Objective Acoustic Analysis Research Articles

Multiparameter Voice Assessment for Voice Disorder Patients: A Correlation Analysis Between Objective and Subjective Parameters

The aim of this study was to establish a multiparameter voice assessment profile using objective multiparameter test and subjective voice quality assessment. We assessed 50 patients with voice disorders before and after operation. The assessment incorporates (1) subjective voice quality assessment, (2) patients' self-assessment, and (3) objective acoustic analysis. The subjective voice quality assessment uses GRABS system to evaluates the grade of hoarseness (G), proposed by the Japanese Society for Logopedics and Phoniatrics. Patients' self-assessment is modified based on the Chinese version of voice handicap index (VHI) scale, composed of functional (F), physiological (P), emotional (E) part, and a total score (T). The acoustical analysis evaluate the patients' voice sample by voice analysis software "Dr. Speech". Three parameters, jitter (J), shimmer(S), and normalized noise energy (NNE), were taken in analysis. We observed high correlations among subentries F, P, and the total score TvH of the VHI scale in patients' subjective assessment. Parameter E does not correlate well with other assessed parameters. The Chinese version ofVHI, which incorporate multifactors including age, education, and especially the cultural difference may account for the inconsistent correction in parameter E. In the objective acoustic analysis, high correlation among the three parameters J, S, and NNE is observed. Systemic assessment combining a subjective voice quality assessment, an objective acoustic analysis, and a self-assessment is helpful in clinical practice in the diagnosis and treatment for voice disorders. The E component in VHI scale assessment may not be a reliable parameter to evaluate treatment outcome.

Characteristics and occurrence of speech impairment in Huntington’s disease: possible influence of antipsychotic medication

Although motor speech impairment is a common manifestation of Huntington's disease (HD), its description remains limited. The aim of the current study was therefore to estimate the occurrence and characteristics of speech disorder in HD and to explore the influence of antipsychotic medication on speech performance. Speech samples, including reading passage and monologue, were acquired from 40 individuals diagnosed with HD and 40 age- and sex-matched healthy controls. Objective acoustic analyses were used to evaluate key aspects of speech including vowel articulation, intensity, pitch and timing. A predictive model was constructed to detect the occurrence and most prominent patterns of speech dysfunction in HD. We revealed that 93% of HD patients manifest some degree of speech impairment. Decreased number of pauses, slower articulation rate, imprecise vowel articulation and excess intensity variations were found to be the most salient patterns of speech dysfunction in HD. We further demonstrated that antipsychotic medication may induce excessive loudness and pitch variations perceptually resembling excess patterns of word stress, and may also accentuate general problems with speech timing. Additionally, antipsychotics induced a slight improvement of vowel articulation. Specific speech alterations observed in HD patients indicate that speech production may reflect the pathophysiology of the disease as well as treatment effects, and may therefore be considered a valuable marker of functional disability in HD.

Ocena jakości głosu po usunięciu nowotworów T1 i T2 głośni z jednoczesną rekonstrukcją fałdu głosowego uszypułowanym płatem z mięśnia mostkowo-tarczowego

IntroductionIn recent years there has been an increasing number of cases of cancer, including cancer of the larynx. The choice of treatment should be primarily dictated by the complete elimination of cancer, but from the point of view of the patient, an important factor to keep in mind, is the quality of the voice that will be created at the end of the therapeutic process. AimThe aim of this study was to evaluate the voice quality of patients after partial surgery of the larynx with vocal fold reconstruction pedunculated sterno-thyroid muscle flap. Materials and MethodsThe study included 30 men aged 53–72 years who were treated at the Clinic of Otorhinolaryngology Department of Medical-Dental Medical University of Warsaw on account of cancer of the larynx, qualified according to the TNM classification T1 or T2. The radical removal of cancer was associated with resection of one vocal fold, laryngeal pouches and ventricular fold. In 15 patients, included to the group I at the end of phase oncology surgery, a reconstruction of “vocal fold” pedunculated sterno-thyroid muscle flap were performed simultaneously. The group II consisted of 15 patients who underwent surgery that removed only the cancerous lesions. Impact assessments arising after surgery of voice disorders on quality of life were made using the self-test failure of the voice (Voice Handicap Index in the Pruszewicz modification). The nature of the created voice was studied using GRBAS scale. All patients performed the laryngostroboscope examination. With “IRIS” program, prepared by a team at Wrocław University of Technology, the voice was recorded, and then was subjected to acoustic analysis. In addition, noise level and the maximum phonation time was measured. ResultsThe results indicate that the patients of group I gained a better voice confirming the values of objective acoustic analysis. The assessment made by the scale GRBAS patients who supplemented the resulting loss after tumour removal, with much less hoarseness of voice, did not have the hyperkinesis and there was no puff character. They had the better flow of voice and phonation time of vowels “a” was much longer. The assessment of quality of life of patients in group I made in a test of the VHI was higher than in group II. The laryngostroboscope examination confirmed a good phonatory occlusion and a nearly regular, healthy vocal fold vibration in patients who had received flap of muscle. ConclusionsEvaluation of the quality of voice after removing the tumor multiplicity in the glottis with simultaneous reconstruction “vocal fold” has confirmed that this is a very good surgical technique, which allows radically curing cancer for the simultaneous preservation of a good voice. The operation has limited indications for radiotherapy because of the desire to preserve the phonatory function of the larynx, and thus avoids the negative effects of radiation.

Vocal therapy of hyperkinetic dysphonia.

Hyperkinetic (hyperfunctional) dysphonia is a common pathology. The disorder is often found in vocal professionals faced with high vocal requirements. The objective of this study was to evaluate the effects of vocal therapy on voice condition characterized by hyperkinetic dysphonia with prenodular lesions and soft nodules. The study included 100 adult patients and 27 children aged 4-16 years with prenodular lesions and soft nodules. A subjective acoustic analysis using the GIRBAS scale was performed prior to and after vocal therapy. Twenty adult patients and 10 children underwent objective acoustic analysis including several acoustic parameters. Pathological vocal qualities (hoarse, harsh and breathy voice) were also obtained by computer analysis. The subjective acoustic analysis revealed a significant (p<0.01) reduction in all dysphonia parameters after vocal treatment in adults and children. After treatment, all levels of dysphonia were lowered in 85% (85/100) of adult patients and 29% (29/100) had a normal voice. Before vocal therapy 9 children had severe, 13 had moderate and 8 slight dysphonia. After vocal therapy only 1 child had severe dysphonia, 7 had moderate, 10 had slight levels of dysphonia and 9 were without voice disorder. The objective acoustic analysis in adults revealed a significant improvement (p≤0.025) in all dysphonia parameters except SD FO and jitter %. In children, the acoustic parameters SD FO, jitter % and NNE (normal noise energy) were significantly improved (p=0.003-0.03). Pathological voice qualities were also improved in adults and children (p<0.05). Vocal therapy effectively improves the voice in hyperkinetic dysphonia with prenodular lesions and soft nodules in both adults and children, affectinq diverse acoustic parameters.

Acoustic analysis of voice in children with cochlear implants

Introduction. The focus of this study was the analysis of objective acoustic characteristics of voice in children with cochlear implants. The objective of this study was to compare acoustic parameters of voice in children with cochlear implants and normal hearing children of the same age, and to determine differences, if there were any. Material and Methods. There were 60 children (aged from 6 to 13) included in this prospective study. They were divided into 2 groups: children with cochlear implants (30) and normal hearing children with normal speech development (30). The most stable voice sample was analyzed using a software program Dr Speech: Vocal Assessment. Objective acoustic analysis of voice included 13 acoustic parameters. Results. Standard deviation of fundamental frequency was significantly (p=0.000) higher in children with cochlear implants, as well as the values of harmonic to noise ratio (p=0.003) and signal to noise ratio (p=0.000) parameters. Values of jitter %, shimmer %, normalized noise energy, fundamental frequency tremor and amplitude tremor showed no significant differences between the two groups. However, the values of parameters that refer to voice frequency (habitual fundamental frequency, mean fundamental frequency, min fundamental frequency and max fundamental frequency) and the mean value of voice intensity (p=0.004), were significantly higher in the boys and the girls with cochlear implants than in the normal hearing children. Conclusion. Gender non-related parameters of hoarseness did not show significant differences between the children with cochlear implants and the normal hearing children; the results of cochlear implantation and voice and speech education were therefore positive. However, the children with cochlear implants of both gender showed significantly higher values of voice intensity, voice pitch and insufficient control of voice pitch variation.

Pourazowe zmiany krtani i głosu u dzieci

Summary The larynx trauma – this is about 7% of all cases of post traumatic changes in human body. The most useful classification from clinical point of view is external and internal traumas. In children even due to relative resistance of larynx on external trauma, they are not rare. Material of our paper consists children of age 12, 11 and 16 after various laryngeal trauma. Respectively there were traumatic changes after multiple bronchoscopy and lungs cysts operation, laryngeal malformation after dog bits in neck region and larynx trauma in car accident. In all cases the first symptom was dyspnea and then dysphonia. The purpose of the paper was to introduce the results of voice rehabilitation in specific post traumatic structural malformations of larynx. The voice estimation based on perceptual and objective acoustic analyses in comparison on glottis morphology. There was found that the voice quality not always depends on extension and degree of larynx damage.

Jakość głosu u górników po urazie inhalacyjnym górnych dróg oddechowych w wyniku wybuchu metanu

The job as a coal-miner exposes to the great risk. One of the most dangerous health hazard is a burn/inhalation injury during the methane explosion. The victims undergo physical trauma, effect of high temperature and inhalation of toxic gases and products of incomplete combustion. As a result of inhalation injury both, upper and lower airways are affected. The aim of the study was to analyse the relationship between burn/inhalation injury and quality of voice in affected coal-miners. A group of 23 patients (men) in age from 28 to 59 (mean 38.5) 3 years after burn/inhalation injury participated in this study. The voice evaluation based on ENT examination, videlaryngostroboscopy, acoustic analysis, MPT parameter and GRBAS analysis was performed. The special control group of coal-miners served as a control. On the basis of the subjective evaluation and the objective acoustic analysis, aerodynamic parameter and videlaryngostroboscopy the worse quality of voice in the group of injured coalminers was shown in comparison to the control group. No substantial correlation between the acoustic parameters, MPT parameter and ventilating rates was found.

Functional voice and swallowing outcomes after robotic thyroidectomy by a gasless unilateral axillo-breast approach: comparison with open thyroidectomy

Voice and swallowing alterations are common complaints after thyroidectomy, even in the absence of laryngeal nerve impairment. However, voice and swallowing functions after robotic thyroidectomy have not been thoroughly investigated. This study compared the functional outcomes for voice and swallowing after robotic thyroidectomy and conventional open thyroidectomy. The study prospectively analyzed the voice and swallowing functions of patients with thyroid nodules who underwent robotic thyroidectomy by a gasless unilateral axillo-breast (GUAB) approach (50 cases) or by conventional open thyroidectomy (61 cases) from September 2009 to October 2010. Videolaryngostroboscopy or flexible laryngoscopy was performed pre- and postoperatively. Subjective voice and swallowing alterations were assessed by questionnaire preoperatively and then 1 day, 1 week, 1 month, 3 months, and 6 months postoperatively. In addition, objective acoustic voice analysis was performed using a Multidimensional Voice Program, with Voice Range Profiles and maximum phonation times measured preoperatively and then 1 week, 1 month, 3 months, and 6 months postoperatively. Subjective postoperative voice function was significantly better in the robotic group at 1 day, 1 month, and 3 months postoperatively than in the open group. The mean values of fundamental frequency, jitter, shimmer and noise-to-harmonic ratio before and after surgery did not differ between the two groups. However, the frequency range and the highest frequency were significantly better in the robotic group than in the open group at 3 months postoperatively. Subjective swallowing function did not differ between the two groups. Postoperative voice function is better with robotic thyroidectomy using the GUAB approach than with conventional open thyroidectomy. This is an advantage of robotic thyroidectomy by the GUAB approach in addition to the excellent cosmesis.

Vocal therapy with larynx compression after partial laryngectomy

The aim of the study was to establish the effects of the vocal therapy by manual compression of the larynx on dysphonia due to a partial laryngectomy and compare them with the effects of the standard vocal therapy. The prospective study included 66 patients submitted to any partial laryngectomy type. The patients were randomly classified into two groups: Group I (33) receiving the standard vocal therapy, and Group II (33) submitted to larynx compression vocal therapy. The 6-week vocal treatment was performed. The treatment effects were evaluated by subjective and objective voice analysis methods. The subjective and objective acoustic voice analysis revealed a significant influence (p < 0.05) of either of the two vocal therapy modes on initial dysphonia. The larynx compression vocal therapy had better effects on the acoustic parameters: habitual fundamental frequency, mean fundamental frequency, standard deviation of fundamental frequency, maximal fundamental frequency, harmonics-to-noise ratio, and signal-to-noise ratio.

Impact of anterior single-tooth implants on quality of life, articulation and oromyofunctional behaviour: a pilot study

The main purpose of this study is to determine the impact (one and a half year after implantation) of a single-tooth implant on articulation and oromyofunctional behaviour. This information is important for dentists, orthodontists or stomatologists who treat professional speakers. Objective (acoustic analysis) as well as subjective (questionnaire, phonetic inventory, phonetic analysis, oromyofunctional assessment of lip and tongue function, blowing, sucking and swallowing) assessment techniques were used to determine the quality of life, articulation and oromyofunctional behaviour. Fourteen subjects who received a single-tooth implant and a control group of nine subjects participated in this study. The mean overall satisfaction of single-implant users was 95%. The subjects who received a single-tooth implant were capable of producing all Dutch vowels and consonants. The phonetic analysis revealed a sigmatism in 57% of the cases. Sigmatisms (stridens sigmatism followed by simplex sigmatism) were the most frequently observed phonetic disorders. There was interobserver agreement about normal lip and tongue functions. Moreover, blowing, sucking and swallowing patterns were normal (concordance value 96%). Detailed analyses 1 or 2 years after implantation of an anterior single-tooth implant revealed normal speech intelligibility and oromyofunctional behaviour. Articulation was characterised by the presence of a persistent phonetic disorder. Further research involving more subjects with an anterior single-tooth implant is needed.

Objective acoustic analysis of voice improvement after phonosurgery

To evaluate voice improvement after phonosurgery by objective acoustic analysis. This prospective study was conducted in Maulana Azad Medical college New Delhi from December 2002 to 2008. In this study 100 subjects were included comprising of all age groups and either sex. All these patients with organic voice disorder underwent speech analysis using VAUGMI speech analysis program before and after phonosurgery. All the parameter of voice analysis were deranged before the treatment but after surgery all the parameters should improvement most significant change was seen in the jitter. After doing this study we found that the analysis of hoarse voice using various parameters of acoustic analysis like fundamental frequency, harmonics to noise ratio, jitter, shimmer, S/z ratio helped us in identifying the degree of hoarseness and the severity related to it. Some parameters like jitter and shimmer were able to detect the component of hoarseness in perceptually normal voice and thus patient was helped by doing surgery and voice therapy at the appropriate time.

A total building performance approach to evaluating building acoustics performance

Acoustic comfort is an important consideration in the design and construction of office buildings. Since the acoustic performance of a building will affect its inhabitants psychologically, sociologically and physiologically, post-occupancy evaluations of acoustic performance are often necessary to ensure that acoustic design features are effective. Since acoustic quality is often affected by the interplay among the building's interior, structural, envelope and mechanical systems, it is critical to assess acoustic quality in an integrated manner. This article presents a detailed acoustic evaluation of a three-storeyed office building by adopting a total building performance (TBP) approach. Through plan/archive analysis, expert walkthrough, objective acoustic measurements and analysis, the existing acoustic problems are identified. Subjective views of occupants regarding acoustic quality in the office and warehouse spaces are also sought. It was found that both objective and subjective data support each other. By understanding how these problems are caused by the interactions among the different building systems, specific solutions were proposed. In summary, this work highlights the usefulness of using a TBP concept to diagnose the acoustic quality of a multi-storeyed office building in an integrated manner. This project is motivated by an effort to promote workplace comfort and sustainability within the framework of corporate social responsibility.

Objective Acoustic Analysis of Pathological Voices from Patients with Vocal Nodules and Polyps

Objective: We aim to examine the abilities of objective acoustic analysis methods (nonlinear dynamic and traditional perturbation measures) to describe voices from individuals with vocal nodules and polyps. Subjects and Methods: Sustained vowel recordings from normal subjects, patients with vocal nodules, and patients with vocal polyps were analyzed. Perturbation measures of jitter and shimmer were obtained with the Multi-Dimensional Voice Program (MDVP) and CSpeech. Signal-to-noise ratio was calculated using CSpeech. Nonlinear dynamic measures of phase space reconstruction and correlation dimension were also applied to analyze the voices. Results: A significant difference between normal and polyp groups was found in jitter and shimmer obtained from MDVP, as well as in jitter and signal-to-noise ratio from CSpeech. However, no parameters significantly differentiated between normal and nodule groups. Shimmer from CSpeech did not reveal any significant differences among any of the groups. Correlation dimension values for the nodule and polyp groups were significantly higher than the normal group. Conclusion: Nonlinear dynamic analysis has great potential value for the characterization of voice from patients with vocal nodules and polyps. The combination of traditional perturbation and nonlinear dynamic measures may improve our ability to provide objective clinical analysis of voices with vocal mass lesions.

Objective Voice Changes in Nondysphonic Parkinson's Disease Patients

To obtain objective acoustic analysis results from Parkinson's disease patients who do not have voice symptoms and to compare these results with those from age- and sex-matched control subjects. Prospective. Tertiary reference hospital. The objective acoustic analysis results from 14 female Parkinson's disease patients with no voice symptoms were compared with those of 22 age- and sex-matched normal subjects. Statistical analysis revealed no differences in mean fundamental frequency and shimmer values. However, differences in jitter values, loudness, and the harmonics to noise ratio were statistically significant between the two groups (p < .05). With this study, it was shown that Parkinson's disease patients who do not have any voice symptoms have objectively different acoustic values than their age- and sex-matched controls. Clinicians must be aware of these initial findings on the voice changes of Parkinson's disease patients.

The voice of patients with laryngeal carcinoma after oncosurgery

The voice of patients indicated for surgical procedures in treating of dysphonia is already damaged before the operation. The problem, which exists at the level of glottis patients usually try to solve by compensative mechanisms. The quality of voice after the interventions in larynx depends on the type and width of resection, disturbance of physiological phonation mechanisms, and ability to establish optimal phonation automatism. The damage of laryngeal structure, especially its glottic part and vocal cords as its central part, no matter if they are just fibrous or they are partially or totally absent, leads into the development of substitutive phonation mechanisms. The most frequent substitutive mechanisms are: vestibular, ventricular, and chordoventricular phonation. There are some variations of these phonation mechanisms, which are conditioned not only by applied surgical technique, but as they are also individual characteristics, they can be the consequence of applied rehabilitation methods. The diagnosis of voice condition before and after the oncosurgical procedure is done by: laryngostroboscopy, subjective acoustic analysis of voice, and objective acoustic analysis of voice (sonography or computer analysis of acoustic signal). The most of laryngeal carcinomas appear in glottic region, so the function of phonation imposes itself as the objective parameter to measure the quality of life after the oncosurgery of larynx. That is the reason why according to the priority, it is just behind the principle of "oncologic radicalism". Phonation as the most complex laryngeal function seems to have secondary importance. All known operative techniques, especially partial resections, have the preservation of phonation as their goal.

Study of lubricant-induced changes in chronic snorers (SLICCS)

The efficacy of many of the noninvasive treatments for snoring has not been evaluated in controlled trials. This paper seeks to evaluate the efficacy of an oil-based spray in the treatment of snoring, in a double-blinded, placebo-controlled, crossover trial using objective acoustic analysis and subjective questionnaires. Participants were randomized to use both oil-based oral spray (treatment) and water-based oral spray (placebo) during a two-night in-home study period. Questionnaires were completed by participant and bed-partner in addition to audio-tape recordings which were analyzed for frequency, duration, and mean energy of snoring. Greatest snoring rate demonstrated 30% = benefit; 40% = no change; 30% = adverse effect (n = 20). Percent time snoring yielded: 30% benefit; 15% no change; 55% adverse effect (n = 20). Study data results for mean energy were (n = 12): benefit = 17%, no change = 33%, adverse effect = 50%. Bed-partner observations (n = 17) demonstrated 37% = benefit; 38% = no change; 25% = adverse effect. Objective and subjective evaluation of the performance of the oil-based Snoreless spray in comparison to placebo demonstrated a lack of efficacy in snoring reduction.

Multidimensional assessment of voice and speech after supracricoid laryngectomy with cricohyoidopexy

This study was designed: to evaluate the vocal function in the patients with supracricoid laryngectomy (SCL) compared with normal subjects; to determine the factors affecting voice (such as number of arytenoid(s) preserved and movement of larynx and tongue base); and to determine the correlations between videolaryngostroboscopy, acoustic and perceptual parameters. Ten patients who underwent SCL with cricohyoidopexy for primary laryngeal squamous cell carcinoma were included into the study. Vocal function was investigated by means or videolaryngostroboscopy. Voice quality was assessed by means of objective acoustic analysis and subjective perceptual ratings by trained raters. Aberrant, incompetent, and rough mucosal wave was observed in the anterior and superior surfaces of arytenoids(s), the inferior part of tongue base and the lateral walls of the hypopharynx. The acoustic parameters were found to be significantly different from those of normal subjects. The values of perceptual scores were approximately within 50 per cent of normal range. The number of arytenoids spared did not affect acoustic or perceptual measurements. A rough, breathy, unpleasant but intelligible and acceptable voice could be obtained after SCL with cricohyoidopexy.

Study of lubricant-induced changes in chronic snorers

Problem: The efficacy of many of the noninvasive treatments for snoring has not been evaluated in controlled trials. This study seeks to evaluate the efficacy of an oil-based spray in the treatment of snoring, in a double-blinded, placebo-controlled, cross-over trial using objective acoustic analysis and subjective questionnaires. Methods: Participants were randomized to use both oil-based oral spray (treatment) and water-based oral spray (placebo) during a 2-night in-home study period. Questionnaires were completed by the participant and his/her bed-partner; these were evaluated along with audiotape recordings, which were analyzed for frequency, duration, and mean energy of snoring. Results: Greatest snoring rate demonstrated 30% = benefit; 40% = no change; 30% = adverse effect (n = 20). percent time snoring yielded: 30% = benefit; 15% = no change; 55% = adverse effect (n = 20). Study data results for mean energy were (n = 12): 17% = benefit; 33% = no change; 50% = adverse effect. Bed-partner observations (n = 17) demonstrated 37% = benefit; 38% = no change, 25% = adverse effect. Conclusion: Objective and subjective evaluation of the performance of the oil-based Snoreless spray in comparison to placebo demonstrated a lack of efficacy in snoring reduction. Significance: Study findings indicate that oil-based oral sprays are not effective in the treatment of snoring. Support: None reported.

Popular snore aids: do they work?

Objective The study goal was to critically evaluate 3 popular noninvasive treatments for snoring: an oral spray lubricant applied before bedtime, a nasal strip designed to maintain nasal valve patency, and a head-positioning pillow. Study design Prospective, randomized blinded clinical trial of 3 popular noninvasive snore aids using objective acoustic snoring analysis and subjective patient and bed-partner questionnaires in 40 snoring patients. A digital recorder allowed snoring analysis with data collected in the home environment over 1 week. Results There is neither objective nor subjective benefit to the use of tested popular noninvasive snore aids. Palatal snoring, palatal loudness, average loudness of snoring, averaged palatal flutter frequency, and respiratory disturbance index did not significantly change when comparing the 3 snoring aids with no treatment. Subjective comments and complications are reviewed as well. Conclusion This is the first prospective comparison trial of popular noninvasive snoring aids. There is no significant objective or subjective snoring improvement in the anti-snoring aids studied compared with the use of no aid. Significance Outcome studies aid in verifying or refuting claims made by popular noninvasive snore aids.

Recognition of vocal expression of emotion and its acoustic attributes

The vocal expression of emotion was examined with both an auditory experiment and objective acoustic analyses. In the auditory experiment the stimuli were words or short sentences with six basic emotions expressed by two actors. Forty-five undergraduate and graduate students participated in the experiment. The results showed that the vocal expression of emotion was strongly identified, except in the case of fear, and that the six basic emotions could be plotted in a psychological space with two dimensions calculated from multidimensional scaling. The plot formed a roughly circular surface, with locations very similar to those of the facial expressions. One dimension was considered to represent the element of pleasantness-unpleasantness. The actors voices were then acoustically analyzed. The results suggested that the mean fundamental frequency (F0), the standard deviation (SD) of F0, and the SD of the energy are the important factors that define the characteristics of the vocal expression of emotions. To determine the most important parameter(s) and explain the two dimensions of the psychological space, canonical correlation analysis was conducted. The analysis indicated that F0 was correlated with the pleasantness-unpleasantness dimension.