case_images: PMC11404838_01
case_images: Neural response of the two promediations observed at 80 dB nHL and 30 dB nHL in both ears with the click stimulus (in blue left ear and red right ear) of the BAEP
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case_images: At 30 dBnHL, the V wave was observed bilaterally, with reproducibility from two sequential measurements which, when added together, can be seen on Figure 1. 
case_images: Experimental design of speech stimuli
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case_images: Each syllable lasted for 300 ms, with an initial rate of 48 kHz.The stimuli were organized and presented using Psychopy, an open-source software written in Python for research in neuroscience.The /ba/ and /da/ audios were edited in the Audacity program (Audacity  Cross-Platform Sound Editor), a open-source tool for digital audio editing, in order to adjust the sampling rate to 44.1 kHz and adapt it to Psychopy's sampling rate.This software enables synchronization between the present stimuli and the concurrent acquisition of functional near-infrared spectroscopy (fNIRS) data, thereby facilitating precise temporal alignment between the two modalities.Figure 2 shows the experimental stimuli design, in which 10 blocks were run for 53 minutes.
case_images: (A) Positioning of the optodes on the infant's head; (B) Arrangement of the optodes in the temporal lobe. In both, red are the emitting optodes, blue the detectors. In B, the purple lines represent the channels formed.
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case_images: The fNIRS cap was put on, consisting of 16 optodes (8 sources and 8 detectors) forming 20 channels (10 per hemisphere) separated by 3 cm (Figure 3A). All were positioned in the temporal lobe (Figure 3B), with the region of interest (ROI) being anterior, middle and posterior. Before starting the stimuli presentation, EAR-Tone ER 3C insert earphones (10 ohms) were plugged into each external acoustic meatus (Figure 3A). In relation to the (CH) channels, higher theta values can be seen in CH2, CH3, CH4 (anterior region of the HE) and CH13, CH12 and CH14 (anterior region of the HD) (Figure 3B, Table 3) of both stimuli.
case_images: (A) Average HbO (in red) and HbR (in blue) levels of the response to the /BA/ and /DA/ stimuli in the anterior (frontal) ROI on the right; (B) Average HbO (in red) and HbR (in blue) levels in response to /BA/ and /DA/ stimuli in the anterior (frontal) ROI on the left; (C) Average HbO (in red) and HbR (in blue) levels in response to /BA/ and /DA/ stimuli in the medial ROI on the right. (D) Average HbO (in red) and HbR (in blue) levels of the response to the /BA/ and /DA/ stimuli in the medial ROI on the left; (E) Average HbO (in red) and HbR (in blue) levels of the response to the /BA/ and /DA/ stimuli in the posterior ROI (back) on the right; (F) Average HbO (in red) and HbR (in blue) levels of the response to the /BA/ and /DA/ stimuli in the posterior ROI (back) on the left. DeltamuMol - micromolar
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case_images: In both ROI and channel analysis, there was no difference in the HbO theta value of the clinical case presented as a function of the stimuli used (Figure 4A-F).