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Summary Objectives The purpose of the present study was to establish the method for an acoustic simulation of a vocal tract created from CT data during phonation of the Japanese vowel /a/ and to verify the validity of the simulation. Material and methods The subjects were 15 healthy adults (8 males, 7 females). The vocal tract model was created from CT data acquired during sustained phonation of the Japanese vowel /a/. After conversion to a mesh model for analysis, a wave acoustic analysis was performed with a boundary element method. The wall and the bottom of the vocal tract model were regarded as a rigid wall and a nonrigid wall, respectively. The acoustic medium was set to 37°C, and a point sound source was set in the place corresponding to the vocal cord as a sound source. The first and second formant frequencies (F1 and F2) were calculated. For 1 of the 15 subjects, the range from the upper end of the frontal sinus to the tracheal bifurcation was scanned, and 2 models were created: model 1 included the range from the frontal sinus to the tracheal bifurcation; and model 2 included the range from the frontal sinus to the glottis and added a virtually extended trachea by 12 cm cylindrically. F1 and F2 calculated from models 1 and 2 were compared. To evaluate the validity of the present simulation, F1 and F2 calculated from the simulation were compared with those of the actual voice and the sound generated using a solid model and a whistle-type artificial larynx. To judge the validity, the vowel formant frequency discrimination threshold reported in the past was used as a criterion. Namely, the relative discrimination thresholds (%), dividing ▵F by F, where F was the formant frequency calculated from the simulation, and ▵F was the difference between F and the formant frequency of the actual voice and the sound generated using the solid model and artificial larynx, were obtained. Results F1 and F2 calculated from models 1 and 2 were similar. Therefore, to reduce the exposure dose, the remaining 14 subjects were scanned from the upper end of the frontal sinus to the glottis, and model 2 with the trachea extended by 12 cm virtually was used for the simulation. The averages of the relative discrimination thresholds against F1 and F2 calculated from the actual voice were 5.9% and 4.6%, respectively. The averages of the relative discrimination thresholds against F1 and F2 calculated from the sound generated by using the solid model and the artificial larynx were 4.1% and 3.7%, respectively. Conclusions The Japanese vowel /a/ could be simulated with high validity for the vocal tract models created from the CT data during phonation of /a/ using the boundary element method.

Summary Aim Previous reports have demonstrated good outcomes with the use of the Anterolateral Thigh Flap (ALT) in pharyngeal reconstruction. We report a new modification of free ALT flap pharyngeal reconstruction utilizing vascularised fascial wings or extensions placed in the parastomal gutters to cover the major neck vessels. Patients and methods This was a single-centre retrospective case review. Between November 2017 and January 2019, 8 patients (6 male, 2 female mean age 61, range 35 to 74) underwent near circumferential pharyngeal reconstruction by the modified technique. 3 patients had laryngopharyngectomy for radiorecurrent larynx SCC, 2 for primary, advanced laryngeal SCC, and 3 for primary hypopharyngeal SCC. Results All eight patients regained adequate swallow to maintain nutrition without tube-feeding. Two of the patients have been assessed as appropriate for tracheo-esophageal puncture and are awaiting placement. One patient uses an electrolarynx for speech and 5 patients aphonic only. One patient died 2 months after the procedure from chest infection. There were no flap failures, no fistulas and no strictures at one year. One patient who underwent a salvage laryngopharyngectomy experienced parastomal wound dehiscence, but critically there was no return to theatre for exposed major vessels and the wound healed within 6 weeks requiring dressings only. Conclusion Here we report outcomes of pharyngeal reconstruction with a modified single perforator free ALT flap using fascial extensions to line the parastomal gutters. In the event of parastomal dehiscence, the placement of vascularized tissue parastomally may facilitate spontaneous healing and prevent major vessel exposure.

The electrolarynx (EL) is an electromechanical device that enables patients to produce voice following the surgical removal of their larynx. The purpose of this study is to understand the acoustic and perceptual characteristics of Mandarin consonants produced by EL speakers. First, the acoustic characteristics (including speech intensity, consonant duration, spectral peak, and F2 onset) of Mandarin EL consonants are investigated by comparing the EL and normal consonants. Then, a perceptual evaluation of EL consonants is conducted to identify the relationship between acoustical characteristics and perceptual intelligibility. The results suggest three consonant confusion types are mainly responsible for the poor intelligibility of Mandarin EL consonants: (1) the “unaspirated-for-aspirated” confusion caused by the significantly shortened voice onset time of aspirated consonants; (2) the “voiced-for-voiceless” confusion caused by the continuous pulsing of the EL device and low consonant intensity; and (3) the “perceptual omission” caused by low intensity of consonants and / or consonant omission. The results obtained are promising and potential for further improvements in Mandarin EL speech intelligibility.

PurposeTo assess feasibility of producing intelligible and comprehensible speech with an electrolarynx; measure anxiety, communication ease, and satisfaction before/after electrolarynx training; and identify barriers/facilitators.MethodsWe included tracheostomized adults from 3 units following commands, reading English, and mouthing words. On enrolment, we measured anxiety, ease, and satisfaction with communication. We gave electrolarynx instruction for ≤5 days then 2 independent raters assessed intelligibility, sentence comprehensibility (9-point difficulty scale), and Electrolarynx Effectiveness Score (EES), and re-evaluated anxiety, communication ease, and satisfaction. Interviews explored barriers/facilitators.Measurements and main resultsWe recruited 24 participants (Jan2015-Dec2016). Mean (SD) intelligibility was 45%(18%) words correct: 57%(21%) when facing. Mean comprehension difficulty was 6.4(2.0) overall, indicating moderate difficulty (5.5(2.5) scored visualizing). Mean EES was 2.9(1.0) (3 = improved lip-reading through recognizable sounds). Anxiety decreased from median 3.8 to 2.0 (P = .007). Communication was rated easier (median 15 vs 12, P = .04) whereas satisfaction remained similar (P = .06). Facilitators included device friendliness, patient independence, and word intelligibility. Barriers were patient weakness, difficulty positioning the device, and limited sentence as opposed to word intelligibility.ConclusionThe electrolarynx may aid intelligible speech for some tracheostomized patients if the communication partner can visualize the users face, and reduce anxiety and make patient perceived communication easier.

Purpose To determine the influence of clear speech on auditory-perceptual judgments of speech acceptability and listener comfort for electrolaryngeal speech. Method Voice recordings were obtained from 10 electrolaryngeal speakers. Each speaker read the Rainbow Passage in two conditions: habitual speech and clear speech. Speakers were encouraged to speak as clearly as possible and over-articulate in the clear speech condition. Auditory-perceptual rating tasks were completed by 20 normal-hearing adults who evaluated 20 randomized voice recordings. Two counterbalanced listening sessions were used to gather ratings of speech acceptability and listener comfort. Results A significant effect of speaking condition was found on listener judgments of speech acceptability, but not listener comfort. However, listener scores for speech acceptability and listener comfort were found to be significantly related. For all speakers, objective temporal measures indicated reduced speaking rates in the clear speech condition. Conclusions These findings suggest that volitional attempts to improve electrolaryngeal speech using clear speech might negatively impact listener judgments of speech acceptability, but not listener comfort. Further, the data suggest that speech acceptability and listener comfort might address unique perceptual entities. Overall, the strong relationship between these auditory-perceptual dimensions provide support for the use of scaled measurements to assess the impact of speech rehabilitation on individuals who use the electrolarynx.

Purpose Perceived listening effort is a perceptual dimension used to identify the amount of work necessary to understand disordered speech. The purpose of this study was to investigate the utility of perceived listening effort to provide unique information about disordered speech. The relationships between perceived listening effort and two current outcome measures (speech acceptability, intelligibility) were examined for listeners rating electrolaryngeal speech, along with their reliability and intra-rater agreement. Methods Ten healthy male speakers read low-context sentences using an electrolarynx. Twenty-five inexperienced listeners orthographically transcribed and rated the stimuli for perceived listening effort and speech acceptability using a visual analog scale. Strict reliability and agreement criteria were set. Results Perceived listening effort was moderately to strongly correlated with intelligibility (r = −0.76) and acceptability (r = −0.80), each of which contributed uniquely to ratings of perceived listening effort. However, only 17 listeners met stringent reliability and agreement criteria. Conclusions Ratings of perceived listening effort may provide unique information about the communicative success of individuals with communication disorders. There is great variability, however, among inexperienced listeners’ perceptual ratings of electrolaryngeal speech. Future research should investigate variables that may affect perceived listening effort specifically and auditory-perceptual ratings in general.

Electrolaryngeal speech, for persons who have lost their larynx, suffers from the drawback of susceptibility to acoustic noise, which includes inherent electrolarynx motor noise as well as environmental noise. Interactions with electrolarynx users motivated the authors to investigate a crucial drawback of electrolaryngeal speech: degradation of electrolaryngeal speech under noisy environments. The effect of contemporary methods of speech enhancement, viz. noise power spectral density estimation based d-dimensional amplitude trimmed estimation (DATE), and non-negative matrix factorization (NMF) based algorithms, were studied and evaluated for electrolaryngeal speech degraded by noise. Electrolaryngeal speech was corrupted using three types of noisy scenarios at low signal to noise ratios (0, −5 and −10 dB SNR). Objective testing based on the perceptual evaluation of speech quality (PESQ) standard, as well as subjective testing by 14 participants based on the ITU-T P.835 standard were performed. Word-centric intelligibility testing was also performed. The results indicated an improvement in the speech quality. The subjective testing results were further analyzed using one-way analysis of variance (ANOVA) and multiple paired comparison using Tukey’s honest significant difference (HSD) criterion. The overall speech quality of NMF algorithms was found to be significantly higher than that of DATE-based algorithms for the test conditions. The results show that speech enhancement algorithms can aid in improving the electrolaryngeal user experience by reducing the effect of acoustic noise.

We created an electrolarynx (EL) that generates tonal distinctions in Mandarin.Tones are identified with greater accuracy in the tonal vs. monotone EL condition.Tonal information enhances EL speech intelligibility and acceptability. An electrolarynx (EL) is a valuable rehabilitative option for individuals who have undergone laryngectomy, but current monotone ELs do not support controlled variations in fundamental frequency for producing tonal languages. The present study examined the production and perception of Mandarin Chinese using a customized hand-held EL driven by computer software to generate tonal distinctions (tonal EL). Four native Mandarin speakers were trained to articulate their speech coincidentally with preprogrammed tonal patterns in order to produce mono- and di-syllabic words with a monotone EL and tonal EL. Three native Mandarin speakers later transcribed and rated the speech samples for intelligibility and acceptability. Results indicated that words produced using the tonal EL were significantly more intelligible and acceptable than those produced using the monotone EL.

The majority of laryngectomees use the electrolarynx as their primary mode of verbal communication after total laryngectomy surgery. However, the archetypal electrolarynx suffers from a monotonous tone and the inconvenience of requiring manual control. This paper presents the potential of pattern recognition to support electrolarynx use by predicting fundamental frequency (F0) and voicing state (VS) from surface EMG of the infrahyoid and suprahyoid muscles, as well as from a respiratory trace. In this study, surface EMG signals from the infrahyoid and suprahyoid muscle groups and respiratory trace were collected from 10 able-bodied, adult males (18–60 years old). Participants performed three kinds of vocal tasks – tones, legatos and phrases. Signal features were extracted from the EMG and respiratory trace, and a Support Vector Machine (SVM) classifier with radial basis function kernels was employed to predict F0 and voicing state. An average root mean squared error of 2.81 ± 0.6 semitones was achieved for the estimation of vocal frequency in the range of 90–360 Hz. An average cross-validation (CV) accuracy of 78.05 ± 6.3% was achieved for the prediction of voicing state from EMG and 65.24 ± 7.8% from the respiratory trace. The proposed method has the advantage of being non-invasive compared with studies that relied on intramuscular electrodes (invasive), while still maintaining an accuracy above chance. Pattern classification of neck-muscle surface EMG has merit in the prediction of fundamental frequency and voicing state during vocalization, encouraging further study of automatic pitch modulation for electrolarynges and silent speech interfaces.

The electrolarynx (EL) is a widely used device for alaryngeal communication, but the low quality seriously reduces the intelligibility of EL speech. To improve EL speech quality, a vowel-specific voice source based on visual information of lip shape and movements and artificial neural network (ANN) is implemented into an experimental EL (SGVS-EL) system in real time. Five volunteers (one laryngectomee and four normal speakers) participated in the experimental evaluation of the method and SGVS-EL system. Using ANN participants were able to perform high vowel precision with identification rates of >90% after the training. The results of voicing control indicated that all subjects using SGVS-EL could achieve good vowel control performance in real time, but still control errors frequently occurred at the voice initiation period. However, the control errors had no significantly impact on the perception of SGVS-EL speech. Intelligibility evaluation demonstrated that both the vowels and words produced using the SGVS-EL were more intelligible than vowels spoken with a commercial EL (by 30%) or words (by 18%), respectively. Using a controlled vowel-specific voice source was a feasible and effective way to improve EL speech quality with more intelligible words.

We developed a novel artificial larynx with on/off and pitch control for Speech Production Substitutes (SPSs) users, particulary an electrolarynx control based on the myoelectric signal of the laryngeal muscles located near the body surface (such as the sternohyoideus). For patients who have lost their vocal cords or its function for vocalization, various SPSs have been developed and widely used. However, these substitutes have the limitation -that they cannot match with the vocalization of healthy human larynx. The measurement of the surface myoelectric potential was performed and we studied its efficiency for voice on/off and pitch frequency control. The results show that there is a quadratic relation between the measured myoelectric potential and the pitch frequency. Using this relation, it was possible to control the pitch frequency of the generated sound in three levels with 86.7% of accuracy (condition of linear relationship lead 68.9%). This confirms that the surface myoelectric potential was a suitable control signal for the artificial larynx. In this paper, the capability of novel controllable artificial larynx controlled by myoelectric signal of sternohyoideus was described.

An electrolarynx (EL) is a medical device that generates sound source signals to provide laryngectomees with a voice. In this article we focus on two problems of speech produced with an EL (EL speech). One problem is that EL speech is extremely unnatural and the other is that sound source signals with high energy are generated by an EL, and therefore, the signals often annoy surrounding people. To address these two problems, in this article we propose three speaking-aid systems that enhance three different types of EL speech signals: EL speech, EL speech using an air-pressure sensor (EL-air speech), and silent EL speech. The air-pressure sensor enables a laryngectomee to manipulate the F"0 contours of EL speech using exhaled air that flows from the tracheostoma. Silent EL speech is produced with a new sound source unit that generates signals with extremely low energy. Our speaking-aid systems address the poor quality of EL speech using voice conversion (VC), which transforms acoustic features so that it appears as if the speech is uttered by another person. Our systems estimate spectral parameters, F"0, and aperiodic components independently. The result of experimental evaluations demonstrates that the use of an air-pressure sensor dramatically improves F"0 estimation accuracy. Moreover, it is revealed that the converted speech signals are preferred to source EL speech.

Objective In Hong Kong, esophageal (SE), tracheoesophageal (TE), electrolaryngeal (EL), and pneumatic artificial laryngeal (PA) speech are commonly used by laryngectomees as a means to regain verbal communication after total laryngectomy. While SE and TE speech has been studied to some extent, little is known regarding the EL and PA sound quality. The present study examined the sound quality associated with SE, TE, EL, and PA speech, and compared with that associated with laryngeal (NL) speech by using long-term average speech spectra (LTAS). Methods Continuous speech samples of reading a 136-word passage were obtained from NL, SE, TE, EL, and PA speakers of Cantonese. The alaryngeal speakers were all superior speakers selected from the New Voice Club of Hong Kong, which is a self-help organization for the laryngectomees in Hong Kong. TE speakers were fitted with Provox valve, and EL speakers used Servox-type electrolarynx. Speech samples were digitized at 20 kHz and 16 bits/sample by using Praat, based on which LTAS contours were developed. First spectral peak (FSP), mean spectral energy (MSE), and spectral tilt (ST) derived from the LTAS contours associated with different speaker groups were compared. Results Data revealed all speakers generally exhibited similar LTA contours. However, PA speakers exhibited the lowest average FSP value and the greatest average MSE value. NL phonation was associated with a significantly greater ST value than alaryngeal speech of Cantonese. Conclusion The differences in FSP, MSE, and ST values in different speaker groups may be related to the different sound sources being used by the laryngectomees, and the difference in the way the sound source is coupled with the vocal tract system.

Three individuals with total laryngectomy were studied for their ability to control a hands-free electrolarynx (EL) using neck surface electromyography (EMG) for on/off and pitch modulation. The laryngectomy surgery of participants was modified to preserve neck strap musculature for EMG-based EL control (EMG-EL), with muscles on one side maintaining natural innervation and those on the other side receiving a transferred recurrent laryngeal nerve (RLN). EMG from each side of the neck controlled the EMG-EL across a day of unstructured practice followed by a day of formal training, including EMG biofeedback. Using either control source, participants spoke intelligibly and fluently with the EMG-EL before formal training. This good initial performance did not consistently improve across testing for either control source in terms of voice timing, speech intelligibility, fluency, and intonation of interrogative versus declarative sentences. Neck strap muscles have activation patterns capable of simple alaryngeal voice control without requiring RLN transfer. Learning outcomes: The reader will better understand (1) functionality of the hands-free electrolarynx (2) modification of laryngectomy surgery to preserve neck strap musculature and (3) performance of hands-free electrolarynx with different control sources.

In normal speech, coordinated activities of intrinsic laryngeal muscles suspend a glottal sound at utterance of voiceless consonants, automatically realizing a voicing control. In electrolaryngeal speech, however, the lack of voicing control is one of the causes of unclear voice, voiceless consonants tending to be misheard as the corresponding voiced consonants. In the present work, we developed an intra-oral vibrator with an intra-oral pressure sensor that detected utterance of voiceless phonemes during the intra-oral electrolaryngeal speech, and demonstrated that an intra-oral pressure-based voicing control could improve the intelligibility of the speech. The test voices were obtained from one electrolaryngeal speaker and one normal speaker. We first investigated on the speech analysis software how a voice onset time (VOT) and first formant (F1) transition of the test consonant-vowel syllables contributed to voiceless/voiced contrasts, and developed an adequate voicing control strategy. We then compared the intelligibility of consonant-vowel syllables among the intra-oral electrolaryngeal speech with and without online voicing control. The increase of intra-oral pressure, typically with a peak ranging from 10 to 50 gf/cm2, could reliably identify utterance of voiceless consonants. The speech analysis and intelligibility test then demonstrated that a short VOT caused the misidentification of the voiced consonants due to a clear F1 transition. Finally, taking these results together, the online voicing control, which suspended the prosthetic tone while the intra-oral pressure exceeded 2.5 gf/cm2 and during the 35 milliseconds that followed, proved efficient to improve the voiceless/voiced contrast.

Objective: Patients of laryngeal cancer who have undergone the surgical removal of the entire larynx suffer the loss of phonation. Electrolarynx (EL) speech is the most commonly adopted alaryngeal phonation. However, EL speech is notorious of the sound quality being monotonic and robotic with the lack of pitch control and the presence of the radiated noise. This paper provides a review of modalities in EL speech as well as introducing the technologies to control the pitch and reduce the noise of the device. Methods: Improvements of EL speech quality have been divided into two parts: improving the sound quality of EL device by applying different enhancement algorithms to reduce the radiated and the additive noise, and implementing pitch-control function to the EL with advanced technology. Results: Adaptive filtering and the subtractive-type algorithms have shown to be able to reduce the noise level associated with EL speech. And more mature technologies are showing promise to the making of a hand-free EL system producing more accurate and synchronized pitch and voice onset control. Conclusion: The advent of micro-technology and human-machine integration promisingly improves EL speech quality and more efficient algorithms enhanceEL soundquality. Suchimprovementsapparently improvethe intelligibility of ELspeech, and thusbetter quality oflife of the EL speakers. # 2007 Elsevier Ireland Ltd. All rights reserved.

This study investigated the relationship among the magnitude of jaw opening, intrinsic fundamental frequency (F0), and glottal parameters in natural speech. Acoustic, jaw opening, and electroglottographic (EGG) signals were simultaneously recorded. The subjects were 10 healthy men with New Zealand English as their native language. Subjects were asked to repeat a standard nonemphasized sentence in which one of the target vowels (/a/, /e/, /i/, /o/, and /u/) was embedded in various contexts. The glottal parameters F0, open quotient (OQ), and speed quotient (SQ) were measured from the EGG signal. Results of a series of one-way repeated-measures analyses of variance (ANOVA) showed a significant vowel effect on the magnitude of jaw opening [F(4, 24) = 25.512, P.001], F0 [F(4, 28) = 45.415, P.001] and speed quotient [F(4, 28) = 5.233, P = .003], but not on the open quotient [F(4, 28) = 0.501, P = .735]. The magnitude of jaw opening was found to be inversely related with F0 (r = -0.624, n = 25, P = .0009). These findings showed that the magnitude of jaw opening was related to F0 and that jaw opening might be a control signal for simulation of long-term F0 variation to achieve a higher degree of naturalness in artificial voice.

We developed and evaluated an intra-oral electrolaryngeal speech aid system for those who could not acquire common alaryngeal speech or for early post-surgery speech rehabilitation. Our system consisted of a denture-base intra-oral vibrator, a wireless miniature fingertip switch and a controller. To produce natural speech, the fingertip switch produced binary commands of voicing and accent and the controller implemented the pitch generation model using the commands. We first estimated the intelligibility of consonant–vowel syllables produced by our system. We then obtained the feedback about the system from the Japanese users on the basis of their daily life use, and evaluated the possibility and acceptability as an alaryngeal speech aid. Although the users were less satisfied at the intra-oral electrolarynx, the intelligibility of the intra-oral electrolarygeal speech was comparable to that of transcervical electrolaryngeal speech, and most of them were willing to employ it if they lost their current electrolaryngeal speech. According to the feedbacks from the users, a completely wire-free system and less eye-catching designs would make the prosthesis more acceptable. These results placed the intra-oral electrolarynx as a useful option of alaryngeal speech aids and encouraged the further development of the intra-oral electrolarynx.

This clinical report describes the clinical requirements, treatment sequence, and use of a relatively new intraoral electrolarynx for a completely edentulous patient. This device consists of a sound source attached to the maxilla and a hand-held controller unit that controls the pitch and volume of the intraoral sound source via transmitted radio waves.

Since the first reports of laryngectomy surgery, voice preservation has been an important consideration in planning treatment and developing improved methods. General acceptance of laryngectomy for the management of laryngeal cancer demands a realistic chance of voice preservation. The most frequently quoted paper describing the first successful laryngectomy reported Billroth’s operation and proposed a fistula technique for voice restoration [1]. The procedure used a pharyngostoma to manage secretions and an external device to direct exhaled air into the pharynx for voice production. By the late 19th century, the pharyngostoma was no longer part of the laryngectomy procedure, making it more acceptable, but voice rehabilitation required the development of esophageal speech or an external device to provide vibrating air for phonation. A number of pneumatic or electrical devices became available for voice. The most effective was esophageal speech, which freed the laryngectomee from devices and provided an ‘‘internal’’ voice from the patient’s natural pharyngoesophageal tissues, often called the pseudoglottis. The acquisition of esophageal speech requires dedicated training, and depends on the development of the pseudoglottis after laryngectomy, which is never a planned part of the procedure. For these reasons, less than one third of laryngectomees acquire esophageal speech, and only a few are considered exceptional speakers. Thus, many patients are relegated to unnaturalsounding external devices, writing pads, or silence. Alternatively, with the development of clinical radiation therapy techniques, treatment of many laryngeal cancers by a nonsurgical method is more acceptable to patients and medical colleagues. This preference for nonsurgical management of laryngeal cancer is the basis for today’s organ-preservation protocols. The recurring and

Modern esophageal reconstruction usually achieved satisfactory results. Vocal reconstruction and rehabilitation, however, are still far from perfect. Fortunately, they are being improved progressively. Tracheo-esophageal puncture with a voice prosthesis, neoglottis, and voice tube shunts can be applied in addition to esophageal voice, artificial larynx, and various voice devices. With the possibility of vocal restoration, patients are more ready to accept laryngectomy when it is necessary. In the meantime, surgeons are more radical in tumor ablation so as to minimize the possibility of local recurrence.

The contraction of the stapedius muscle during the effort of vocalization was examined by measurement of acoustic compliance in subjects who had undergone laryngectomy or tracheostomy. No significant level of persistent compliance change was recorded in any of the subjects, indicating the absence of effective contraction of the stapedius during the vocalization effort. In two subjects who use an electrolarynx, although no significant compliance change resulted from the simple vocalization effort without the electrolarynx (no actual vocalized sound), a remarkable level of persistent compliance change was observed during the vocalization using the electrolarynx. These results seem to indicate that a simple vocalization effort without actual voice cannot elicit effective contraction of the middle ear muscles, and that sound generation during vocalization is essential for effective contraction of the middle ear muscles during vocalization, at least in some human subjects.

OBJECTIVE: The purpose of the current study was to evaluate the characteristics of vibroacoustic devices used for fetal stimulation. STUDY DESIGN: Intrauterine sound pressure levels over a frequency range of 40 to 5000 Hz were measured with hydrophones in anesthetized sheep. Stimulators included the AT&T (Martinsburg, W.V.) and Servox (Hearing Instruments, Piscataway, N.J.) artificial larynges, the Corometrics fetal acoustic stimulator (Wallingford, Conn.) and an electric toothbrush. RESULTS: Intrauterine spectral patterns resulting from stimulation with the AT&T, Servox, and Corometrics devices were characterized by numerous high-level overtones above a fundamental frequency between 97 and 163 Hz. Fundamental frequencies recorded during toothbrush stimulation were 22 to 24 Hz with reduced but identifiable overtones up to 250 Hz. CONCLUSIONS: Fetal vibroacoustic stimulators that operate on the principle of the electronic artificial larynx produce very similar intrauterine sound pressure levels.

We measured the effects of 2 minutes of vibroacoustic stimulation on the activity of unanesthetized fetal sheep in utero. We were unable to detect any changes in activity after stimulation with a model 5C electrolarynx. With more powerful stimulation using a mechanical oscillator, fetal electrocortical activity desynchronized. Fetal breathing and eye movements changed with electrocortical activity and there was an increase in nuchal muscle activity. Stimulation caused a small decrease in fetal heart rate. Responses to stimulation were not seen in four of the five fetuses with bilateral cochlear ablation. These results indicate that in fetal sheep the auditory apparatus is necessary for the detection of vibroacoustic stimuli. The difference in responsiveness of the sheep and human fetus appears to be because of a difference in central processing after detection of the stimulus.

Laryngectomized patients using esophageal speech or an electronic artificial larynx have difficulty producing correct voicing contrasts between homorganic consonants. Voicing of a voiceless consonant is the most frequent listener misidentification. A therapy technique is described that emphasizes “pushing harder” on voiceless consonants to improve the intelligibility of alaryngeal speakers. Laryngectomy speech therapy programs should focus first on the production of voiceless consonants before attempting to effect voicing.

This project was a perceptual investigation of contrastive stress in alaryngeal speech. The ability to signal contrastive stress in American English was assessed by obtaining high quality tape recordings of sentence production from four normal and sixteen laryngectomized speakers using four different types of alaryngeal speech. The recordings of these sentences, paired on the basis of differences in the location of contrastive stress, were presented to forty listeners for perceptual evaluation of stress location using a two-interval-forced-choice procedure. As expected, the four normal speakers achieved high (95% or above) levels of stress contrast. Contrastive stress patterns were also realized in a highly effective manner (93% or above) by three esophageal speakers, three tracheoesophageal (Blom-Singer) speakers, and three users of the Western Electric # 5 artificial larynx. Contrastive stress patterns were realized in a lower (86–88%), but reasonably effective manner by two users of the Servox artificial larynx. The findings were interpreted to highlight the contributions that study of clinical samples may make to questions about linguistic theory, speech production and speech perception.

Of 103 people with the clinical diagnosis of laryngeal cancer studied by the authors, 53 eventually were treated by total laryngectomy and, in some cases, radical neck dissection (43), preoperative radiation therapy (15), postoperative radiation therapy (29), and post-operative chemotherapy (7). All were entered into a comprehensive rehabilitation program. Six months following completion of their cancer therapy 47 were re-evaluated. Of these, 12 (26 per cent) used esophageal speech as the dominant mode of communication, 16 (34 per cent) the electrolarynx, and the remainder either wrote (16 [34 per cent]) or signed (3 [6 per cent]). Twenty-six (55 per cen) were considered to be successfully) rehabilitated overall and 21 (45 per cent) were not. These data indicate that the rehabilitative needs of today's laryngectomee are not being met successfully with traditional methods.

The need to train alaryngeal speakers to use increased vocal intensity has been noted in the literature. One untested technique is to evoke an intensity increase by applying masking noise to the ears of the talker. The purpose of this study was to investigate the Lombard effect on the speech of esophageal talkers, artificial larynx users, and normal speakers. The subjects read aloud a variety of materials first in quiet then while being subjected to 100 dB SPL noise delivered through earphones. The resulting sound pressure values were obtained by measuring the peak values of all syllables spoken by each talker. The results indicated that the esophageal talkers produced the highest intensity increase in the noise condition followed by the normal talkers and the artificial larynx talkers. Coarticulatory and duration effects on alaryngeal and normal speech are also reported. Clinical implications are discussed.

Twenty-eight normal hearing and speaking listeners rated the intelligibility and acceptability of speech produced by a laryngectomized patient using five different electronic artificial larynx devices. Analysis of variance indicated significant differences among the artificial larynx devices, but these differences were dependent upon the listener's task and the syntactical complexity of the speech.

The purpose of this investigation was to compare the proficiency ratings made by laryngectomee and nonlaryngectomee judges when evaluating videotaped samples of laryngeal and alaryngeal speakers. A group of laryngectomee judges and three groups of nonlaryngectomized judges completed proficiency ratings for the following speakers: (1) laryngeal ( n =10); (2) electrolarynx ( n =11); (3) esophageal ( n =12); and (4) tracheoesophageal puncture ( n =10). Significant differences between laryngectomee and nonlaryngectomee judges were found when rating alaryngeal speakers, but not when rating normal, laryngeal speakers. Differences in judge group ratings varied according to the voicing method of the speakers and according to the vocal parameter being rated.

Prosthetic rehabilitation of a severely incapacitated cancer patient has been described. When the total cervical larynx, trachea, and esophagus have been lost, the problem of saliva entrapment must be dealt with by a device that will prevent aspiration of the oral fluids. A definitive esophageal prosthesis was designed which allowed the patient to enjoy a reasonably normal diet and again taste her food. At a later time, an artificial larynx was fitted, which enabled the patient to live at home in a fairly normal manner.

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We evaluated the effectiveness of the electrolarynx as a communication tool in the short-term hospital setting with 22 tracheostomized patients. Following an initial training period, we found that 14 of 22 patients achieved good results in communicating with the electrolarynx, three patients had fair results, and five patients had poor results. There were no differences in success rates for older or younger patients or for men or women; we could not correlate specific disease diagnosis with success or failure. The instrument could be effectively cleaned at the bedside. With the exception of patients who are severely confused or who have undergone extensive head and neck surgery, all tracheostomized patients can be considered candidates for this method of communication.