Keyword :
functional voice hyperfunction , functional voice problems , voice problems , stemversterking , perseptuele stemeienskappe , Voice Handicap Index )VHI , voice conservation , onderwysers , akoestiese stemeienskappe , funksionele stemhiperfunksie professionele stemgeb , funksionele stemprobleme , stemkonservering , perceptual properties of voice , acoustic properties of voice , professional voice users , Teachers , stemprobleme , voice amplification , Voice Handicap Index )VHI(