The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitude of effect on the EGG short-term spectrum was estimated for each of these conditions. It was found that the short-term spectrum of the EGG signal sufficed to discriminate between different phonatory configurations, such as modal and falsetto voice. It was found also that even supposedly purely articulatory changes could be traced in the spectrum of the EGG signal. Finally, possible pedagogical and clinical applications of the method are discussed. / <p>QC 20140609</p> / FonaDyn

Larynxcancer är den tredje vanligaste formen av huvud- och halscancer och drabbar cirka 175 personer årligen i Sverige. En vanlig behandlingsmetod vid larynxcancer är strålbehandling. Detta är en retrospektiv journalstudie med syfte att undersöka hur svälj- och röstfunktion samt nutritionsstatus påverkas av strålbehandling för larynxcancer. Studiens syfte är även att undersöka om det finns något samband mellan tumörgrad och sväljförmåga efter avslutad behandling samt om och när svälj- och röstfunktion återhämtas. Studien har även undersökt andelen patienter som erbjudits logopedkontakt. I studien har 52 patienter med larynxcancer (C.32) inom region Gävleborg inkluderats. Resultaten indikerar att strålbehandling påverkar svälj- och röstfunktion samt nutritionsstatus. Vid strålavslut hade 24 av 48 patienter tecken på sväljsvårigheter och 33 av 52 patienter hade en påverkan på röstfunktionen. Under behandlingen noterades ett ökat behov av näringsdryck och 24 av 37 deltagare gick ner i vikt under eller efter behandling vilket indikerar nutritionssvårigheter. Andelen patienter som var i behov av enteral nutrition vid strålavslut var 7 av 52 patienter. Sammanlagt erbjöds 33 av 52 patienter logopedkontakt. Återhämtning av sväljfunktionen rapporterades hos 22 av 39 patienter inom ett år efter avslutad strålbehandling. Återhämtning av röstfunktionen noterades hos 8 av 40 patienter inom fem år efter avslutad strålbehandling. Studiens resultat ger värdefull information om strålbehandlingens påverkan på livsviktiga funktioner och hoppas kunna bidra med underlag till prospektiva studier inom huvud- och halscancer. / Laryngeal cancer is the third most common form of head- and neck cancer and each year approximately 175 people receive the diagnosis in Sweden. Radiotherapy is a common treatment against laryngeal cancer. This is a retrospective cohort study, and it has investigated how swallowing, voice function and nutritional status can be affected by radiotherapy. The aim of the study was to explore whether there is a correlation between the grade of tumor and swallowing after treatment and when swallowing and voice function recover. The aim was also to research how many patients received contact with a speech- and language pathologist before or during treatment. The following study included 52 patients with laryngeal cancer (C.32) within the region of Gävleborg, Sweden. The results indicate that radiotherapy affects swallowing, voice function, and nutritional status. By the end of treatment, 24 of 48 patients had signs of dysphagia and voice function was affected in 33 of 52 patients. An increase in the need for nutritional drinks was noted throughout radiotherapy and 24 of 37 patients lost weight during or after treatment, which indicates nutritional difficulties. At the end of the treatment, 7 of 52 patients needed enteral nutrition. In total, 33 of 52 patients were offered contact with a speech- and language pathologist. Recovery of the swallowing function was reported in 22 of 39 patients at some point during the first year after radiotherapy. Recovery of voice function was reported in 8 of 40 patients at some point during five years after radiotherapy. The results of the study indicates possible implications that radiotherapy might have on vital functions, and it can suffice as a basis for further prospective studies within the area of head- and neck cancer.