Hearing Loss and Speech Perception Week 2

These flashcards cover the primary and secondary effects of hearing loss, methods for estimating speech intelligibility, and Arthur Boothroyd's classification of hearing loss groups based on auditory capacity and clinical outcomes.

Primary Effects of Hearing Loss

The direct results of hearing loss, such as loss of audibility, loss of sensitivity to sounds, and distortion of the signal.

Secondary Effects of Hearing Loss

The indirect results of hearing loss and other factors, such as delays in speech and language development and social implications.

Articulation Index (AI) / Speech Intelligibility Index (SII)

A weighted estimate of speech intelligibility expressed as a number between $0.0$ and $1.0$, where $1.0$ is completely intelligible.

Distortion

A factor that occurs when speech recognition is poorer than predicted based on audibility, potentially involving neural hearing loss or damage to auditory nerve fibers.

High Context Stimuli

Redundant stimuli with many linguistic cues, such as simple sentences, which require less audibility to be understood.

Low Context Stimuli

Stimuli with limited linguistic cues, such as nonsense syllables, which require higher levels of audibility for accurate perception.

Arthur Boothroyd’s Hearing Loss Groups

A grouping system for children with sensory hearing loss based on audibility and auditory resolution, used to understand outcomes with hearing aids and cochlear implants.

Boothroyd Group I (Mild)

Loss of $15$ to $45~dB$; auditory resolution is good, and children typically develop oral language spontaneously, though they are susceptible to noise and reverberation.

Boothroyd Group II (Moderate)

Loss of $50$ to $70~dB$; partial audibility of conversational speech unaided, but significant delays may occur without hearing aids, which can restore full audibility.

Boothroyd Group III (Severe)

Loss of $70$ to $90~dB$; conversational speech is not heard unaided, and children do not develop oral language spontaneously; they may be candidates for a cochlear implant (CI).

Boothroyd Group IV (Profound)

Loss of $90$ to $110~dB$; only partial audibility is restored with amplification, and the listener is limited to prosodic features and speechreading.

Boothroyd Group V (Total)

Loss of $110~dB$ or more; sound is perceived via the sense of touch rather than hearing, and oral language acquisition requires intensive habilitation and visual input.

Auditory Resolution

The clarity of the auditory signal; even if sounds are audible, reductions in resolution (distortion) can impact speech perception.

Age of Onset

A critical factor in the effect of hearing loss on communication, particularly regarding whether the loss is pre-, peri-, or post-lingual.

Frequency Importance for Intelligibility

The concept that certain frequencies contribute more to speech understanding, specifically that $1000-2000~Hz$ is more important than $10,000-20,000~Hz$.