The voice as a working tool for teachers, may be affected by prolonged use, abuse or misuse behaviors that trigger work-related functional limitations. One of the most common symptoms of those who use their voice massively occupational purposes is laryngeal fatigue (FL), or vocal fatigue from muscular weakness. This longitudinal quasi-experimental pre-posttest study evaluated the effect that the use of the voice, analyzing sociodemographic, health and work, lifestyle and occupational risk factors, but mainly the effect produced by the prolonged use of the voice on noise after a day of work, 99 teachers of an institution of higher education in Colombia, compared to workers with less vocal use physical variables. Vocal symptoms questionnaire was applied to control the bias is taken pre and post conference recordings per worker Speech Analizer® software and subjective changes were reported after a day of work each worker. They were found changes in physical variables - acoustic effect of prolonged use of the voice after a day of work in the two groups of participants, in which case the effect was more significant in teachers in administrative - not teachers. The risk of voice disorders was directly associated with exposure to occupational risk factors and those associated with health conditions and lifestyle of individuals, the consequences were greater for the group of teachers; as being the voice its main tool, the use was higher and also likely to trigger symptoms vowel derived from laryngeal fatigue. The average fo variable for sustained phonation of the vowel / a /, which represents a neutral tone or sound in the usual tone, showed significant differences between groups (p = 0.048). In this case, the group of teachers reported an increase in the post-fo compared with no significant change to the administrative group after prolonged use of voice. Consequently, there were differences in the recorded value for the maximum fo (p = 0.025), low fo (p = 0.011) and the range of FO (p = 0.012) in the sustained emission of the vowel / a /. In the case of group administration, significant differences were communicated by decreasing the Buddhas, range and maximum and minimum frequency in the three vowels (/ a /, / i /, / o /) in contrast to what happened to the group of teachers. In the voice intensity they were also found significant differences between groups (p = 0.001) with a decrease of volume in the post, both average and minimum, maximum and range of intensity, in sustained phonation vowel / a / for the group of teachers; No statistical significance was found in the administrative group for these variables. It was demonstrated by objective measurements and verifiable results, the phenomenon of laryngeal fatigue, associated with the effects that occur after continuous voice demand, the impact discriminate between debit and gender variables.
