2. Materials and methods
2.1. Sample
In Brazil, the ‘‘Fonoaudio´logo’’ is the professional trained and qualified to act in the areas in Audiology and Communication
Disorders. In this paper we will denominate this professional as the Speech and Language Therapist (SLT).
The entry point for any patient in the Speech and Hearing Disorders Clinic of the University of Sa˜o Paulo Medical Faculty is
an interview performed by the Speech and Language Therapist, who collects information on maternal concerns about
hearing problems, language delay, and applies hearing and language tests if necessary. The sample of deaf children was
drawn from this group.
One hundred thirty-three participants (67 children with normal hearing; 3 with mild hearing loss, 3 with moderate
hearing loss, 40 with severe hearing loss and 20 with profound hearing loss) (categories based on Davis & Silverman, 1971)
aged 3–6 years old, were recruited. The deaf group were children whose parents sought help from the clinic at the University
of Sa˜o Paulo because of delay in language development and/or auditory problems; the second (control) group were from a
local government preschool. The six children with mild and moderate losses from the deaf group were subsequently
excluded, as they formed too small a group for research purposes. Therefore, the sample was comprised of 60 deaf children
(age mean = 55.5 months; standard deviation = 9.3; from 41 to 72 months) and 67 hearing children (age mean = 55.4 months;