CHARACTERISTICS OF PHONETOGRAPHY ON SUBJECTS WITH DENTOFACIAL BALANCE IN POST VOCAL CHANGE

(1) Speech Language Pathologist; Master of Speech Language Pathology by the Dentistry School in Bauru, University of São Paulo – FOB/USP, Bauru, SP, Brazil. (2) Speech Language Pathologist Master of Speech Language Pathology by the Dentistry School in Bauru, University of São Paulo – FOB/USP, Bauru, SP, Brazil. (3) Speech Language Pathologist, Professor from the Department of Speech Language Pathology from the Dentistry College in Bauru/USP – FOB/USP, Bauru, SP, Brazil; PhD in Rehabilitation Sciences at the Hospital for Rehabilitation of Craniofacial Anomalies/USP. (4) Speech Language Pathologist, Professor from Department of Speech Language Pathology from the Dentistry College in Bauru/USP – FOB/USP, Bauru, SP, Brazil; Ph.D. in Pathophysiology in Medicine by Universidade Estadual Paulista.

Conflict of interest: non-existent performance. It was described by Damsté 1 and, in 1983; the Union of European Speech Language Pathologists proposed that this to be done as part of the evaluation of the voice of individuals with normal voices 2 . This exam may be performed manually or computerized 3 , and provides information on the profile of vocal range, through the definition of an area between the intensities obtained from the minimum and maximum frequencies of the vocal range 4-6 .
The literature has documented the use of phonetography to distinguish normal vocal voices 5,7,8 , documenting changes in voice due to fatigue, and to evaluate the change in vocal quality after voice therapy 4 , or vocal training for singing 6,9 . Specifically regarding the standardization of benchmarks, there are studies for the Thai population 10 , German 11 and Finnish 12 . In Brazil, a study that found that phonetography was effective in showing the characteristics of the voice in females elderly 13 , while another determined vocal characteristics during male vocal development 14 .
To examine the phonetography was used VRP Program (Voice Range Profile) from Kay Elemetrics' Multi Speech, with an unidirectional headset microphone, RM -MZ3R brand, positioned at a distance of 3cm from the lip commissure of the participant. The recordings were performed in an acoustically treated room. For the measurements of phonetography requested to issue the prolonged vowel "a" in modal register, for at least 5 seconds at intensities stronger and weaker as possible. The exam started in C 3 (dó 3 , 131 Hz) with continuous ascending and descending scale.
The analyzed measures were: • minimum and maximum fundamental frequency of the voice (F MÍN e F MÁX ), expressed in semitones (st) and Hertz (Hz), which correspond to higher notes and more serious musical scale produced in strong and weak intensities; • vocal extention (VE), expressed in semitones and Hertz, which is the extension of frequency, comprising the total number of musical notes played and analyzed by the difference between the maximum and minimum frequency; • minimum intensity and maximum intensity (I MÍN e I MÁX ), obtained from the lowest point of the lower curve and the highest point of the upper curve of phonetogram; • maximum dynamic extension (MDE) expressed in decibels, the largest difference in intensity between the upper and lower phonetogram curves in the same frequency; • phonetogram area, resulting area of the connection between all points of the lower and upper curve in relation to vocal range, expressed in dB.st and cm 2 . It was obtained from the data of VRP through a program that performs the conversion from dB.st to cm 2 , using the conversion factor of 0.045 cm 2 , in which 10 dB corresponds to 15mm and 12 st corresponds to 36mm 2 .
The measures from all frequencies given in the abscissa of the phonetogram obtained by VRP in the phonetography ( Figure 1) were converted from Hertz to semitone in order to allow the calculation of the phonetogram area, for being the semitone a linear measure which presents regular intervals in musical scale in 12 semitones, which does not occur with Hertz, which is an exponential measure. Moreover, the values of the vocal range in the literature have been used in semitones 5,8,13,23,24 , enabling later comparisons.
Studies also indicate to be an association between the dimensions of the vocal tract and the characteristics of voice quality and formants 15.16 ; between voice disorders and oral muscular disorders 17,18 , being described, too, the relationship between the severity of temporomandibular dysfunction and vocal quality 19 .
Despite the literature demonstrate the relationships between the characteristics of the stomatognathic system and speech function, no studies were found to examine the vocal parameters considering facial type and dento-occlusal balance condition. Being phonetography an important instrument for achieving vocal assessment, the objective of this study is to characterize the profile of the vocal range of male subjects with dentofacial balance after voice change, through phonetography.

METHOD
The study included 15 male subjects, after voice change, with ages from 14 to 35 years old (average = 18.86). Criteria considered for inclusion were: presenting medium facial type with medium and lower equilibrium; appropriate length of upper and lower lips, Standard I20facial profile, which was considered in relation to the nasolabial angle balance, facial convexity angle, ratio between average anterior facial height and lower anterior facial height, as well as the proportion of the lower face, the relationship of the first permanent molar in class I21; overbite and horizontal measuring between 1 and 4 mm 22 , not presenting vocal alterations, having completed vocal changes 14 , not having syndromic or neurological impairments related to speech or expressive or receptive language, being a native speaker of Brazilian Portuguese, not having undergone laryngeal surgeries, not having prior vocal training, not having hearing complaints, not being alcoholic, not being nor having ever been a smoker, presenting good general health and no symptoms of laryngeal or respiratory alterations on the exam day. For this, all subjects answered a specific form of auto-responder investigating the aspects mentioned above, but also underwent anthropometric measurements of the face, dental--occlusal evaluation, perceptual evaluation of voice as well as assessment of expressive and receptive language.
about the procedures and were asked to sign the "Term of Free and Informed Consent" for all participants.

RESULTS
From the examination of phonetography, it was found the measures of minimum fundamental frequency, maximum fundamental frequency, range from F MIN =89Hz±3Hz and F MAX =665Hz±197Hz, corresponding to ±14st and 63st±5st, and the number of semitones from the vocal range (VE=34st±6st). We also analyzed the values of the usual fundamental frequency (F 0 ) of the sustained vowel "a" from the 15 participants who underwent phonetography, where the average value was F 0 =111,26Hz±15,24Hz. Such information is presented in Table 1.
For the analysis of the fundamental usual frequency, the voices of individuals were recorded in a computer through the Sound Forge 7.0 program. The recorded speech sample was the sustained vowel "a" in normal tone and intensity, analyzed in the program Multi Dimensional Voice Program (MDVP) by Kay Elemetrics.
The average values of the fundamental frequency, minimum and maximum frequencies, vocal range, minimum and maximum intensities, maximum dynamic range and the phonetogram area were obtained by the results that are provided by the VRP program, and the average of the fundamental usual frequency by the MDVP program.
This study complied every ethical standard advocated for research involving human beings, having received approval from the Ethics Committee in Research of the institution where it was conducted, case number 88/2006. The subjects were informed  Table 2.
We obtained the phonetography values related to minimum intensity, maximum intensity, represented by I MIN =66dB±3dB and I MAX =114dB±5dB, respectively, and MDE, corresponding to 42±4dB,

average ( X ) and standard deviation (SD) corresponding to the minimum and maximum fundamental frequency, expressed in Hertz (Hz) and semitone (st), habitual fundamental frequency expressed in Hz, and vocal range in semitone (st), from the evaluated participants.
(F MIN= 88,89±13,73Hz and F MAX= 760,96±167,17Hz) 14 , another which studied voice with training for singing and untrained (F MIN =86,1Hz±14,01Hz and F MAX =785,4Hz±188,38Hz) 9 , and similar to those of patients with reflux laryngitis and normal subjects (F MIN =83±10,9Hz and F MAX =696,6±106,2Hz) 8 . Although these studies do not address the Brazilian population, with the exception of a study 14 and do not take into account the facial typology and dento--occlusal harmony, the values were similar.
The average of the vocal extension obtained in this study (VE=34st±6st) is consistent with that described for the non-professional men singers without changing voice (VE=37st) 11 ; voices of trained and untrained individuals (VE=34,1st) 6 , and two other studies already mentioned (VE=37±4,70st) 14 , (VE=36,6±2,9st) 8 . However, the results of the present study was higher than the average obtained by another work (VE=19,7±2,54st) 23 which may be related to the methodology applied, as in this study, the patients underwent computerized automated phonetographs without the presence of the evaluator and the video instructions.
In regards to the fundamental frequency, when comparing the average value (F 0 =111,26Hz±15, 24) with other studies that also investigated the extent

DISCUSSION
The phonetography is a measure capable of recording all laryngeal possibilities regarding the frequency and vocal intensity, as it covers sounds more acute and severe that the human larynx is able to produce and the highest and lowest intensities generated during the emission of a vowel 2,13,24,25 . Despite the importance of the exam, no studies were found related to the reference values of the voice range profile in Brazilian Portuguese speakers without voice disorders in the young-adult age group, with dentofacial balanced conditions. Thus, in the present study it was performed an acoustic evaluation of the voice in Brazilian Portuguese male speakers, after voice change, no alteration or vocal training, who had the Standard I kind of face and dento-occlusal harmony.
The frequency measures were analyzed in the extremes of the vocal range by computed phonetography. In regards to the averages of the minimum frequency (F MiN =89Hz±3Hz) and maximum frequency (F MAX =665Hz±179Hz) of the phonetogram, the results obtained in this study are similar to those found in studies with men without voice disorders in the post-voice change

Table 2 -Individual values , average ( X ) and standard deviation (SD) of the maximum and minimum intensities, and maximum dynamic extension range (MDE) expressed in decibels (dB), and the total area of the phonetogram expressed in dB.st and cm 2
between all points of the lower and upper curve of the graph, the average obtained in this study was greater than those probably due to the results related to the frequency 6 and intensity 23 also being higher, reflecting the graph area.
Although the literature did not appear to consider the condition of dentofacial individuals, the results were similar to the VE 6,8,11,14 and MDE 6,8,14,23 , suggesting that the anatomical aspects of the stomatognathic system does not influence such vocal acoustic parameters. Moreover, according to the findings of this study, the fundamental frequency, minimum and maximum intensity, and the phonetogram area can be influenced by the position of articulators, which have intrinsic relationship with the laryngeal speech function.
In the literature, no studies were found that considered the acoustic vocal anatomical conditions of the face and occlusion in men. Although the studies presented did not consider the condition of dentofacial individuals, some results were similar.
In Brazil, there are no studies of standardized reference values for men, despite the phonetography be used as an instrument for voice evaluation. It is suggested that the phonetography be used in other studies to continue the investigation of the possible relationship of vocal parameters in various facial typologies and dento-occlusal relationships.

CONCLUSION
This research allowed us to study the profile of the vocal range of individuals with dentofacial balance after voice change through phonetography. The averages from the usual, minimum and maximum frequency were F o =111,26Hz (29st), F MIN =89Hz (63st) and F MAX 665Hz, respectively, the average vocal range of 34st and average values of minimum and maximum intensities and maximum dynamic range of I MÍN =66dB, I MÁX =114dB and EDM=42dB, and an average area of phonetogram of 936.4 dB.st (42.1 cm 2 ).

ACKNOWLEDGEMENTS
We would like to thank the FAPESP -Fundação de Amparo à Pesquisa do Estado de São Paulo (Foundation of Research Support from the State of São Paulo), for the financial support through the scientific initiation scholarship. of F 0 in Brazilian Portuguese speaking men and without vocal alterations, it was observed that the result was similar to a study (F 0= 109,05) 14 . On the other hand, other studies have found fundamental frequency higher than those obtained in the present study, in normal voices (F 0 =120Hz) 26 ; standardizing the fundamental frequency in a developed program by the Engineering School of São Carlos (F 0 =127,61Hz) 27 , and to analyze the operation and the type of voice in different microphone positions (F 0 =130,19Hz) 28 . The difference suggests that the dentofacial condition can influence the position of the larynx, and also in the fundamental frequency. In a study conducted after orthognathic surgery it was reported that the change in facial profile of the patient led to changes in the fundamental frequency of the voice and the positioning of the hyoid bone after surgery 29 .
Considering the average values obtained for the minimum and maximum intensity (I MIN =66dB±3dB and I MAX =114dB±5dB), the values were similar to those of two other studies (I MIN =66±3,48dB and I MAX =118±2,62dB) 14 and (I MIN =67,6±2,41dB and I MAX =115,5±3,84dB) 23 , but were higher than others (I MiN =46,6dB±5,74dB and I MaX =100,3dB±5,57dB) 9 , (I MiN =46,2±0,4dB and I MAX =95,4±3,7dB) 8 and (I MiN =50,9dB and I MAX =97,3dB) 6 indicating that the presence of dentofacial equilibrium can facilitate not only the articulation of the headphones, but also the phonation process, allowing to reach higher maximum and minimum intensities, through increased air pressure during phonation, as well as better laryngeal control of the passage of air current 30,31 . However, such hypotheses should be tested in future studies, by comparing groups of individuals with dentofacial balanced condition to those with dentofacial deformities.