valdís ingibjörg jónsdóttir akureyri, iceland

VALDÍS JÓNSDÓTTIR VANCOUVER, MAY 2005

Valdís Ingibjörg Jónsdóttir Akureyri, Iceland

BENEFITS OF TEACHING

VOICE AMPLIFICATION

AS RELATED TO SUBJECTIVE

LARYNGEAL SYMPTOMS IN TEACHERS,

AND TO THE LISTENING CONDITIONS

FOR STUDENTS


Background

Poor acoustics, high background noise, too great a distance between learners and

teachers are known risk factors for the teachers voices and students’ ability to

hear the teachers.


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)


Risk Factors For Children’s Hearing

Physiological, psychological or social:• Hearing problems• Underdeveloped hearing ability • Language disorders• Development disabilities• Learning disabilities• Bilingual

Environmental• Background noise, reverberation, distance


Amplification in Classrooms

Research have indicated:Teachers:• Evaluations by teachers indicate that amplification

reduces vocal strain and voice fatigue (Sarff, 1981; Gilman and Danzer, 1989; Rosenberg et al., 1994)

Students: • Sound field amplification improves student’s

speech recognition, academic achievement, learning behavior, ability to receive instruction and improves the classroom behavior of young children (Sarff, 1981; Gilman Danzer, 1989; Palmer, 1998; Allen and Patton, 1990)


Aims of the Study

• Investigate the effects of amplification on the vocal parameter of teacher’s voices in the classroom

• Collect data on students and teachers opinion on amplification

• Reveal other benefits and/or disadvantages of the usage of amplification in classrooms


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


Subjects

• 33 Icelandic teachers (26 females and 7 males; mean age 45 (27 – 64) years; teaching experience mean 16 (1 – 32) years: class hours mean 23 (6 – 38) lessons (basic school, junior college, university)

• 791 students (446 females and 345 males; age 6 - < 20).


Methods

• Teachers used amplification in class for at least a week. • Three questionnaires were used at the end of the research

period. Teachers • 27 multiple-choice questions to elicit background information,

stressfulness of the teaching, sick leaves because of voice failure, concern about learners ability to hear them.

• 12 multiple-choice questions to obtain opinions on effects of amplification on voice and attention of pupils. Free comments on disadvantages of using amplification.


Methods

Students• Age 10 years and older, n=644

11 multiple-choice questions to obtain their opinions on effects of amplification. Free comments on advantages and disadvantaged of using amplification.

• Age 6 – 9 years, n=127 (were individually asked 2 questions)

• Did you like it when the teacher used an amplification system? Why?


Results

Results from the Teachers’ questionnaire


Background information of the teachers (n=33)

Young children at home 33

Activities (acting, guiding, coaching,) 48

Asthma, allergies, hearing loss 36 Decongestants or dehydrating medicine 33 Influenza more than four times a year 15 Singing in choir 36 Voice training 27 Had been to ETN because of voice problems 24 Treatment from a speech and language therapist

15

Smoking 9

%


Self reported vocal symptoms of

33 teachers

% Dryness in throat 51 Sore throat 21 Lump in throat 30 Tickle in throat 45 Hoarseness without cold 30 Voice inadequate in noisy situations 48 Aching shoulders, back or extrinsic neck muscles 61


Miscellaneous data

%

Sick days because of voice failure 18 Concerned that students had difficulty in hearing them 76 Teaching stressful 39


Teachers comments on amplification

Yes %

No %

Advantages for the teacher 91

You produce your voice differently 97

Easier to speak 97

You talk more 12 82

Necessary to repeat yourself when using amplification

9 88

Necessary to repeat yourself when not using amplification

82 15


Teachers comments on amplification

Yes

%

No

%Less classroom chatter 64 27

Students pay more attention 93 3


Free Comments from Teachers

Free comments from teachers (n=33) on disadvantages using amplification

• One third reported they lacked technical skill in installing or using the equipment

• One fifth reported that the equipment was inconvenient (e.g. it was difficult to transport the equipment between classrooms or the microphones were inconvenient)

• One fifth reported that the disadvantages were none or very few

• One fourth did not reply


Results

Results from

Students’ Questionnaire


Advantages for Students

Listening easier

Easier to follow the lesson

Easier to hear the teacher

Easier to concentrate

Less class chatter

Lessons more interesting

Fewer repetitions

20 40 60 80 100

84

77

87

63

45

58

35


Student Comments on Amplification

90

86

71

93

76

66

53

80

100

91

84

98

0 10 20 30 40 50 60 70 80 90 100

Listening easier

Easier to follow the lesson

Easier to concentrate on the lessons

Easier to hear the teacher through the class chatter

%

University students (n=57)

Junior college students (n=263)

Basic school students (n=208)


Students Comments on Amplification


Comments from 6-9 yr old Children

• Over 95% commented that they liked the amplification, as they heard the teacher better

• Some of them commented as well that the teacher was not as angry


Free Comments From Students

Examples from students (n=528)

Advantages when teachers used amplification

• Hear better 30%

• Hear better and........................ 46%

• Better for teachers voice production 12%


Free Comments from Students

Examples from students (n=528) Disadvantages when teachers used amplification

• No disadvantages 22%

• Technical problems or lack of technical skill in the teachers 37%

• Did not answer 9%

• Gives headache or make ears ache 5%

• Teacher forgets to switch off when talking to an individual student 4%


Discussion

• Majority of teachers and students reacted positively to the use of amplification in teacher’s classroom speech.

However for consideration:

• Subjects are too few to draw any conclusions

• All teachers participated voluntarily in the research

• Same questionnaire was used for all students from the age of 10 to over 20 years

• Possibility that the authors’ positive expectations may have been reflected in the questions


Main Advantages

• Benefits reported by teachers and pupils in this study are much in line with results from other studies (Sarff, 1981; Berg et al., 1989; Gilman and Danzer, 1989; Allen and Patton, 1990; Rosenberg, et al., 1994; Palmer, 1998; Flexer, Millin and Brown, 1990; Lehman and Gratiot, 1983)

• For teachers: reduced voice fatigue, less need for repetition, improved student attention, improved behavior, fewer distractions, diminished discipline problems For students: easier to hear the teacher, improved attention, class noise diminished, teacher heard without the need for straining.


Main Disadvantages

Teachers and students agreed that the main disadvantage related to amplification stemmed from:

• Technical problems • The teacher’s lack of knowledge about the proper

use of the equipment. Teachers and students cited: • Too much amplification • Acoustic feedback • Problems experienced in setting up the equipment


Research Results Point To

• The amplification system needs to be simple in use

• Appropriate number and position of loudspeakers

• The microphones have to be comfortable for the teacher

• The classroom has to have good acoustics. Too high reverberation time will cause amplification to become uncomfortable

• Teachers has to be given proper training in how to use it

• A person in the school with adequate expertise available in the school district to install and maintain the equipment

• This is much in line what Flexer et al (1995) emphasized


Conclusions

Teachers and the pupils agreed that use of an amplification system in the classroom

is “voice-ergonomic” i.e. the teachers voice is protected; and at the same time the learners can hear the teacher’s voice

more clearly


For consideration

• Limitation of voice to carry. According to ISO 9921-1 since 1996 at the distance of 1 meter the maximum A -weighted sound level (dB (A)) is 90 dB.

• Inverse square law. Causing the sound level in the voice to decrease by distance

• Lombard effect. Causing the teacher to strain his/her voice by increasing SPL


Thank You For Listening

valdís ingibjörg jónsdóttir akureyri, iceland

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