**3.2 Electrophysiological evaluation**

Auditory evoked potentials are an extremely useful instrument for the study of auditory perception and its disorders, especially when a range of stimuli are used [27].


*n = number, \* = number of ears, B = both, R = right, L = left;* ∑ *= mean, SD = standard deviation, DD = dichotic digits, SSI = synthetic sentence identification, FPT = frequency pattern test, GIN = gaps-in-noise.*

**71**

**Figure 3.**

*Click ABR. Personal collection.*

*Otitis Media, Behavioral and Electrophysiological Tests, and Auditory Rehabilitation*

In the literature, there are contradictory results in Click ABR responses in individuals with a history of OM. Chambers et al. [28] and Folsom et al. [29] identified an increase in the latency of waves III and V in a group of children with a history of OM, whereas Shaffer [30] did not find a statistically significant difference in Click ABR responses in individuals with and without a history of OM. The majority of studies relating Click ABR results with OM history have investigated latency values; however, Maruthy and Mannarukrishnaiah [31] found a reduction in the amplitude of waves I and III. Sanfins et al. [32] observed statistically significant differences in the absolute latencies of waves I and V as well as in the amplitude of waves III and V from children with a history of bilateral OME compared to their healthy peers. Colella-Santos et al. [11] reported a significant increase in the absolute latency of wave III associated with a decrease in amplitude in children with bilateral OME. Finally, Sanfins [33] reported alterations in the values of waves III and V for both groups of children with a history of OME, seeing both bilateral and unilateral

In animals, the effect of conductive hearing loss on CANS was studied by unilaterally removing the malleus and applying a fluid to simulate OM [34], finding a decrease in neuronal activity due to changes in various structures (wave III), upper olivary complex (wave IV), and lateral lemniscus (wave V). At the same time, based on the results of Maruthy and Mannarukrishnaiah [31], it has been suggested that the auditory nerve and cochlear nuclei are more susceptible to modifications after

Sanfins et al. [32] suggest that different modifications may occur in CANS structures depending on the unilaterality or bilaterality of the infection. In episodes of bilateral OME, the latency values indicated that the auditory nerve (wave I, wave III) and the lateral lemniscus (wave V) were affected, whereas in unilateral OME, the cochlear nuclei (wave III) was affected. However, when the amplitudes were analyzed, the structures involved were the cochlear nuclei (wave III) and the lateral lemniscus (wave V), both for children with unilateral and bilateral involvement. It should be noted that when evaluating click ABR, the amplitude values show greater variability than the latencies. It is important to emphasize that a unilateral OM may not provide a better performance in the processing of auditory information than bilateral OM. The use of only one ear can lead to damage to the functionality of

*DOI: http://dx.doi.org/10.5772/intechopen.88800*

*3.2.1 Click ABR*

alterations **Figure 3**.

OM infection.

#### **Table 1.**

*Behavioral evaluation values of central auditory processing between control and experimental groups.*

*Otitis Media, Behavioral and Electrophysiological Tests, and Auditory Rehabilitation DOI: http://dx.doi.org/10.5772/intechopen.88800*

### *3.2.1 Click ABR*

*The Human Auditory System - Basic Features and Updates on Audiological Diagnosis and Therapy*

by generating a fluctuating auditory threshold and causing temporary auditory deprivation, hampers the maturation of auditory abilities (such as binaural integration, resolution, temporal ordering, and discrimination) which are fundamental for understanding speech. During this period of auditory deprivation due to episodic OM, the CANS received inconsistent and incomplete auditory information. That is, the period between clinical assessment and the decision to perform surgery may

Recent research has demonstrated associations similar to those found in the present study. Borges et al. [11] studied the effect of OM in 69 children of different socioeconomic levels who underwent surgical intervention (insertion of ventilation tubes) and observed worse performance in both the DD and GIN tests. The authors concluded that a history of OM can lead to changes in central auditory functioning,

Khavarghazalani et al. [24] evaluated 12 children with a history of OM who had undergone surgical intervention for insertion of ventilation tubes and found worse

Gravel and Wallace [25] also found a significant increase in signal-to-noise ratio in a prospective study of children with a history of OM. There was worse performance on the SSI test (responsible for the figure-ground ability) in the OM group. Tomlin and Rance [26] recommend that children with a history of OM undergo an evaluation of spatial processing upon entering school. They studied 35 children with a history of chronic OM and found a statistically worse performance compared to the control group in the listening in spatialized noise-sentences test (LISN-S). They concluded that these children have altered spatial processing, difficulty in focusing attention on the relevant stimulus, and difficulty in simultaneously suppressing competing stimuli coming from other directions. It is hypothesized that fluctuating access to binaural cues, caused by OM, may negatively affect the

Auditory evoked potentials are an extremely useful instrument for the study of auditory perception and its disorders, especially when a range of stimuli are

DD R 40 98.93 1.86 50 95.40 5.16 <0.001

Humming B 80\* 73.50 21.2 100\* 42.7 22.2 <0.001 Verbalizing B 80\* 73.50 21.2 100\* 42.7 22.2 <0.001 SSI B 80\* 67.5 13.9 100\* 59.8 16.9 0.020 GIN R 40 4.65 1.00 50 6.22 1.40 <0.001

*n = number, \* = number of ears, B = both, R = right, L = left;* ∑ *= mean, SD = standard deviation, DD = dichotic digits,* 

*Behavioral evaluation values of central auditory processing between control and experimental groups.*

**N ∑ (%) SD N ∑ (%) SD** *p***-value**

L 40 97.93 4.15 50 92.55 7.95 <0.001

L 40 4.72 1.06 50 6.56 1.52 <0.001

**Procedure Ear Control group Experimental group**

*SSI = synthetic sentence identification, FPT = frequency pattern test, GIN = gaps-in-noise.*

have been too long **Table 1**.

regardless of socioeconomic status.

performance in the DD and GIN responses than in normals.

development of spatial processing in the CANS.

**3.2 Electrophysiological evaluation**

used [27].

FPT

**70**

**Table 1.**

In the literature, there are contradictory results in Click ABR responses in individuals with a history of OM. Chambers et al. [28] and Folsom et al. [29] identified an increase in the latency of waves III and V in a group of children with a history of OM, whereas Shaffer [30] did not find a statistically significant difference in Click ABR responses in individuals with and without a history of OM. The majority of studies relating Click ABR results with OM history have investigated latency values; however, Maruthy and Mannarukrishnaiah [31] found a reduction in the amplitude of waves I and III. Sanfins et al. [32] observed statistically significant differences in the absolute latencies of waves I and V as well as in the amplitude of waves III and V from children with a history of bilateral OME compared to their healthy peers. Colella-Santos et al. [11] reported a significant increase in the absolute latency of wave III associated with a decrease in amplitude in children with bilateral OME. Finally, Sanfins [33] reported alterations in the values of waves III and V for both groups of children with a history of OME, seeing both bilateral and unilateral alterations **Figure 3**.

In animals, the effect of conductive hearing loss on CANS was studied by unilaterally removing the malleus and applying a fluid to simulate OM [34], finding a decrease in neuronal activity due to changes in various structures (wave III), upper olivary complex (wave IV), and lateral lemniscus (wave V). At the same time, based on the results of Maruthy and Mannarukrishnaiah [31], it has been suggested that the auditory nerve and cochlear nuclei are more susceptible to modifications after OM infection.

Sanfins et al. [32] suggest that different modifications may occur in CANS structures depending on the unilaterality or bilaterality of the infection. In episodes of bilateral OME, the latency values indicated that the auditory nerve (wave I, wave III) and the lateral lemniscus (wave V) were affected, whereas in unilateral OME, the cochlear nuclei (wave III) was affected. However, when the amplitudes were analyzed, the structures involved were the cochlear nuclei (wave III) and the lateral lemniscus (wave V), both for children with unilateral and bilateral involvement. It should be noted that when evaluating click ABR, the amplitude values show greater variability than the latencies. It is important to emphasize that a unilateral OM may not provide a better performance in the processing of auditory information than bilateral OM. The use of only one ear can lead to damage to the functionality of

**Figure 3.** *Click ABR. Personal collection.*

the CANS and, over time, activities that depend on binaural auditory processing (binaural interaction and binaural integration, among others) can be compromised due to the auditory imbalance arising from OM.
