The term “pediatric population” includes individuals from birth to eighteen years of age, and the Medical Subject Headings descriptors “pediatrics”, “child” and “adolescent” were used as basis for its creation and delimitation of the age group.

The Latin American and Caribbean Health Sciences (Lilacs), Medical Literature Analysis and Retrieval System Online (Medline) via PubMed and Scientific Electronic Library Online (SciELO), Web of Science and the Virtual Library of Saúde (BVS Portal) databases were searched, as well as the gray literature bases OpenGrey.eu, DissOnline, OpenDoar, OAIster and The New York Academy of Medicine. There were no language or publication date restrictions. The following search key was used: auditory evoked potential OR evoked potential, auditory OR potentials, auditory evoked OR auditory evoked response OR auditory evoked responses OR evoked response, auditory OR evoked responses, auditory OR auditory evoked potentials AND children OR child. The “Age: Child” search filter was used. The database search was carried out in March and April of 2020.

The review included only original case-control articles that performed BAEP-speech without competitive noise in the pediatric population with and without oral language disorders. Only case-control articles were included considering the need to compare the population with oral language disorders to those with typical development, being essential to perform the evaluation of similar age groups and using the same examination parameters. Literature reviews, studies without a control group, repeated articles in different databases, studies in non-human beings, as well as studies carried out in individuals with hearing loss, neurological syndromes and brainstem alterations were excluded.

The search was carried out by two independent reviewers, and, in the absence of agreement, the study was evaluated by a third researcher for final decision making.

The first phase of article selection included the reading of titles and abstracts of all identified studies. After excluding the ones that did not meet the objective of the current study and did not meet the eligibility criteria, duplicate articles were excluded. The remaining ones were then read in full, which led to the exclusion of studies that did not meet the review proposal.

The data extracted from the study results were: names of the authors, year of publication, country, sample size, age group of the studied group, type of oral language alteration, examination stimulation parameters, in addition to the mean slope values, amplitude, latencies, areas and main conclusions made available by the studies.

The Newcastle-Ottawa scale adapted for cross-sectional observational studies was used to assess study quality, which was independently evaluated by two researchers based on the following items: 1) Sample representativeness; 2) Sample size; 3) Management of non-responses; 4) Calculation of exposure (risk factor); 5) Comparability of subjects in different groups of results based on the design or analysis (control of confounding factors); 6) Evaluation of results; 7) Statistical test.

Studies that evaluated children with SLD showed comparisons with different groups. Filippini et al.16 performed the BAEP-speech before and after acoustically controlled auditory training, while two others14,15 performed a comparison with groups with typical development and central auditory processing disorder; the others had only members with SLD and a control group. These differences provided variability in the findings and discussions, and only the results concerning the comparison of children with SLD to those with typical development were described here.

The studies indicate an increase in the latency of the BAEP-speech waves in the groups that had language alterations;12,14,15 Filippini et al.16 shows a delay only in the E wave, while Basu et al.21 made no observation regarding this aspect in the evaluation with speech stimulus. The articles indicate that there is a reduction in the amplitudes of all waves,12,15,21 showing that the increase in the presentation rate implies in a decrease in the amplitude of the responses;21 one of the studies,16 however, indicates no alterations in this parameter in the group with SLD. No changes were found regarding the VA complex area. The study by Filippini et al.,16 did not observe changes in the latency values of the BAEP-speech waves without competitive noise in the SLD group before and after the acoustically controlled auditory training.

It can be observed there is no consensus in the literature regarding the results related to the latency and amplitude of the BAEP-speech waves; considering that one of the studies indicates a decrease in amplitude by increasing the presentation rate, the importance of using the same stimulation parameters for the exam is verified, thus reducing the variability of the findings.

There is an agreement in the literature regarding the reduction of the frequency encoding phase blocking, especially at the higher ones, making it difficult to perceive frequency changes.14,15,21 The response is also deteriorated by the increase in the stimulus presentation rate,21 indicating perception deficits in the rapid transition of temporal-spectrum elements in the speech of children with SLD.

As for spectral data, one of the studies21 indicates that the peaks appear unchanged only when there are lower rates of presentation, with a reduction in amplitude when this characteristic of the acoustic stimulus is increased, whereas two other articles14,15 did not observe differences in this regard between the groups with and without SLD. Studies agree that there is neural instability and reduced synchrony of speech responses in this population. Thus, it is possible to verify that children with SLD have difficulties in the subcortical and cortical encoding of speech sounds, impairing language development.

Of the studies that investigated individuals with ASD, only three9,11,18 presented numerical analyses of the results of the BAEP-speech. Ramezani et al.11 pointed out that there are higher latencies in all analyzed waves, but there are no differences in amplitude between the study and control groups, while Russo et al.18 identified only delays in components V, A, D and F and reduction in the F wave amplitude. Regarding the VA complex, the first study observed an increase in latency, with reduced duration and slope and, in contrast, the second study identified a prolonged duration of this component. The small number of studies that showed analyses of the characteristics of the BAEP-speech waves does not favor the possibility of consensus regarding the pathology findings with the examination performance.

One of the studies9 performed an assessment with BAEP-speech in two moments (T1 and T2) to observe the development of speech responses in the population with ASD. The children in the study group had lower V-wave latency and higher amplitudes of waves A and C in T2 compared to T1. When compared to individuals with typical development, the population with ASD had prolonged wave V and A latencies in T1, in addition to reduced wave E amplitude and F wave peak latency in T2, indicating development of auditory processing at the immature subcortical level in preschoolers with ASD.

The study carried out by Russo et al.,22 in contrast to the others, observed the pitch encoding in children with ASD, and identified a deficient encoding for speech pitch and less accurate tone tracking, highlighting a greater error in the speech frequency differentiation in individuals with ASD. Otto-Meyer et al.20 observed the stability of the responses in this population, evidencing the variability in response stability even in high-performance autists. The authors agree that in the same study group there are participants who have difficulty in the auditory processing of complex sounds, whereas others have similar responses to the group of children with typical development.

Two studies11,18 indicated that there is less representation of the speech start being presented, with a prolonged initial duration of the response. Other studies18,22 indicate the presence of phase block reduction, being presented with less accuracy. All the studies carried out on this topic agree there is a neural stability deficit, pointing out20,22 the possibility that these individuals have receptive and temporal prosodic speech deficits. Such aspects may be related to the difficulty in the social use of communication, considering that the perception of prosodic speech elements and the ability to use them in language expression is an important aspect for communicational effectiveness.

The two articles that investigated auditory processing for speech sounds in the population with Phonological Disorders (PD) differed on the assessment findings. Regarding latency, Ferreira et al.10 identified an increase in the values of all waves, however with significance only for the V, A, C, F and O waves, while Gonçalves et al.17 showed a delay only in the V and A components. Both indicate greater loss of acoustic cues in the transient portion of the stimulus. Only the last study mentioned analyzed wave amplitudes; however, there was no difference in the values between the study and control groups.

Regarding the characteristics of the VA complex, one of the studies17 indicated that there were no differences between the groups; in contrast, the second study10 identified a reduction in the wave slope and an increase in the area values, since they are inversely proportional measures, which may be indicative of an implicit reduction in neural activity during the appearance of the analyzed potential.

Both studies indicate that there are deficits in the perception of the temporal properties of speech sounds, which are related to changes in the synchronicity of neural generators that can impair the cortical processing of acoustic information. One of the studies10 indicates that the basis of the PD lies in the speech sound processing by the auditory system; thus, individuals with this alteration have neural encoding impairment of complex sounds. Studies agree that these difficulties can compromise language development skills and interfere with the individual’s social communication.

The application of BAEP-speech in the population with persistent developmental stuttering was identified only in the study of Mozaffarilegha et al.,19 which used graphic visibility and fractality to observe the complexity of the responses to the exam in individuals with oral language pathology and with typical development.

The study group showed greater complexity in the graphic index, compared to the group without alterations. They observed that the visibility of the BAEP-speech graph shows an association between topology and fractality with the long-term memory of the auditory system in the brainstem in children with persistent developmental stuttering.

The literature search showed only one article that studied the application of the BAEP-speech in children with ADHD. Jafari et al.13 points out the difficulty in observing the presence of C and O waves in the study and control groups, whereas the other waves are easily verified.

The study indicates there are higher latencies of waves A, D, E, F and O, as well as an increase in the duration of the VA complex in children with ADHD. It also observed a prolongation in the beginning and displacement phases of the stimuli, corresponding to waves A and O, thus identifying that there is less synchronization of the neural responses at the beginning and at the end of the speech acoustic event in the children of the study group. They also showed delays in waves D, E and F, indicating greater difficulty in understanding the sustained elements of speech. As for the VA complex, the study indicated, in addition to the prolongation of duration, smaller amplitude and slope of the component, showing a reduction in the neural synchrony in children with ADHD.

A lower signal-to-noise ratio was also found, dividing the average pre-response amplitude by the measurement after stimulation, and the high physiological noise may have influenced the processing of the stimuli and the obtained results. Finally, they suggest there may be an interference of the afferent (bottom-up) and efferent (top-down) neural pathways in the processing of speech and non-speech stimuli in the population with ADHD.