VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Valdís Ingibjörg Jónsdóttir Akureyri, Iceland BENEFITS OF TEACHING VOICE AMPLIFICATION AS RELATED TO SUBJECTIVE LARYNGEAL SYMPTOMS AND PERCEIVEDVOICE QUALITY IN TEACHERS

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Background Teachers are one of the largest groups of professional voice users Of all occupations, those engaged in teaching are considered to be the most at-risk of incurring voice problems (Verdolini and Ramig, 2001; Vilkman, 2001). Voice problems are common among teachers worldwide.

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Risk Factors for Teachers’ Voices Physiological: Prolonged voice use (e.g. Lauri et al, 1997, Stemple et al 1995) Majority of teachers are women. Female voices may be more vulnerable to vocal loading as their vocal mechanism is smaller and of weaker structure (Vilkman, 2000, Fritzell, 1996). Psychological: Teachers find teaching stressful (e.g.Kyriacou and Sutcliffe, 1978; Sapir et al., 1993) Environmental: Background noise, too high reverberation, distance (e.g., Ko, 1979; Markides, 1986; Pekkarinen and Viljanen, 1990; Vilkman, 1996)

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Effects of Amplification on Voice Evaluations by teachers indicate that amplification reduces vocal strain and voice fatigue (Sarff, 1981; Gilman and Danzer, 1989; Rosenberg et al., 1994)

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Aims Shed light on whether the use of amplification in classrooms would: Diminish the teachers' experienced symptoms of vocal fatigue Cause a change in perceptual voice quality during a teacher's working day Whether these changes were different when amplification is used in classrooms

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Methods Eventually subjective changes in vocal symptoms with comparison of questionnaire results Perceptual quality changes in teacher’s voices during a working day –In ordinary teaching conditions –When using electric sound amplification while teaching

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Characteristics evaluated with VAS scale Overall voice quality Definition Vocal fatigueMono-pitched, tensed, breathy and hoarse voice (Colton and Casper, 1990). BreathinessAudible escape of air through the glottis due to insufficient glottal closure (Hammarberg, 1992). StrainednessVoice sounds strained as if the vocal folds are compressed during phonation (Hammarberg, 1992). AsthenityA high-pitched female-like weak voice (Isshiki, 1969).

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Characteristics evaluated with VAS scale Overall voice quality Definition CloudinessPossibly perceptual sign of laryngitis or vocal fatigue. Damped, not clear voice. Poor condition of voice. ClarityOpposite to cloudiness: a clear and audible voice. Good condition of the voice. Vocal fryLow-frequency periodic vibration (Hammarberg,1992). Voice breaksIntermittent frequency breaks (Hammarberg, 1992). Throat clearing PitchThe chief auditory correlation of fundamental frequency (Hammarberg, 1992).

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Subjects and Procedures Questionnaire study: 33 teachers (26 females and 7 males; mean age 45 (27 – 64) years; teaching experience mean 16 (1 – 32) years (basic school, junior college, university) Perceptual evaluating: 5 teachers (selected from 33 teachers) (3 females, 2 males; mean age 51 years) (basic school, sixth form college). First and last lesson of the week’s hardest working day recorded –Without amplification, One week later with amplification Working day: 5 -9 lessons, minutes Portable DAT and head-mounted microphone (Sennheiser MK 2; 7 cm from the mouth to the side)

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Amplification in Classroom Shure cordless amplification equipment A WL 184 lapel condenser microphone, ETGS transmitter & receiver Portable amplifier (Anchor AN100 or Trace Elliott 30 Watt) Amplification level chosen by teachers

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Data Analysis Two questionnaires Background information of the teachers Comments on amplification Perceptual evaluating Material 3 x 4 -minute samples from first and last lessons (from beginning, middle and end of lesson). Total 12 min per speaker during a day. Samples recorded in random order.

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Evaluation of Samples Evaluators: 2 professional speech trainers Place: In a damped studio Equipment: Genelec Biamp loudspeaker Evaluation scale: Average voice quality (poor / excellent); Vocal fatigue; roughness; breathiness; asthenia; strainedness; clarity; breaks; vocal fry; throat clearing (from 0 – 6) Pitch (suitable, too low/too high)

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Intra-inter reliability tested Intra- and interrater reliability (Spearman Correlation) was tested in the listening evaluation. One of the listeners evaluated the samples (N 60) twice. (The second rating used for calculating interrater reliability). NS = non-significant (p > 0.05)

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Results Results from Questionnaire and Perceptual Listening

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Background Information Factors which may influence the voice Half of the teachers Were taking part in activities (acting, guiding, coaching) One-third of the teachers Suffered from asthma, allergy or hearing loss Used decongestants or dehydrating medicine Had young children at home Were singing in choir

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Background Information One fourth of the teachers: Had received voice training Had been to ETN because of voice problems 15% of the teachers: Had influenza more than four times a year Treatment from a speech and language therapist 9% of the teachers were smokers

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Self reported vocal symptoms of 33 teachers Yes %No % Voice tired while reading loud5145 Voice tiredness while singing4839 Voice tiredness in conversation3658 Voice fail while teaching2761 Voice does not last in teaching situation 3654 Voice loss684

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Timing of Vocal Symptoms Experienced % While teaching63 In the winter51 In the evening48 In the spring21 In the morning18 In the autumn15 On weekends3 In the summer0

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 With and without amplification Teachers (n=33) comments on discomfort in voice mechanism while talking with and without amplification With ampl.Without ampl. Tongue and Lips6% Jaws6% Throat27%70% Tongue and throat15% Jaws and throat15% Do not know3% No response58%

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Teachers comments on amplification Yes % No % Less fatigue in the body6133 Less fatigue in the vocal mechanism889 Voice breaks while using amplification0100 Voice breaks while not using amplifcation 5545 Voice last longer826

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Perceptual Evalualtion of Teachers Voices (n=33) Voice quality with and without amplification in classroom When amplification was used voices were perceived significantly better in: –Quality (p=0.004) –Less strained (p=0.029) –Less rough (0.027) –Less asthenic (p=0.043) –With fewer voice breaks (p=0.030) No significant perceptual difference was found in pitch, breathiness, clarity, vocal fry and vocal fatigue

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Intra and Inter Observer Consistency Intra-observer consistency was: Satisfactory for all characteristics (r>050, p=0.001) except for vocal fry and vocal fatigue. For roughness intra-observer consistency was found low (r 0.42, p=0.012) Inter-observer consistency was: Satisfactory for pitch, vocal fry and throat clearing Little consistency was found for roughness, astenity, breathiness, clarity and vocal quality.

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Mean values of fundamental frequency (F0) and sound pressure level (SPL) in teachers’ classroom speech with and without amplification and the statistical significance of the difference (paired samples t –test). females (n=3)males (n=2) F0 (Hz)With Without Sig. p= 0.002p< SPL (dB)With Without Sig. p< 0.001p= 0.006

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Changes in Perceived Voice Quality Changes in perceived voice quality during a teacher’s working day. No significant difference was found in changes in perceived voice quality during a teacher’s working day except a small tendency for less asthenity while amplification was used (p=0.100)

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Discussion While using amplification teachers reported less fatigue in the vocal mechanism especially in the throat which may be partly related to decreased levels of F0 and SPL. Majority reported better voice production and less fatigue in the vocal mechanism and the body All subjects admitted to discomfort in the voice mechanism when teaching without amplification. While using amplification only 14 (42%) answered this question, which may suggest that no discomfort was felt.

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Listening evaluation by 2 voice trainers listening Voice quality was not found good in any of the samples Voices were perceived more relaxed when using amplification Voices were perceived less strained Less strainedness is in accordance with lower F0 and SPL Perceived strainedness increased during the working day somewhat more when amplification was used Roughness was found more often in voice samples taken in non-amplified conditions

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Listening evaluation by 2 voice trainers listening Voice was found to be less asthenic in amplified conditions No differences were found in perceived pitch although there were differences in F0 No significant difference was found in perceived vocal fatigue

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Conclusions The results suggest that vocal load has a significant effect on the general well being of the voice professional. Use of amplification in classrooms may diminish the vocal load and thereby contribute to better general well being of the teacher.

VALDÍS JÓNSDÓTTIRVANCOUVER, MAY 2005 Thank You For Listening