Audiogram Degree, Type, Configuration

air conduction

we can classify the degree of hearing loss (different descriptive categories) based on the person’s _______ threshold values

normal

slight

mild

moderate

moderately severe

severe

profound

7 degrees of hearing loss

-10 to 15 dB HL

normal hearing loss

16 to 25 dB HL

slight hearing loss

26 to 40 dB HL

mild hearing loss

41 to 55 dB HL

moderate hearing loss

56 to 70 dB HL

moderately severe hearing loss

71 to 90 dB HL

severe hearing loss

91+ dB HL

profound hearing loss

attenuation

reduction in sound level (How much quieter a sound needs to be before it becomes difficult for someone with hearing loss to hear it)

The greater the hearing loss, the louder sounds generally need to be for the person to hear them

everyday situations

it’s important to consider how much the hearing loss affects someone's ability to understand speech and communicate in _________, not just the threshold number

slight

which hearing loss category is typically used in children

conductive hearing loss

loss of energy due to external and middle ear

sensory/neural hearing loss

loss of energy due to inner ear of 8th nerve

mixed hearing loss

loss of energy occurs due to problems in the external or middle ear, AND inner ear or 8th nerve

type of hearing loss

describes how the loss of sound energy or sound attenuation is occurring

The outer/middle ear and cochlea/auditory nerve are not damaged, and both AC and BC are normal

what is normal hearing?

The outer or middle ear is damaged, the cochlea/auditory nerve are not damaged, AC is impaired, and BC is normal.

What is conductive hearing loss?

The outer/middle ear is not damaged, the cochlea or auditory nerve is damaged, and both AC and BC are impaired.

What is sensorineural hearing loss?

The outer/middle ear and the cochlea or auditory nerve are damaged, and both AC and BC are impaired.

What is mixed hearing loss?

presence or absence of air bone gap

how do we determine the type of hearing loss?

AC value - BC value > 10dB HL

air bone gap is present if what? (AC is worse than BC)

yes

can ABG occur at any frequency

conductive (or mixed)

if an air bone gap is present, what type of hearing loss is present?

normal hearing

AC normal

BC normal

no ABG

conductive hearing loss

AC abnormal

BC normal

ABG gap present/abnormal

SNHL

AC abnormal

BC abnormal

no ABG gap

mixed hearing loss

AC abnormal

BC abnormal

ABG gap present/abnormal

mixed hearing loss

abnormal BC + ABG gap = ?

SNHL

abnormal BC + no ABG gap = ?

bone conduction thresholds

type of hearing loss is assigned based on _______ and hoe they relate to AC thresholds

pinna, ear canal, eardrum, middle ear

what structures are in external/middle ear?

basilar membrane, hair cells, auditory nerve pathway

what structures are in inner ear?

classical pattern of conductive hearing loss

Bone conduction is normal (≤25 dB HL), but air conduction shows hearing loss, with an ABG greater than 10 dB at every tested frequency

classical pattern of SNHL

Classical: AC and BC responses are worse than 25 dB HL and ABGap ≤ 10 dB HL from one another

variation pattern of SNHL

unable to measure BC due to limited audiometer output (testing equipment could not generate a loud enough vibration to test your bone conduction (BC) at certain high frequencies)

classical pattern mixed hearing loss

BC responses are worse than 25 dB HL, but they are > 10 dB HL better than the AC threshold at each pitch

variable pattern mixed hearing loss

One frequency has CHL, another pitch has SNHL, and another has mixed HL

central hearing loss, nonorganic hearing loss/pseudohypacusis

two other types of hearing loss that can’t be diagnosed with audiogram

central hearing loss

Once sound information reaches the brain, there is disorganization or inefficient processing of information that leads to loss of understanding.

-Not a “loss of energy,” but a loss of processing

-Causes: brain injury, neurological disorders, degenerative diseases, etc

Non-organic hearing loss/pseudohypacusis

No detectable physiological or structural damage in the ear or auditory system, but patient reports hearing problems

-Hearing loss may be exaggerated or faked, often due to external motives or psychological factors

configuration of hearing loss

attempts to describe the shape of the threshold line for each ear (how audiogram moves from one frequency to another)

flat, sloping/falling, rising, peaked/reverse cookie bite, cookie bite/trough, notched

types of configuration

flat configuration

< 5 dB change from frequency to frequency (per octave)

classical flat configuration

no more than 10 dB different across all pitches tested

variation flat configuration

maximum of 30 dB difference across 5 octaves

sloping configuration

5-12 dB change from frequency to frequency (best threshold occurs in low frequencies)

classical sloping configuration

gradual slope

variation sloping configuration

steep slope, precipitous slope or “ski slope”

rising configuration

> 5 dB change from frequency to frequency (best threshold occurs in the high frequencies)

classical rising configuration

gradual rise

variation rising configuration

steeper rise

notched configuration

≥ 20 dB loss at one pitch compared to adjacent frequencies (Best threshold in the high or low frequencies)

classical notched configuration

one frequency in the notch (3000 Hz)

variation notched configuration

multiple frequencies in the notch (2000-4000 Hz)S

cookie bite / trough configuration

≥ 20 dB loss at mids compared to highs & lows (best threshold in the high or low frequencies)

reverse cookie bite / peaked loss / tent

≥ 20 dB loss of highs & lows compared to mids (best threshold in mid-frequencies)

asymmetric Configuration

Different degrees of hearing loss between right and left ear

15 dB difference in air conduction values at 3 consecutive pitches between two ear

Example 1: 4000-8000 Hz right is ≥ 15 dB better than left

asymmetric Configuration

Different degrees of hearing loss between right and left ear

Some clinics also use 20 dB different at 2 consecutive frequencies, or ≥ 30 dB difference at one frequency

Example 2: 2000 Hz left ear is 45 dB worse than the right ear