Decrease In F0 Research Articles

Effects of Laryngeal Manual Therapy on Primary Muscle Tension Dysphonia (MTD-1): Implications for MTD-1 Type

The study investigated effects of laryngeal manual therapy on different types of primary muscle tension dysphonia (MTD-1). Interventional pre-test post-test design. Thirty-two traditional Iranian singers (mean age of 36.75 ± 9.34 years.) diagnosed with MTD-1, 8 female and 24 male, and recruited by convenience sampling completed the study. MTD-1 was classified as Morrison and Rammage's types 1-5, based on standardized criteria (1993). Pre-post-treatment measures were based on visual ratings of the larynx, acoustic analyses, auditory-perceptual assessments of voice (Auditory-Perceptual Rating Instrument for Operatic Singing Voice: EAI Scale Form), and the Persian Singing Voice Handicap Index (P-SVHI), reported before and after 10 sessions of laryngeal manual therapy (LMT). The most notable finding was that the number of cases with MTD-1 types 1 and 2 actually increased after treatment, while the number of cases with MTD-1 types 3, 4 and 5 decreased. The data suggested that MTD-1 types 3, 4, and 5 tended to convert to types 1 and 2 with LMT. Acoustic analyses showed a significant decrease in F0 (males only; P=0.011), a sharp decrease in HNR from 23.26 dB to 14.74 dB (P=0.000), and an increase in shimmer from 4.18% to 6.90 % while no appreciable change was found in jitter (P=0.57). Mean P-SVHI score decreased significantly from 52.03 to 41.16 (P=0.002) and EAI score increased from 4.41 to 6.31 (P=0.000) after treatment. The primary finding was that the distribution of MTD-1 type changed after treatment in many cases, converting from one to another type. Acoustic as well as glottal closure measures for several participants revealed closure insufficiency after treatment, unveiled as hyperfunction was unloaded with LMT. For those participants, complementary treatments aimed at reinforcement of laryngeal closure functions would be appropriate.

Immediate Effects of Semi-occluded Vocal Tract Exercises as a Vocal Warm-Up in Singers

The present study aimed to investigate the Immediate Effects of Semi-occluded Vocal Tract Exercises (SOVTEs) as a vocal warm-up on the Electrical Activity of Extrinsic Laryngeal Muscles and acoustic parameters of voice in singers. This study used a pre-/post-interventional (quasi-experimental) design and a simple non-random sampling method. Musculoskeletal Rehabilitation Research Center. Surface electromyography of the suprahyoid and infrahyoid muscle areas and acoustic measurements were assessed before and immediately after performing three SOVTEs: lip-trill, humming, and straw phonation for 20 minutes as a vocal warm-up in eleven healthy male singers with an average age of 26.5 ± 4.2. After performing the vocal warm-up, root mean square in channels two and three (left and right infrahyoid muscle areas) in all vocal tasks, including /i/, /u/, and counting from 20 to 30 was significantly decreased (P < 0.05). The acoustic parameters, F1, and F1-F0 difference were significantly decreased (P < 0.05). The results suggest that after performing SOVTEs as a vocal warm-up, the electrical activity of the extrinsic laryngeal muscles is reduced. The acoustic analysis also demonstrated a decrease in F0, F1, and F1-F0 variables. Therefore, it seems that the results of acoustic and electromyographic assessments are in line and it is likely that SOVTEs through the vocal economy lead to a reduction in the load applied to the phonatory system.

Application of High Speed Digital Imaging (HSDI) technique and voice acoustic analysis in the diagnosis of the clinical form of Presbyphonia in women.

&lt;b&gt;Introduction:&lt;/b&gt; The aging process of voice begins after the age of 60 and has an individually variable course. Voice quality disorders at this age are called senile voice (Presbyphonia or Vox Senium). Voice pathology is particularly severe in women. The aim of the study was to diagnose the clinical form of Presbyphonia in elderly women using High Speed Digital Imaging (HSDI) and acoustic voice analysis. &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt; Study included 50 elderly women (average age 69) with dysphonia (Group I). Control group (Group II) included 30 women (average age 71) without voice quality disorders. Visualization assessment has been conducted with High Speed Digital Imaging (HSDI) with High Speed camera (HS). Acoustic evaluation of voice included analysis isolated vowel "a" and continuous linguistic text with Diagnoscope Specialista software. Maximum Phonation Time (MPT) has been determined. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; In Group I, 78% of women revealed vocal folds vibrations asymmetry, vibration amplitude increase, Mucousal Wave (MW) limitation and Type D glottal insufficiency (GTs). Acoustic voice analysis proved decrease in F0, increase in Jitter, Shimmer, NHR. In 22% of women, next to vibrations asymmetry, vibration amplitude reduction and MW limitation, Type E glottal insufficiency (GTs) have been found. Acoustic voice analysis revealed slight decrease in F0 and the presence of numerous non-harmonic components in the glottis region. &lt;br&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Vocal folds visualization with HSDI showed edema, less often atrophy in elderly women. Both forms of dysphonia were caused abnormal values of F0, Jitter, Shimmer, NHR in the acoustic voice evaluation and significant reduction of MPT.

A Longitudinal Ageing Analysis of Vocal Parameters of Singing Voice of Female Playback Singer

Age-related changes to the vocal structure affect the singing ability of the singer. We present a longitudinal study of vocal ageing of a female professional playback singer having more than six decades of singing span (covering singer age from 19 to 80 years). The ageing analysis is performed on six vocal parameters like – fundamental frequency (F0), vibrato, formants and spectral features like spectral roll-off and centroid. Statistical variations in these vocal parameters over the entire singing span of the singer are discussed in the paper. Significant effects noted with the ageing voice were - decrease in F0, decreased vocal range, reduction in vibrato rate, increase in vibrato extent, decrease in F2 &amp; F4 formants and rapid change in the spectral features. This investigation also studied the effect of ageing on singing voice quality through the measurement of singing power ratio (SPR). Increase in SPR measures was observed with ageing voice. The study of impact of vocal ageing with longitudinal data on singer identification (SID) is scare. The SID experimentation performed with 350 cappella songs covering entire singing span of the singer, showed a clear impact that change in acoustical parameters with ageing affected the performance of singer identification systems.

Force-Velocity-Power Profiling During Weighted-Vest Sprinting in Soccer

Purpose: To describe the load-velocity relationship and the effects of increasing loads on spatiotemporal and derived kinetic variables of sprinting using weighted vests (WV) in soccer players and determining the load that maximizes power output. Methods: A total of 23 soccer players (age 20.8 [1.5]y) performed 10 maximal 30-m sprints wearing a WV with 5 different loads (0%, 10%, 20%, 30%, and 40% body mass [BM]). Sprint velocity and time were collected using a radar device and wireless photocells. Mechanical outputs were computed using a recently developed valid and reliable field method that estimates the step-averaged ground-reaction forces during overground sprint acceleration from anthropometric and spatiotemporal data. Raw velocity-time data were fitted by an exponential function and used to calculate the net horizontal ground-reaction forces and horizontal power output. Individual linear force-velocity relationships were then extrapolated to calculate the theoretical maximum horizontal force (F0) and velocity and the ratio of force application (proportion of the total force production that is directed forward at sprint start). Results: Magnitude-based inferences showed an almost certain decrease in F0 (effect size = 0.78-3.35), maximum power output (effect size = 0.78-3.81), and maximum ratio of force (effect size = 0.82-3.87) as the load increased. The greatest changes occurred with loads heavier than 20% BM, especially in ratio of force. In addition, the maximum power was achieved under unloaded conditions. Conclusions: Increasing load in WV sprinting affects spatiotemporal and kinetic variables. The greatest change in ratio of force happened with loads heavier than 20% BM. Thus, the authors recommend the use of loads ≤20% BM for WV sprinting.

Analysis of voice quality parameters in patients with vestibular voice.

Vestibular voice includes participation of larynx structures which are absent in physiological process. Vestibular phonation may be desired when vocal folds are damaged as in paralytic dysphonia, or undesired in marginal hyperfunction. Vestibular voice may result from psychogenic dysphonia - phononeurosis. The aim of the study is perceptive evaluation of vestibular voice, objective larynx visualization, acoustic and aerodynamic examination. The study included 40 patients: 20 with vestibular voice, 20 with euphonic voice. Voice quality has been evaluated using perceptual GRBAS scale. Endoscopic and stroboscopic larynx examination used Endo-STROB-EL-Xion GmbH with visual tract. High-Speed Digital Imaging (HSDI) and High Speed (HS) camera registered true vocal folds vibrations. Acoustic evaluation of voice with DiagnoScope Specjalista, DiagNova Technologies included analysis of F0, Jitter, Shimmer, NHR, nonharmonic components. MPT has been analyzed. In examined group, hoarseness (95%), roughness (75%) and voice strain (55%) have been recorded. Endoscopy revealed edema of vestibular folds with dilation of vessels covering glottis. Stroboscopy and HSDI confirmed coexistence of hyperfunctional (95%) or paralytic (5%) dysphonia. Acoustic assessment revealed increase in Jitter, Shimmer, NHR and decrease in F0 and MPT. The vestibular voice is observed most frequently in women with hyperfunctional dysphonia (phononeuroses) or in paralytic dysphonia. Visualization techniques confirm the coexistence of vestibular folds hypertrophy and edema with vibration disorders. In the perceptual assessment, vestibular voice was hoarse, rough and strained. Acoustic examination showed increase of Jitter, Shimmer, NHR, presence of nonharmonic components and decrease of F0 and MPT.

Establishment and Analysis of False Vocal Folds Hypertrophy Model in Excised Canine Larynges

This study aimed to investigate the role of false vocal folds (FVFs) medialization in phonation and the acoustic impact of ventricular hypertrophy by establishing an FVF hypertrophy model. A prospective in vitro experiment was carried out. The study was carried out using a pseudolung platform with high-speed camera in a soundproof room. Control, degree I, and degree II FVFs hypertrophy were simulated in 10 excised larynges via fructose injection of 0.1 mL for degree I and 0.25 mL for degree II. Mean flow rate (MFR), fundamental frequencies (F0), formants, and sound pressure level were measured with a subglottal pressure of 1.5 kPa and 2.5 kPa, respectively. When the subglottal pressure was controlled at both at 1.5 kPa and at 2.5 kPa, the degree of FVF hypertrophy significantly influenced the distribution of the formants, F0, and MFR in excised canine larynges. Increasing the degree of hypertrophy was associated with a decrease in F0 and an increase in MFR. In degree II FVF hypertrophy models, the sound pressure level and the first formant were significantly higher (P < 0.05) than in normal models. Hypertrophy of the FVFs has a significant influence on the distribution of sound energy and is associated with changes in sound quality.

Interactions of subglottal pressure and neuromuscular activation on fundamental frequency and intensity.

Fundamental frequency (F0) and intensity sound pressure level (SPL) of voice are controlled by intrinsic laryngeal muscle (ILM) activation and subglottal pressure (Psub). Their interactions were investigated. In an in vivo canine model, the thyroarytenoid (TA), lateral cricoarytenoid/interarytenoid (LCA/IA), and cricothyroid (CT) muscles were independently activated from threshold to maximal contraction by neuromuscular stimulation in various combinations, whereas airflow was increased to phonation onset pressure and beyond. The resultant acoustic output was analyzed for effects of Psub on vibratory stability, F0, and SPL. Muscle activation plots and vocal range profiles by individual ILM activation states were analyzed. Cricothyroid activation increased phonation onset F0, but vibration was less stable in high CT conditions and displayed vibratory mode change. In addition, a decrease in F0 with increased Psub was observed in high CT conditions. Intensity increased with Psub in all conditions, but the slope was greater at high CT, low TA/LCA/IA activations. Lateral cricoarytenoid/interarytenoid activation improved vocal efficiency. To maintain same F0 with increasing SPL (messa di voce), TA activation was decreased and LCA/IA activation was increased. The same F0 and SPL could be achieved with a variety of ILM activation combinations. Cricothyroid is primarily required for increasing F0, whereas TA can increase or decrease F0 and SPL. Lateral cricoarytenoid/interarytenoid activation likely maintains vocal fold adduction during increased Psub and improves vocal efficiency. This study also demonstrates laryngeal motor equivalence, the ability of the larynx to achieve the same target F0 and SPL with multiple combinations of ILM activation. N/A. Laryngoscope, 126:1123-1130, 2016.

Normative study of vocal acoustic parameters from children from 4 to 12 years of age without vocal symptoms. A pilot study

Acoustic vocal analysis is a simple and fast method that allows to differentiate normal from changed voices. There are few studies that analyze normal acoustic vocal parameters at different age ranges in children. AimsTo establish normative acoustic parameters of children's voice aged 4 to 12 years. MethodsTwo hundred and forty children were divided into four sub-groups by age: G1 (n-60; 4-5 years), G2 (n-60; 6-7 years), G3 (n-60; 8-9 years) and G4 (n-60; 10-12 years). The children's parents answered a questionnaire and the children were submitted to auditory acuity evaluation (Assessment of Transient Otoacoustic Emissions), acoustic vocal analyses, otorhinolaryngological and videolaryngoscopy exams. ResultsThe normal values for the acoustic vocal parameters studied were established according to age range and gender. As age increased, there was a decrease of f0 and APQ and an increased in SPI with statistical difference of these parameters. The vocal parameters did not differ between genders until the age of 12. Conclusionsthe characterization of the normative vocal patterns of children is an important reference for future studies. Some of the changes showed a direct relationship between age and a reduction of f0 and of APQ, and increase in SPI, with no difference between genders.

Transgenerational inheritance of heart disorders caused by paternal bisphenol A exposure

Bisphenol A (BPA) is an endocrine disruptor used in manufacturing of plastic devices, resulting in an ubiquitous presence in the environment linked to human infertility, obesity or cardiovascular diseases. Both transcriptome and epigenome modifications lie behind these disorders that might be inherited transgenerationally when affecting germline. To assess potential effects of paternal exposure on offspring development, adult zebrafish males were exposed to BPA during spermatogenesis and mated with non-treated females. Results showed an increase in the rate of heart failures of progeny up to the F2, as well as downregulation of 5 genes involved in cardiac development in F1 embryos. Moreover, BPA causes a decrease in F0 and F1 sperm remnant mRNAs related to early development. Results reveal a paternal inheritance of changes in the insulin signaling pathway due to downregulation of insulin receptor β mRNAs, suggesting a link between BPA male exposure and disruption of cardiogenesis in forthcoming generations.

Voice Disorders in Teachers: Clinical, Videolaryngoscopical, and Vocal Aspects

Dysphonia is more prevalent in teachers than among the general population. The objective of this study was to analyze clinical, vocal, and videolaryngoscopical aspects in dysphonic teachers. Ninety dysphonic teachers were inquired about their voice, comorbidities, and work conditions. They underwent vocal auditory-perceptual evaluation (maximum phonation time and GRBASI scale), acoustic voice analysis, and videolaryngoscopy. The results were compared with a control group consisting of 90 dysphonic nonteachers, of similar gender and ages, and with professional activities excluding teaching and singing. In both groups, there were 85 women and five men (age range 31-50 years). In the controls, the majority of subjects worked in domestic activities, whereas the majority of teachers worked in primary (42.8%) and secondary school (37.7%). Teachers and controls reported, respectively: vocal abuse (76.7%; 37.8%), weekly hours of work between 21 and 40 years (72.2%; 80%), under 10 years of practice (36%; 23%), absenteeism (23%; 0%), sinonasal (66%; 20%) and gastroesophageal symptoms (44%; 22%), hoarseness (82%; 78%), throat clearing (70%; 62%), and phonatory effort (72%; 52%). In both groups, there were decreased values of maximum phonation time, impairment of the G parameter in the GRBASI scale (82%), decrease of F0 and increase of the rest of acoustic parameters. Nodules and laryngopharyngeal reflux were predominant in teachers; laryngopharyngeal reflux, polyps, and sulcus vocalis predominated in the controls. Vocal symptoms, comorbidities, and absenteeism were predominant among teachers. The vocal analyses were similar in both groups. Nodules and laryngopharyngeal reflux were predominant among teachers, whereas polyps, laryngopharyngeal reflux, and sulcus were predominant among controls.

Developmental changes in the fundamental frequency (f0) of infants’ cries: a study of children with Autism Spectrum Disorder

Episodes of crying with higher fundamental frequency (f0) are perceived as more aversive and distressful than lower frequency cries. Besides, previous studies have speculated that in children with Autism Spectrum Disorder (ASD) higher f0 may account for evoking mental states of uneasiness in the caregiver. Moreover no evidence on developmental trajectory of f0 in ASD in infancy is present in literature. This research investigated: developmental trajectory of f0 of episodes of crying in children with ASD as opposed to typically developing (TD) children and children with other developmental delay (DD). Two studies were employed. In Study 1, using a standardised protocol for acoustic analysis a group of 30 TD children was followed longitudinally (five, 13 and 20 months) and f0 of their episodes of crying was analysed. In Study 2, acoustic analysis was applied to episodes of crying selected from retrospective home videos of 30 children with ASD, TD and DD at five and 18 months. Decrease of f0 in TD children between the first and second year both using a standard procedure and the retrospective procedure was found. Besides while in TD and DD children a change of the f0 trajectory was present, no changes were evident in ASD. Higher f0 may account in ASD for a caregiver bias in their interpretation of crying, evoking mental states of uneasiness and it may interfere with the adequacy of the parental response. Limitations and future goal of the research are described.

Acoustic Voice Analysis of Prelingually Deaf Adults Before and After Cochlear Implantation

It is widely accepted that many severe to profoundly deaf adults have benefited from cochlear implants (CIs). However, limited research has been conducted to investigate changes in voice and speech of prelingually deaf adults who receive CIs, a population well known for presenting with a variety of voice and speech abnormalities. The purpose of this study was to use acoustic analysis to explore changes in voice and speech for three prelingually deaf males pre- and postimplantation over 6 months. The following measurements, some measured in varying contexts, were obtained: fundamental frequency (F0), jitter, shimmer, noise-to-harmonic ratio, voice turbulence index, soft phonation index, amplitude- and F0-variation, F0-range, speech rate, nasalance, and vowel production. Characteristics of vowel production were measured by determining the first formant (F1) and second formant (F2) of vowels in various contexts, magnitude of F2-variation, and rate of F2-variation. Perceptual measurements of pitch, pitch variability, loudness variability, speech rate, and intonation were obtained for comparison. Results are reported using descriptive statistics. The results showed patterns of change for some of the parameters while there was considerable variation across the subjects. All participants demonstrated a decrease in F0 in at least one context and demonstrated a change in nasalance toward the norm as compared to their normal hearing control. The two participants who were oral-language communicators were judged to produce vowels with an average of 97.2% accuracy and the sign-language user demonstrated low percent accuracy for vowel production.

Tornadoes from Squall Lines and Bow Echoes. Part I: Climatological Distribution

Abstract The primary objective of this study was to estimate the percentage of U.S. tornadoes that are spawned annually by squall lines and bow echoes, or quasi-linear convective systems (QLCSs). This was achieved by examining radar reflectivity images for every tornado event recorded during 1998–2000 in the contiguous United States. Based on these images, the type of storm associated with each tornado was classified as cell, QLCS, or other. Of the 3828 tornadoes in the database, 79% were produced by cells, 18% were produced by QLCSs, and the remaining 3% were produced by other storm types, primarily rainbands of landfallen tropical cyclones. Geographically, these percentages as well as those based on tornado days exhibited wide variations. For example, 50% of the tornado days in Indiana were associated with QLCSs. In an examination of other tornado attributes, statistically more weak (F1) and fewer strong (F2–F3) tornadoes were associated with QLCSs than with cells. QLCS tornadoes were more probable during the winter months than were cells. And finally, QLCS tornadoes displayed a comparatively higher and statistically significant tendency to occur during the late night/early morning hours. Further analysis revealed a disproportional decrease in F0–F1 events during this time of day, which led the authors to propose that many (perhaps as many as 12% of the total) weak QLCSs tornadoes were not reported.

Long‐term half‐hourly measurement of soil CO2 concentration and soil respiration in a temperate deciduous forest

We conducted a field experiment in a cool‐temperate deciduous forest to investigate the dynamic behavior of soil CO2 and the vertical distribution of soil respiration. Soil CO2 concentration (C) was measured half‐hourly at four depths for 6 months in 2000 with infrared gas analyzers installed below ground. Using C profiles, soil surface CO2 efflux (F0), CO2 production rates of the topsoil (PA), and CO2 flux from the subsoil to topsoil (FCA) were evaluated half‐hourly by applying Fick's first law. Some remarkable short‐term and long‐term variations were found in C, F0, PA, FCA, and the contribution of topsoil respiration to total soil respiration (PA/F0), which include (1) rapid increase in C and decrease in F0 and PA due to rainwater infiltration, (2) diurnal variation in C coupled with that of the atmosphere, (3) diurnal variation in F0 and PA similar to that of topsoil temperature, (4) decrease in C, F0, and PA following soil drying in August, (5) linearly increasing FCA between late May and mid‐September, and (6) decrease in PA/F0 from around 0.9 during summer to 0.3 in November. The variation of PA was mainly controlled by soil temperature at −0.07 m between 7° and 17°C, although PA did not respond well to soil temperature above and below this temperature range. Above 17°C, PA increased linearly with soil moisture, and moisture variation accounted for the PA decrease in August. Neither temperature nor moisture explained the PA behavior below 7°C. Subsoil respiration (FCA) showed an exponential relationship with soil temperature at −1 m.

The Effect of Photoautotrophy on Photosynthesis and Photoinhibition of Gardenia Plantlets during Micropropagation

We studied the relationships between the degree of photoautotrophy, photosynthetic capacity, and extent of photoinhibition of Gardenia jasminoides Ellis plantlets in vitro. Two successive micropropagation stages (shoot multiplication and root induction), and three culture conditions [tube cap closure, photosynthetic photon flux density (PPFD), and sucrose concentration] which may influence the development of photoautotrophy in vitro were assayed. The ratios of variable chlorophyll fluorescence to either maximal (Fv/Fm) or ground (Fv/F0) values were low, irrespective of the culture stage or growing conditions. Incomplete development of the photosynthetic apparatus and permanent photoinhibition may be involved. However, Fv/Fm and Fv/F0 increased from shoot multiplication to root induction owing to a decrease in F0 and an increase in Fm. This suggests that photoinhibition decreases later during micropropagation, when the photoautotrophy of plantlets is more advanced. The low sucrose content and high PPFD increased the photoinhibition of plantlets, whereas growth in tubes with permeable caps showed the opposite effect. The only culture factor with a significant (positive) effect on maximum photosynthetic rate (Pmax) was PPFD. At shoot multiplication net photosynthetic rate (PN) was positively correlated with the half time of the increase from F0 to Fm (t1/2). Such association may be mainly due to a common response of both traits to higher PPFD in culture. Within each culture stage, no relationship was observed between PN and the degree of photoautotrophy, which was positively correlated with Fv/Fm and Fv/F0 during root induction. During shoot multiplication, these correlations were not significant, or were even negative. Hence during the last stage of micropropagation, plantlets with a higher degree of photoautotrophy are less photoinhibited, whereas they do not follow this pattern at the earlier stage.

The effect of partially restored hearing on speech production of postlingually deafened adults with multichannel cochlear implants.

The effect of auditory feedback on speech production was investigated in five postlingually deafened adults implanted with the 22-channel Nucleus device. Changes in speech production were measured before implant and 1, 6, and 24 months postimplant. Acoustic measurements included: F1 and F2 of vowels in word-in-isolation and word-in-sentence context, voice-onset-time (VOT), spectral range of sibilants, fundamental frequency (F0) of word-in-isolation and word-in-sentence context, and word and sentence duration. Perceptual ratings of speech quality were done by ten listeners. The significant changes after cochlear implantation included: a decrease of F0, word and sentence duration, and F1 values, and an increase of voiced plosives' voicing lead (from positive to negative VOT values) and fricatives' spectral range. Significant changes occurred until 2 years postimplant when most measured values fell within Hebrew norms. Listeners were found to be sensitive to the acoustic changes in the speech from preimplant to 1, 6, and 24 months postimplant. Results suggest that when hearing is restored in postlingually deafened adults, calibration of speech is not immediate and occurs over time depending on the age-at-onset of deafness, years of deafness, and perception skills. The results also concur with hypothesis that the observed changes of some speech parameters are an indirect consequence of intentional changes in other articulatory parameters.

Acoustic characteristics in 6-10-year-old children's voices: some preliminary findings

This study investigates the vocal characteristics in a group of 20 children aged 6-, 8- and 10-years old as a function of age and sex. Fundamental frequency (F0) and its variability were measured. Results suggested that the female children showed a steady decrease in F0 between the ages of 6 and 10 years and that the male children showed a marked decrease in F0 between the ages of 8 and 10 years. There was also decreased variability in F0. The first four formant frequencies (F1?F4 in Hz) and their corresponding formant bandwidths (B1?B4 in Hz) were measured for the phrase-final vowel. These data indicated significant age and sex differences for F1?F3. Sex differences were also found for B1 and age differences were found for B2 and F4. The results are also indicative of the development and maturation in the vocal apparatus.

Osmotic and Atmospheric Dehydration Effects in the Lichens Hypogymnia Physodes, Lobaria Pulmonaria, and Peltigera Aphthosa: An in vivo Study of the Chlorophyll Fluorescence Induction

Inactivation of photosynthesis during atmospheric and osmotic (highly concentrated NaCl or sucrose solutions) dehydration was monitored by measurement of chlorophyll fluorescence induction (OIP-phase, Kautsky-curves) in three lichen species. The induction curves were changed in a very similar way by all three treatments. All dehydration effects were rapidly reversible after rehydration. At relatively mild water stress, the rise time to the transient peak Fp was prolonged, and the variable part of fluorescence was diminished. In addition, at severe water stress, a considerable decline of the F0 value was observed. For NaCl treatment this effect started at water potentials <-8.5 MPa in P. aphthosa, <-12 MPa in H. physodes, and <-21 MPa in L. pulmonaria. Above these water potentials, our observations are in agreement with values from desiccation-tolerant algae, higher plants, and lichens, where an inactivation on the photosystem 2 (PS2) donor side has been postulated. At very low water potentials, the decrease in F0 probably monitors changes in the organization of the antenna apparatus of PS2.

Fundamental frequency during phonetically governed devoicing in normal young and aged speakers

Age-related changes in the laryngeal system can be perceived as altered vocal pitch and increased pitch variability. However, reports vary as to the nature and extent of an age effect on fundamental frequency (F0) for analyses taken over long segments of connected speech. Analysis of F0 across a smaller time frame may be more informative. Young speakers show an increase in F0 associated with phonetically governed devoicing gestures that is likely mediated by increased vocal fold stiffness. Anatomic and neurophysiologic changes in the aged larynx may limit the role of increased vocal fold stiffness in the devoicing gesture. This study tests the hypothesis that aged speakers show a smaller increase in F0 in association with the devoicing gesture for production of an intervocalic voiceless obstruent than do young speakers. Normal young and aged speakers produced a short sentence containing an intervocalic voiceless obstruent. Measures of F0 were obtained for ten cycles before voice offset and ten cycles after voice onset. Young speakers showed a small increase in F0 during devoicing whereas aged speakers showed a decrease in F0 during devoicing. Aged speakers seem to rely more on vocal fold abduction rather than a combination of abduction and tensing to achieve devoicing.