including lower cost and the use of the speaker’s own air supply for power instead of batteries, which also reduces maintenance costs. However, there are hygiene issues that a patient must consider due to the need for cleaning the stoma coupler and tube that will be placed in the mouth to deliver sound energy. In addition, the position of the tube within the mouth may also influence the ability to articulate some sounds precisely.
Fig. 9.5 Example of a pneumatic artificial larynx (Tokyo Artificial Larynx, Limco Solutions, LLC; www.limcosolutions.com). The rubber membrane serving as the vibratory source is housed in the chamber immediately in front of the stoma coupler.
Treatment that incorporates a pneumatic AL can include goals centered on (1) operational procedure, (2) articulation, and (3) maintenance. 20 Speakers must learn how to adequately join the coupler to the stoma and time its placement with expiratory airflow and the initiation of speech. Exploration and practice with placement of the mouth tube is also needed to facilitate the most effective transmission of sound energy into the oral cavity with minimum interference on articulation. Low maintenance of pneumatic ALs is one of their advantages, although speakers will need to be educated regarding cleaning of mucous from the stoma coupler in addition to clearing saliva that may occlude the mouth tube. When user skills are adequate for effective and efficient operation, pneumatic AL voice quality can be perceptually preferred over other forms of alaryngeal speech, including EALs. 21, 22
The choice of a pneumatic AL over an EAL may be a function of cost, accessibility, ease of use, personal preference, and culture among other factors. Liao suggested that English-speaking communities utilize EALs more than pneumatic ALs, which aligns with the authors’ experiences that a majority of laryngectomees in the United States choose electronic devices. 23 EALs are battery-powered handheld devices which produce acoustic energy through a piston striking an internal membrane to sustain a vibratory tone. Recent models incorporate digital processing that allows for greater control of the frequencies and intensities produced by the device. As illustrated in ▶ Fig. 9.6, sound production from EALs is initiated by depressing a button located on the device frame, and then coupling the device head to the speaker’s neck to transmit acoustic energy into the oral cavity for articulation.
Fig. 9.6 An example of an electronic artificial larynx (InHealth Technologies). This particular product has two buttons to activate sound and a sliding knob to control loudness.
EALs have advantages over pneumatic devices and other forms of alaryngeal speech production, which include the following:
Can be a logical choice in advanced age due to ease of use.
Intraoral adaptors can be used when sound transmission through neck or cheek is difficult.
Hygiene issues are a minimal concern for neck/cheek placement.
Ease of use suggests EALs are a good choice for those with poor physical or mental health.
Maybe a good alternative if one fails at esophageal speech (ES).
Useful as a backup device for those who primarily depend on ES or TE speech.
If vibration is easily radiated into the oral cavity, intelligibility can be excellent.
There are disadvantages also, including the following:
Produces an unnatural, somewhat “robotic” sound.
Some elements of speech are difficult to produce using the EAL (/h/ sounds, cognates).
Calls attention to the speaker.
Requires the use of one hand.
Maintenance (batteries, replacement devices) can be expensive.
If it breaks, the patient is unable to communicate orally.
The treatment hierarchy for EALs is illustrated in ▶ Table 9.5, and moves from the development of simple operational skills to more advanced skills that will facilitate efficient use. In the acute postsurgical period, the tissue of the neck may be edematous and sensitive such that placement of an EAL on the neck may be too uncomfortable for the patient. Intraoral adaptors are also available when sound transmission through the neck is impaired. Some patients, due to significant postsurgical or postradiation scarring, may experience discomfort when pressing the EAL against the neck or may be unable to find a supple position on the neck where they can place the head of the EAL for sound transmission. These patients may require permanent use of an intraoral adaptor.
Education and orientation
When specific unit is chosen, describe components of device including pitch controls, volume controls, battery compartments, and/or charging instructions
Educate patient on routine care and maintenance of device
Demonstrate and assess ability to exhibit basic operational procedures, including orientation of device in a preferred hand, initiating sound with preferred finger(s), arm/hand movements with device in hand, and coupling of intraoral adaptor if needed
Locate the placement on neck which promotes most effective sound transmission to vocal tract—the goal is for sound to resonate in the oral cavity for speech articulation. Soft tissue will transmit sound well, while stiff tissue will reflect sound. Radiation treatment can cause stiff scar tissue on neck, so experiment with placement by seeking areas allowing for greater sound transmission into vocal trace
When neck transmission is poor, try different locations on tissue under the mandible, on the cheek, and/or the oral adapter
Instruct the patient on the application of the EAL head against the skin of the neck or cheek with the device on—practice varied coupling pressures with the goal of finding the most effective resonant sound quality. If the intraoral adaptor is needed, find the mouth placement which facilitates maximum transmission of sound with minimum interference with articulation
Instruct the patient to synchronize the tone onset (pressing tone button) with speech articulation. Initiating the tone early or late introduces a perceptually distracting buzz which can interfere with speech intelligibility. Appropriate timing also approaches more natural speech phrasing (e.g., we do not constantly produce phonation in-between phrases when speaking)
Build articulation skills by moving through a hierarchy of open sounds (those characterized by resonance and which are easier to produce with EAL—e.g., vowels, glides, nasals) to more closed sounds
/h/, fricatives, affricates, and distinctions between plosive cognates are typically the most difficult to produce
Help patient develop strategies to differentiate production of cognates (voiced/voiceless distinctions), which are the most difficult. Shortening articulation time of voiceless and lengthening voiced cognates is one strategy. Attempting to generate oral/pharyngeal pressures to create frication noise for voiceless cognates is another
If stoma noise is present when producing stop consonants, work on reducing muscle tension during articulation
Rate and phrasing
As articulation skills develop, work on developing a faster rate of speech with appropriate pausing to facilitate intelligibility
A natural speech rate with intelligible articulation should be the goal
Pitch and loudness adjustment
Instruct patient to modify intonation using strategies to adjust pitch and loudness. Most EALs have a loudness control knob which may be needed in noisy situations. Some devices have multiple buttons for differential pitch control
Loosening the EAL head (slightly unscrew it) can influence loudness (reduces overall amplitude of tone)
Pitch can also be varied by altering the amount of coupling pressure against the skin, moving the EAL head above or below the most resonant placement area (e.g., to a region with stiffer tissue), or extending/flexing the neck
Source: Adapted from Blom. 24
9.6 Esophageal Speech
Esophageal speech is a method of sound production requiring a speaker to “load” air into the esophagus from above and then expel that air back through the UES. The UES can serve as a pseudoglottis (replacement for the vocal folds) that oscillates to create sound energy. Many readers of this book might have produced sound with the UES when belching. In fact, the early learning stages of ES can take advantage of this familiarity. As ES skill develops, the perceptual features will often transition to a low pitched, rough vocal quality which can serve as the primary method of communication. Although ES can be difficult to acquire for many speakers, those who master it can communicate efficiently and effectively for most communicative needs. 25
The UES has also been referred to as the pharyngo-esophageal segment (PES), which distinguishes it as an anatomical region rather than an isolated muscular structure. 26 While PES and UES are often used synonymously, the PES is an anatomical region versus a specific sphincteric muscle in the case of the UES. The UES is composed of the distal fibers of the inferior pharyngeal constrictor (the cricopharyngeus muscle) and the circular muscle fibers that are part of the proximal esophagus (▶ Fig. 9.7). At rest, the UES is in a tonically active contracted state. This tight sphincter-like closure forms a high-pressure barrier between the esophagus and the pharynx which prevents air from passing into the esophagus during inhalation.
Fig. 9.7 Muscles of the pharynx (inferior pharyngeal constrictor) and esophagus forming the upper esophageal sphincter (UES), also known as the pharyngo-esophageal segment (PES).
(From Baker EW et al. Anatomy for Dental Medicine. 1st ed. New York: Thieme Publishers, 2015.)