Can't hear or can't hear?
A few words about what depends on the correct reception and processing of sounds.
CONTENT:
Evaluation of the function of the peripheral auditory system - hearing dynamics
Evaluation of the function of the peripheral auditory system - speech understanding
Assessment of the dynamics of hearing - the level of speech understanding in noise.
Evaluation of the function of the peripheral auditory system - hearing dynamics
"I have to call them several times"
"He can't concentrate on what I'm telling him"
"He doesn't understand what I'm telling him"
"He speaks loudly, he acts loudly"
"Everything is already tired"
"I will not sit in one place for a minute"
"Complains it's too loud"
The above-mentioned descriptions of children's behavior are often emphasized in the context of children's difficulties with the development of speech, literacy, learning in general, etc. emotional and social functioning.
Could they have something to do with hearing?
This is easy to check. In younger children, a basic hearing test, i.e. pure-tone audiometry, can be performed, and based on this, it can be assessed whether the child's hearing threshold is correct.
Hearing threshold - the smallest value of sound intensity [atmospheric pressure] that causes hearing. In other words, the quietest sounds we can hear.
And often it turns out to be RIGHT.
The question is, is enough? Does it give us a complete picture of how our child functions in a world full of sounds?
Definitely NOT!
To properly assess a child's auditory function, the entire auditory system must be considered. It is not only the hearing organ itself. The system consists of peripheral and central parts.
The peripheral part includes the outer ear, the middle ear, and the cochlear part of the inner ear with the spiral. The central part starts from the second neuron in the cochlear nuclei in the medulla oblongata to the cortical center in the brain.
According to the above-mentioned part, two processes can be distinguished during the auditory process. The first is HEARING, that is, the correct perception of a sound signal [e.g. language], which deals with the transmission of impulses to the central nervous system. The second is LISTENING, that is, the correct use of these signals, that is, their recognition, interpretation, memorization, etc.
To assess how the peripheral part of the auditory system functions, it is not enough to determine the hearing threshold. All HEARING DYNAMICS must be evaluated.
The dynamics of hearing is a dynamic process associated with transformations that occur from the moment a sound wave enters our ear to the moment the impulse reaches the central auditory system.
The limits of hearing dynamics are determined by two parameters. The first of them is the already mentioned hearing threshold. Its normative values are 0-20 dB HL.
dB is a unit of measurement of sound intensity
The upper limit of the no. the threshold of auditory discomfort, i.e. the situation when the presented/heard sound is perceived as too loud, unpleasant. Its normative values are 90-100 dB HL.
The hearing threshold shows us the quietest sounds we can hear, and the auditory discomfort threshold determines the sounds that are too loud for us and cause us discomfort.
UCL is an uncomfortable sound level
If the hearing threshold results reach values above 20 dB HL, we can talk about hearing loss. The degree of hearing loss depends on the values obtained during pure-tone audiometry. If the results of the auditory discomfort threshold are below 90 dB HL, we can talk about auditory hypersensitivity.
Evaluation of the function of the peripheral auditory system - speech understanding
The next two parameters we can test are speech understanding and speech in noise.
Speech audiometry [verbal audiometry] is a test that consists in repeating syllables, words or sentences presented in headphones. This allows us to assess social ability, that is, the ability to communicate in everyday life through verbal communication. In speech audiometry, two parameters are usually determined. SDT speech detection threshold and SRT speech perception threshold.
The result of a verbal audiometry test is a discrimination curve that shows the percentage range of speech understanding at a given level of stimulus intensity, that is, what percentage of words presented at a certain volume [intensity] the subject could repeat. As a normative value, it is most often accepted that if monosyllabic words are given at a volume level of 40 dB HL, the examinee must repeat 100% of the presented words. Speech audiometry is performed in special audiometric headphones with air conduction. The test is performed separately for the left and right ear. This is a non-invasive test, but requires the cooperation of the patient.
Verbal audiometry in the form of pictures can be performed in younger children, who are less cooperative, with articulation disorders or delayed speech development (of various etiologies). This form of research is more understandable and attractive for a child. This affects the understanding of the testing procedure itself, but, above all, increases the child's interest and motivation to perform the task. In this version of the examination, the child's task is to indicate the appropriate picture in the free auditory field based on auditory information provided through headphones or loudspeakers.
A free-field audiometric test determines the ability to understand speech at different levels of intensity. They are conducted using loudspeakers connected to an audiometer placed at a distance of about 1 m on both sides of the subject.
Assessment of the dynamics of hearing - the level of speech understanding in noise
The last parameter that must be included in the complex of hearing dynamics assessment is the level of speech understanding in noise.
Speech in noise audiometry allows you to determine the degree of speech understanding depending on the intensity of the acoustic background.
Therefore, in order to evaluate a child's HEARING, it is not enough to just check the hearing threshold. Doing a few more tests can give us a lot of information and often explain the problems our child is having. In everyday reality, we all spend most of our time in the so-called acoustic background. Sounds accompany us all the time. We cannot turn them off. If your child has difficulty understanding language, this will have a significant impact on their behavior at home and at daycare/school. Very often this behavior is related to educational or emotional problems. Meanwhile, the typical symptoms that indicate the possibility of hearing disorders in a child are quite easy to spot. They include:
delayed response or no response to calls,
distraction and concentration problems,
looking around the room/class while the others follow the teacher's instructions,
worse understanding of commands in noise, for example, during a break between lessons,
please repeat the statements,
difficulty understanding the question
delayed speech development,
limited language resource,
constant problems with articulation,
problems with mastering the skills of reading and writing [technique and comprehension of the read text], problems with writing [especially listening - the child writes as he hears),
inaccurate pronunciation of words: dropping the beginning or ending [of words], transformation of words, confusing them by sound or semantic similarity,
observing the face, in particular the mouth of the speaker,
frequent unpreparedness for lessons due to the child not writing down the homework topic,
sitting too close to the TV or turning up the volume too high
sit close to the teacher and look attentively or vice versa - disturb at the end of the room,
emotional problems: difficulties establishing contacts, functioning in a group,
talk loudly, squeak, make different sounds,
sitting in class during recess,
avoid loud noises
reports of headaches, which may be a symptom indicating the presence of hypersensitivity or hearing fatigue,
hear sounds that others do not hear (buzzing, squeaking, whistling, ringing),
feeling of ear congestion,
disequilibrium.
That is why it is so important to assess the child's level of individual parameters included in HEARING DYNAMICS as early as possible.
