The Acoustic Analysis Of Mutational Voice

The voice is changable, it has its own characteristic feature and variation.The variation of the voice is especially notable afer entering adolescent. Dueto the significant changes of sex hormones level, the volume of larynxincrease rapidally in a short time and result the notable change of the voice.The duration of this time is called mutation period, that is the voicetransforming from childish voice to adult voice. The studies on the voiceacoustic parameters of the mutation period is less up to now. It is necessary tostudy the voice acoustic parameters of the mutation period. It can provideeffective reference standard for diagnosis of the vocal disease and appraisal ofthe treatment.Objectives:1. To get the acoustic parameters of mutation period throughcomputerized acoustic analysis, and to study the regularity of mutationalacoustic parameters, and to analysis the voice characteristics and differencesbetween sexs and ages. Try to establish a mult-parametric objective evaluationprotocal of mutation period.2. To adopt suitable acoustic parameter values bysubjective evaluation and mult-parametric analysis of computer, and to givesome help for clinical workers and offer some values for evaluate the normaland innormal voice.Methods:1. subjects: The all subjects were developing normally, withno defect and dysfunction of the phonating system, without addiction totobacco and alcohol, and without acute upper respiratory tract infection. Thecontrol group were confirmed by laryngostroboscope with no laryngealdisease and vocal lesion. The voice samples were collected from1028students of mutation period aged between10-20. The mutation period groupseperated into3groups:premutation period, mutation period and postmutationperiod.2. the method of detection:2.1perceptual appraisal: All of the subjectsrepeated the same sentence in10to15seconds and the voice samples were all recorded in an isolation booth. The ambient noise of the isolation booth waslesser than45DB. The panel of judges consisted of three experienced andtrained specialists in voice. Each voice sample received perceptual appraisaland all the samples were seperated into hoarse group and non-hoarse group.The hoarse group contained66cases of men and7o cases of women, and thenon-hoarse group contained168cases of men and163cases of women.2.2detection of the voice acoustic parameters: The voice acoustic parameterswere measured mainly on a sustained vowel/ɑ:/were recorded on a softwarenamed MDVP for there times. The voice samples were all recorded in anisolation booth. The ambient noise of the isolation booth was lesser than45DB.The results were the average values of the three times. The objectiveparameters, including fundamental frequency(F0), Highest FundamentalFrequency(Fhi), Lowest Fundamental Frequency(Flo), Jita, jitter, shimmer,Amplitude Perturbation Quotient(APQ) and Noise to Harmonic Ratio(NHR).Results: Table1showed: there were1252pople were collected,588male numbers and664female numbers, that can be divided into thepremutation group, the mutation group, the postmutation and the normal adultpeople group. the mutation group which also can be divided into two groupsaccording to hoarseness or not. Table2showed: the acoustic parameters ofpremutation between different sexs and ages. During the premutation periodthere have no obvious difference between the same sex (P>0.05). Fo,Fhiwere significantly different between the same age of male and female(P＜0.05), the others were no significant；At the age of ten, in addition to the Flothe value had no significant difference (P>0.05), the other parameter valueshad obvious difference(P<0.05); At the age of eleven, Jita,Jitt had obviousdifference(P<0.05), Flo,Shim,APQ,NHR had no significant difference(P>0.05). At the age of twelve, in addition to the NHR, the value had nosignificant difference(P>0.05), the other parameter values had obviousdifference(P<0.05). Table3showed that the acoustic parameters of differentages in male hoarseness group. Table4showed that the acoustic parameters ofdifferent ages in male nonhoarseness group. Table5showed that the acoustic parameters of different ages in female hoarseness group. Table6showed thatthe acoustic parameters of different ages in female nonhoarseness group. Table7showed: Fo,Flo (p＜0.01),Fhi(P<0.05) the values had obvious difference;Jita, Jitt,Shim,APQ,NHR had no significant difference(P>0.05) betweenthe male and the female of the same age in hoarseness group. Fo,Fhi, Flo,Jita, Jitt, the values had obvious difference(p＜0.01); Shim,APQ,NHRhad no significant difference(P>0.05) between the male and the female of thesame age in nonhoarseness group. In male, addition to Flo the value had nosignificant difference the others had obvious difference between thehoarseness group and the nonhoarseness group; In female, addition to Fhi thevalue had no significant difference the others had obvious difference betweenthe hoarseness group and the nonhoarseness group. Table8showed that theacoustic parameters in the same age of the postmutation had obviousdifference between the different sexs. Table9showed: In male, Fo, Fhi,Shim, APQ and NHR had obvious difference (p＜0.01), Flo,Jita,Jitt had nosignificant difference between the premutation group and the normal peopleguoup; the all acoustic parameters had obvious difference between themutation group and the normal people guoup; in addition to Shim, APQ,NHR the value had obvious difference (p＜0.01), the others had no significantdifference between the postmutation group and the normal people guoup;Table10showed: In female, in addition to Jita, Jitt the value had nosignificant difference, the others had obvious difference between thepremutation group and the normal people guoup; in addition to Jita the valuehad no significant difference, the others had obvious difference between themutation group and the normal people guoup; there were little differencebetween the postmutation group and the normal people guoup, Shim, APQ,NHR had obvious difference(p＜0.01), the others had no significantdifference.Conclusions:1. The study confirms that from the premutation period F0has a significant difference between the male and the female in objcetiveparameter of voice through computer and it is necessary to analyze results separately according to the sex.2. Try to establish objective acousticparameters ranges of different sexs and ages in mutation period, which havedifferent voice characteristics, the reference values have important meaningfor evaluate the normal and innormal voice.