The use of electroglottography in the treatment ofdeaf adolescents with puberphoniaSemyon Chernobelsky

From the Department of Phoniatrics & Voice Research Laboratory of Krasnoyarsk Opera-House & Academy ofMusic, Perensona St. 2, Krasnoyarsk 660049, Russia

Log Phon Vocol 2002; 27: 63–65

Electroglottography (EGG) was used as a visual feedback tool in the treatment of four male profoundly deaf adolescentsof 15 years of age with puberphonia. A laryngograph, oscilloscope, computer, and laryngostroboscope were used for thisresearch. The EGG was used during phonopedic exercises, which consisted of the patient producing voiced coughing inmodal register and extended these into prolonged vowels. The investigation showed that EGG facilitated the production ofvocal fold vibration in the modal register. It was concluded that EGG was highly effective in changing the production ofvocal register and could be recommended in the treatment of puberphonia in the deaf.

Key words: vocal mutation, visual feedback, vocal registers.

Semyon Chernobelsky, M D, Ph.D., Private address for correspondence: Dubrovinsky S t. 56-20, Krasnoyarsk 660049, Russia.Tel.:Fax : »007 3912 279390. E -mail: semyon@ktk .ru

ORIGINAL ARTICLE

INTRODUCTION

Hearing is the sense upon which human communica-tion most fundamentally depends. Despite medical,socio-economic and educational measures, deaf chil-dren are still being born. In developed countries it isestimated that one in every thousand children is borndeaf, whilst in less developed countries the � gure canbe as much as four times as high (9). Deafness canhave many causes. It is generally agreed that abouthalf of all cases of hearing impairment in children isof genetic origin. Some of the other most importantcauses include diseases contracted by the motherduring pregnancy such as rubella and cy-tomegalovirus; perinatal factors such as anoxia, trau-matic brain damage, hepatitis and rhesus incom-patibility; certain other infectious diseases such asmeningitis, measles, viral encephalitis, mumps,malaria and herpes virus type two; otitis media andototoxic agents.

The voice of those who are profoundly deaf ischaracterized by its nasal and monotonous quality, areduced range of both pitch and loudness (6) and ahigher overall pitch (4). These effects are due to theloss of hearing feedback, the individual being unableto monitor their own voice (8). Abnormal vocal foldvibration is a common problem for hearing impairedspeakers, and along with intonation patterning is amajor focus of attention in therapy (1).

Age related changes to the larynx, also known asvocal mutation, when the larynx substantially aug-ments in size, normally occur in male adolescentsbetween the ages of 13 and 15. Because of the lack ofadequate auditory monitoring some deaf adolescentsretain falsetto voices after vocal mutation. This isknown as puberphonia.

Visual feedback is a powerful tool which has beenused in many areas. These include children’s voicepitch development (5), singing instruction (7), thetherapy of stuttering (10) and speech therapy withdeaf (1). In our previous investigations we used elec-troglottography (EGG) also known as electrolaryn-gography in the treatment of patients suffering frompsychogenic aphonia (2). We also used this method inthe treatment of adolescents with normal hearingsuffering from puberphonia (3). This allowed us tosuppose that using EGG for the treatment of deafadolescents with puberphonia could also be success-ful. In order to con� rm this hypothesis the presentstudy was conducted.

MATERIAL AND METHOD

The subjects were four lip-reading profoundly deafmale adolescents of 15 years of age suffering frompuberphonia. All patients lost their hearing duringtheir � rst year of life and studied at a special school

© 2002 Taylor & Francis. ISSN 1401-5439 L og Phon Vocol 27

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for the deaf. None of them were suitable candidates fora cochlear implant. They had normal sexual puberty,but spoke using only the falsetto register with a veryhigh, ‘thin’ sounding voice, which had a mean funda-mental frequency of 436 Hz.

EGG works by passing an electric current throughthe larynx. When the vocal folds are together thecurrent passes easily through the tissues of the larynx,however, when the vocal folds are apart the currentpathways are greatly lengthened around the glottis.This leads to greater impedance, which is re� ected asmodulation of amplitude in the EGG output. Theoutput of the EGG unit is a single trace display calledan EGG waveform or Lx waveform, which providesa real-time visual display of vocal fold activity. EGG� ndings were obtained using a Forcin laryngograph-6094 in conjunction with an oscilloscope and ananalog-to-digital converter operating into a computer,IBM-compatible Celeron 366 MHz. Special softwarewas written at the Siberian Technological Universityfor both data acquisition and analysis. Laryngoscopyand laryngostroboscopy were also used.

RESULTS

Laryngoscopy of patients performed before the treat-ment revealed adequate to the age growth of the larynx.The vocal folds were slightly pink in colour. Themaximal obtainable signal of the EGG had a sinu-soidal waveform of very small amplitude (F ig. 1b).Laryngostroboscopical � ndings indicated vocal foldvibration of a very small amplitude.

The treatment of puberphonia consisted of thepatient being asked to produce voiced coughing in themodal register and extend these into acceptable pro-longed vowels. EGG monitoring took place during thisexercise and the patients were asked to observe theEGG waveforms on the oscilloscope screen. It wasexplained to them which waveform corresponded tophonation or coughing in the modal register (F ig. 1a),and which to the falsetto register (F ig. 1b). After voiced

coughing they were asked to produce phonemes andshort words in modal register.

Production of chest resonance appeared in thepatients very quickly. The treatment lasted 40–50minutes per day for eight to ten days, after which thepatient was able to use the modal register without thehelp of the therapist. EGG waveforms con� rmed vocalfold vibration to be in the modal register (F ig. 1a).Laryngoscopy revealed a slightly pink colour of thevocal folds. Laryngostroboscopical � ndings indicatedvocal fold vibration with normal amplitude and a meanfundamental frequency of 184 Hz. Further examina-tions were carried out after six and twelve months, andcon� rmed that the adolescents were continuing to usethe modal register, having a mean fundamental fre-quency of 184 Hz and 182 Hz, respectively.

DISCUSSION

Numerous voice disorders appear during vocal muta-tion. During puberty the fundamental frequency (F0)of the voice decreases. This is due to the increase inlength and mass of the muscles, and of the connectivetissues of the vocal folds. Female and male adultsaverage F0 of 256 Hz and 128 Hz, respectively. Infemales F0 decreases only 3–4 semitones, thus, if vocalmutation does not occur, it is not regarded as beingabnormal. An adult male who speaks in falsetto tendsto be regarded as socially somewhat abnormal. Themajority of healthy adolescents have normal vocalmutation, however, if this process is disturbed, puber-phonia can arise. As a rule, the treatment of puberpho-nia in patients with normal hearing is not complicated,however, the use of EGG as a visual feedback toolfacilitates the production of the modal register. In thecase of the deaf, because of the lack of auditoryfeedback, a non-auditory type of monitoring is re-quired. We thus tried to use EGG for this purpose.

The type and rate of vocal fold vibration providethe essential framework for normal speech (1). Thetype of vocal fold vibration determines the vocalregister. Most authors consider that the male voicehas two main registers: modal, also known as normalor chest, and falsetto. The modal register is character-ized by relaxed, thick vocal folds. The rapid closingphase of the vibratory cycle produced by theBernoulli effect is clearly different from the sloweropening phase. The lower edge of vocal folds starts toclose, while the upper edge is still opening and viceversa. Thus the EGG waveform in this case is steeperon the upward slope and has a large amplitude (F ig.1a). In falsetto the folds are maximally lengthened,tense and thin, opening and closing rates are morenearly equal. The edges do not have so strong anin� uence on the voice production as in the chest

Fig. 1. The EGG waveform types (glottal opening isdownward): a. during phonation or voiced coughing inthe modal register; b. during phonation or voicedcoughing in the falsetto register; c. during voicedcoughing in a patient with psychogenic aphonia.

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The use of EGG in the treatment of deaf 65

register. Here the EGG waveform looks like a simple,sinusoidal vibration of small amplitude (F ig. 1b).

The patient could produce voiced coughing both infalsetto and in chest registers. Depending on the registerdifferent types of EGG waveform appear (F ig. 1b, a).The EGG clearly shows the difference between phona-tion in falsetto and modal registers. EGG also showsthe contrast between voiced and voiceless speech.

The EGG output from a patient when makingvoiceless utterances has a straight line form, con� rmingthe absence of vocal fold vibration, however, duringvoiced coughing an EGG waveform appears (F ig. 1c).Using this feedback we were able to use EGG in thetreatment of patients suffering from psyhogenic apho-nia (2).

CONCLUSION

The chest voice is one of the main focuses in the therapyof puberphonia. The results of investigation show thatour method of therapy quickly facilitates the produc-tion of the modal register in the deaf. EGG, being noninvasive and inexpensive, is highly effective in changingthe production of vocal register and can be recom-mended in the treatment of puberphonia in deafpatients.

ACKNOWLEDGEMENT

The author is grateful to Mr. Toby Sims for revisionof the English text.

REFERENCES

1. Abberton E, Fourcin A. Electrolaryngography. In: CodeC, Ball M (editors). Experimental clinical phonetics.Investigatory techniques in speech pathology and thera-peutics. London & Canberra: Croom Helm, 1984. pp.62–78.

2. Chernobelsky SI. The use electroglottography for theevaluation of vocal fold vibration in the therapy ofpatients with psychogenic aphonia. Vestnik otorinolar-ingologii (Rus) 1990; 3: 57–8.

3. Chernobelsky SI. The treatment of puberphonia usingvisual feedback. Vestnik otorinolaringologii (Rus) 1996;4: 48–9.

4. Higgins MB, Carney AE, Schulte L. Physiological as-sessment of speech and voice production of adults withhearing loss. J of Speech and Hearing Research 1994; 37:510 –21.

5. Howard DM. SINGAD: a visual feedback system forchildren’s voice pith development. In: White P (editor).Child voice. Stockholm: KTH Voice Research Centre,2000. pp. 45–62.

6. Lane H, Wozniak Webster J. Speech deterioration inpostlingually deafened adults. J Acoust Soc Am 1991; 89(2): 859 –66.

7. Miller DG, Schutte HK, Doing J. Voce Vista. Visualfeedback for singing instruction. Proceedings of Interna-tional Symposium of Vocal Arts Medicine and VoiceCare, Salzburg, 2000.

8. Nickerson RS. Characteristics of the speech of deafpersons. Volta Rev 1975; 77: 342–62.

9. Prasansuk S. Prevention of hearing impairment anddeafness. Proceedings of the XXIII World Congress ofthe IALP, Cairo, 1995; 387.

10. Smolka E, Adamczyk B. Visual feedback for stutteringtherapy. Proceedings of the XXII World Congress of theIALP, Hannover, 1992.

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