Imme Roesner

Towards Objective Voice Assessment: The Diplophonia Diagram.

OBJECTIVES Diplophonia is an often misinterpreted symptom of disordered voice, and needs objectification. An audio signal processing algorithm for the detection of diplophonia is proposed. Diplophonia is produced by two distinct oscillators, which yield a profound physiological interpretation. The algorithms performance is compared with the clinical standard parameter degree of subharmonics (DSH). STUDY DESIGN This is a prospective study. METHODS A total of 50 dysphonic subjects with (28 with diplophonia and 22 without diplophonia) and 30 subjects with euphonia were included in the study. From each subject, up to five sustained phonations were recorded during rigid telescopic high-speed video laryngoscopy. A total of 185 phonations were split up into 285 analysis segments of homogeneous voice qualities. In accordance to the clinical group allocation, the considered segmental voice qualities were (1) diplophonic, (2) dysphonic without diplophonia, and (3) euphonic. The Diplophonia Diagram is a scatter plot that relates the one-oscillator synthesis quality (SQ1) to the two-oscillator synthesis quality (SQ2). Multinomial logistic regression is used to distinguish between diplophonic and nondiplophonic segments. RESULTS Diplophonic segments can be well distinguished from nondiplophonic segments in the Diplophonia Diagram because two-oscillator synthesis is more appropriate for imitating diplophonic signals than one-oscillator synthesis. The detection of diplophonia using the Diplophonia Diagram clearly outperforms the DSH by means of positive likelihood ratios (56.8 versus 3.6). CONCLUSIONS The diagnostic accuracy of the newly proposed method for detecting diplophonia is superior to the DSH approach, which should be taken into account for future clinical and scientific work.

Summarized institutional experience of paediatric airway surgery

OBJECTIVES The management of paediatric airway stenosis is complex, and requires a dedicated team, consisting of thoracic surgeons, phoniatricians, logopaedics, paediatricians and anaesthetists. The majority of paediatric laryngotracheal stenosis is a sequela of prematurity and prolonged post-partal intubation/tracheostomy. Surgical correction is often difficult due to a frequent combination of glottic and subglottic defects. METHODS In 2012, the Laryngotracheal Program Vienna was launched. Since then, 18 paediatric patients were surgically treated for (laryngo-)tracheal problems. RESULTS The median age of our patients was 26 months (range 2-180 months). Laryngotracheal stenosis extending up to the level of the vocal cords was evident in 9 patients. Three children were diagnosed with an isolated subglottic, and four with a short-segment tracheal stenosis or malacia. Two patients had a long-segment congenital malformation together with vascular ring anomalies. Five children were pretreated by rigid endoscopy before surgical correction, 12 of our 18 patients had a tracheostomy, 3 children were intubated at the time of operation. Different techniques of corrections were applied: laryngotracheal reconstruction (n = 4), extended partial cricotracheal resection (n = 4), cricotracheal resection with or without anterior split or dorsal mucosal flap (n = 4), slide tracheoplasty (n = 2), tracheal resection (n = 4). In 8 patients, a rib cartilage interposition was necessary in order to obtain a sufficient lumen enlargement and in 7 of these patients, an LT-Mold was placed to stabilize the reconstruction. We lost 2 patients, who were referred to our institution after failure of multiple preceding interventions, 2 and 3 months after the operation. Twelve patients are currently in an excellent condition, one is in an acceptable condition without a need for an intervention. Two patients required an endoscopic reintervention 18 and 33 months after the operation, 1 child is currently still cannulated. CONCLUSIONS Paediatric airway surgery is complex, and requires a dedicated interdisciplinary team. An armamentarium of different resection and reconstruction techniques is necessary in order to achieve good long-term results.

Diplophonia Disturbs Jitter and Shimmer Measurement

Objectives: The aims of this study are to investigate the effects of diplophonia on jitter and shimmer and to identify measurement limitations with regard to material selection and clinical interpretation. Materials and Methods: Four hundred and ninety-eight audio samples of sustained phonations were analyzed. The audio samples were assessed for the grade of hoarseness and the presence of diplophonia. Jitter and shimmer were reported with regard to perceptual ratings. We investigated cycle marker positions exemplarily and qualitatively to understand their implications for perturbation measurements. Results: Medians of jitter and shimmer were higher for diplophonic voices than for nondiplophonic voices with equal grades of hoarseness. The variance of jitter for moderately dysphonic voices was larger than the variance observed in a corpus from which diplophonic samples had been discarded. The positions of cycle markers in diplophonic voices did not match the positions of the pulses, indicating that the validity of jitter and shimmer values for these voices were questionable. Conclusion: Diplophonia biases the reporting of dysphonia severity via perturbation measures, and their validity is questionable for these voices. In addition, diplophonia is an influential source of variance in jitter measurements. Thus, diplophonic fragments of voice samples should be excluded prior to perturbation analysis.

A modified technique of laryngotracheal reconstruction without the need for prolonged postoperative stenting

OBJECTIVES Repair of laryngotracheal stenosis with pronounced side-to-side narrowing and involvement of the glottis is challenging and usually requires laryngotracheal reconstruction with rib cartilage interpositions. This technique, as first described by Couraud, needs prolonged postoperative stabilization with Montgomery T-tubes, imposing significant morbidity and discomfort on patients. We describe our initial experience with a modified laryngotracheal reconstruction technique that avoids the need for prolonged postoperative stenting. METHODS From November 2012 through May 2015, a series of 5 adult patients with glottosubglottic stenosis were operated in our institution. All patients had pronounced scar formation in combination with advanced side-to-side narrowing extending up to the level of the vocal folds. Operative technique consisted of a complete anterior and posterior laryngeal split followed by rib cartilage interposition in the cricoid plate posteriorly to enlarge the glottosubglottic diameter. The lateral edges of the rib graft were trimmed in such a way that lateral flanges were created, which allowed stable positioning of the graft. The distal trachea was then slid into the larynx, and the posterior defect was completely covered with a liberal membranous flap. The anterior part of the larynx was enlarged with a V-shaped segment of the anterior tracheal wall. RESULTS This technique provided immediate stability without the need for temporary endoluminal stenting. The perioperative course was uneventful in all patients, and functional outcome was excellent. CONCLUSIONS We conclude that this modified technique of laryngotracheal reconstruction represents a valid treatment option for patients with complex glottosubglottic stenosis, avoiding the need for prolonged postoperative stenting.

Fundamental frequency tracking in diplophonic voices

Abstract Background and objectives Fundamental frequency ( f o ) extraction in disordered voices is a prerequisite for many types of clinical analyses. Special attention must be paid if multiple oscillators with different f o s are active simultaneously. Two independent approaches to f o tracking in diplophonic voices are proposed and compared with a benchmark from the literature. Material and methods Six samples of sustained phonations were analyzed. High-speed videos were obtained in addition to audio recordings. Video-based f o tracks were obtained from cycle marks that report maximal vocal fold deflection in digital kymograms. Audio waveform modeling based extraction involved candidate tracking, oscillator waveform synthesis and track selection. Audio subband auto-correlation based extraction served as a benchmark. Results and discussion Promising qualitative and quantitative agreement of audio waveform modeling based estimates with kymogram-based tracks was observed. With reference to the kymogram-based tracks, audio waveform modeling based extraction had a median total error rate of 1.9%, which is an improvement over the benchmark method (17.7%). Conclusion The results illustrate that f o s of diplophonic voices may be validly obtained from kymogram cycle marks, as well as via audio waveform modeling. The acquisition of two simultaneous f o tracks in diplophonic voices may increase the validity of clinical voice analysis procedures in the future.

Comparison of an audio-based and a video-based approach for detecting diplophonia

Abstract Background and objectives Diplophonia is a common symptom in voice disorders. Depending on the underlying aetiology, diplophonic patients typically need treatment such as phonosurgery or speech therapy. In current clinical practice, the presence of diplophonia is assessed by auditive rating. To avoid subjectivity in voice assessment and to follow principles of evidence based medicine, objective instrumental assessment methods are needed. In order to gain insight into instrumental assessment of diplophonic voice, comparisons between different assessment approaches are necessary. The aim of the study is to compare the performance of two independent objective approaches on their ability to detect diplophonia. The compared approaches are the formerly published degree of subharmonics (DSH), and a newly proposed measure for spatial bimodality of the vocal fold vibration. Material and methods From a clinical database of 352 laryngeal high-speed videos with synchronous audio recordings, 60 phonation segments (20 euphonic, twenty diplophonic and twenty non-diplophonic dysphonic) were auditively selected. For all phonation segments, the DSH and the newly proposed measure for spatial bimodality were determined. The DSH is the occurrence rate of audio analysis blocks with ambiguous fundamental frequency in percent. The bimodality measure quantifies the spatial occurrence of secondary oscillation frequencies along the vocal folds’ edges. Both the DSH and the bimodality measure are evaluated on their ability to detect diplophonia by means of cut off threshold classification. Results and conclusions The DSH showed excellent classification rates for separating diplophonic from euphonic phonation (sensitivity: 98.4%, specificity: 100%). In separating diplophonic from non-diplophonic dysphonic phonation, the bimodality measure slightly outperforms the DSH approach (sensitivity: 54.6%, specificity: 92.7%). The separation of diplophonia from other kinds of dysphonia is challenging, and more sophisticated methods are needed. It is concluded that auditive and glottal diplophonia must be distinguished. As the clinical assessment of diplophonia primarily aims at determining glottal conditions, the video-based approach might deliver clinically more relevant data than the auditive approach.

Pre-emptive glottic enlargement before laryngotracheal surgery in patients at high risk for postoperative bilateral vocal fold paralysis†

OBJECTIVES Bilateral vocal fold paralysis (VFP) is a severe complication after laryngotracheal (LT) surgery. The reduced glottic opening leads to significant respiratory distress immediately after the operation and requires the placement of a tracheostomy in most cases. Patients with a pre-existing unilateral VFP or expected recurrent nerve resection are at the highest risk for glottic failure. These patients might benefit from a pre-emptive glottic enlargement before LT surgery. METHODS We performed a retrospective review of patients who received a pre-emptive glottis enlargement before LT surgery at the Medical University of Vienna from October 2011 to December 2016. Peri- and postoperative outcomes of this strategy were analysed. RESULTS Six patients underwent preparatory glottic enlargement prior to LT resection. Four patients had recurrent thyroid cancer, and 1 patient had thymic cancer invading the cervical airway. The remaining patient had a complex benign glotto/subglottic stricture complicated by a pre-existing bilateral VFP. All patients received oblique cricotracheal resections extending into the larynx [resection length 39 ± 7 mm (mean ± SD)]. Extubation within 24 h after surgery was achieved in 5 of 6 cases, although all patients had postoperative unilateral (n = 5) or bilateral (n = 1) VFP as anticipated. In 5 of the 6 patients, oral intake could be started immediately after the operation. The remaining patient regained full swallowing function after intensive swallowing rehabilitation. Postoperative voice quality was subjectively perceived as satisfactory by all patients. CONCLUSIONS Pre-emptive glottic enlargement is a valuable treatment strategy in patients at highest risk for postoperative bilateral VFP. It facilitates immediate postoperative extubation, despite at least unilateral VFP and extensive LT surgical procedures.

Assessment of nasalance and nasality in patients with a repaired cleft palate

In patients with a repaired cleft palate, nasality is typically diagnosed by speech language pathologists. In addition, there are various instruments to objectively diagnose nasalance. To explore the potential of nasalance measurements after cleft palate repair by NasalView®, we correlated perceptual nasality and instrumentally measured nasalance of eight speech items and determined the relationship between sensitivity and specificity of the nasalance measures by receiver-operating characteristics (ROC) analyses and AUC (area under the curve) computation for each single test item and specific item groups. We recruited patients with a primarily repaired cleft palate receiving speech therapy during follow-up. During a single day visit, perceptive and instrumental assessments were obtained in 36 patients and analyzed. The individual perceptual nasality was assigned to one of four categories; the corresponding instrumental nasalance measures for the eight specific speech items were expressed on a metric scale (1–100). With reference to the perceptual diagnoses, we observed 3 nasal and one oral test item with high sensitivity. However, the specificity of the nasality indicating measures was rather low. The four best speech items with the highest sensitivity provided scores ranging from 96.43 to 100%, while the averaged sensitivity of all eight items was below 90%. We conclude that perceptive evaluation of nasality remains state of the art. For clinical follow-up, instrumental nasalance assessment can objectively document subtle changes by analysis of four speech items only. Further studies are warranted to determine the applicability of instrumental nasalance measures in the clinical routine, using discriminative items only.