# Intro to Hearing Science and Hearing Disorders Will Styler - LIGN 113 --- ### The Plan - What is sound? - What is hearing? - What are we covering? - What are we skipping? --- ### What is sound? ![](phonmedia/sound_diagram.jpg) --- ![](phonmedia/slinky_wave.jpg) --- ## Sound is compression and rarefaction in a medium - Sound needs something to travel in (like air or water) - Without a medium, no sound --- ### (Yes, your childhood is a lie) ![](humorimg/star_wars_battle.jpg) --- ### Thinking of sound as waves is helpful - How do speakers work? - Why does clapping cause a sound, but waving your hand through the air doesn’t? - Why are gunshots loud? - If a tree falls in the forest and nobody's around to hear it, does it still make a sound? --- ### Sound has two main properties we care about for hearing - Amplitude/Power ("Loudness") - Frequency ("Pitch") --- ### Amplitude/Power ("Loudness") - High amplitude = Loud ![](phonmedia/sound_diagram.jpg) --- ### Frequency ("Pitch") - Low frequency == Low pitch ![](phonmedia/sound_diagram.jpg) --- # What is hearing? --- ### Hearing is a perceptual process - Turning pressure variations in the audible range into their perceptual reflex - A monolithic signal enters the ear, but a frequency-organized signal enters the mind - **This is not a linear, clean mapping!** - This signal is (usually) **binaural**, coming from both ears --- ### We can then turn this signal into a schema of the world --- ### Hearing is amazing
--- ### Hearing is amazinger
--- ### We use hearing for amazing things - Am I alone here? - Am I in danger? - "Is that sound real, or being played back by speakers?" - "Something doesn't sound right..." - "Are you OK?" --- ### ... but that doesn't mean hearing is perfect, either - It is fragile - It changes over time - It is limited - We don't hear sounds exactly as they are --- ### Do we hear frequency in a linear and reliable way? Is the jump in file A the same as in file B? A.
B.
A.
B.
--- ### Do we hear frequency in a linear and reliable way? Is the jump in file A the same as in file B? A. 400Hz - 600Hz
B. 10,400Hz - 10,600Hz
A. 400Hz- 500Hz
B. 6400Hz - 6500Hz
--- ### So, hearing can be studied in a few different ways - Anatomically (What are the physical structures?) - Acoustically (What are we hearing?) - Physiologically (How does this work in the body?) - Behaviorally (How do we respond to sound?) --- ## Hearing Science Scientific study of the structures, mechanisms, functions, and behavioral results of human hearing --- ### ... but hearing relies on many complex structures and systems - So it can fail! --- ## Hearing Disorders Physiological or Physical diseases, conditions or traumas resulting in sub-normal hearing ability --- ### This course is structured broadly in six main segments - Anatomy of Hearing - Acoustics - Physiology of Hearing - Psychoacoustics - Hearing Disorders and Testing - Hearing Interventions --- ### Anatomy - What are the structures of the ear? - How are they connected? - How do we divide the ear into subparts? - *What elements of human anatomy are important for hearing?* --- ### Acoustics - What is sound? - What are its characteristics? - How is it transmitted? - How can we visualize, measure, and understand sound? - What sounds and parts of the sound spectrum are most important for quality of life? - *What is hearing picking up on, anyways?* --- ### Physiology - How does the ear *work*? - How does the cochlea work? - What reflexes, phenomena, and physiological processes aid, protect, and influence hearing? - How is auditory information transmitted to the brain? - What happens once it's there? - *How does hearing work in humans?* --- ### Psychoacoustics - Are we perceiving sounds as they really are in the world? - How do we perceive acoustic phenomena like pitch and loudness? - How is hearing *non-linear*? - How can we tell where sound is coming from in the world aroud us? - *How are we processing and intepreting our auditory input?* --- ### Hearing Disorders and Testing - What are common causes of hearing loss? - What physiological processes are affected by various disorders? - Where do these disorders come from? How do they develop? - How can we identify and diagnose them? - What is the role of audiologists in this process? --- ### Hearing Interventions - What methods are used to treat hearing disorders for patients who feel that desire? - What medical interventions exist? - What surgical interventions exist? - How do hearing aids work? Who do they help? - How do cochlear implants work? What are their downsides - *What causes hearing loss, and how can it be treated for folks who want that?* --- ## One big note --- ### This course will take a clinical, treatment-focused approach - We will take a more medical approach, 'restoring towards common function' - We will refer to deafness and hearing loss as 'disordered' - We will talk about 'treating' hearing loss - We will discuss Cochlear implants and Hearing Aids and their effects on quality of life - This is because this is the approach taken in most Audiology programs! --- ### This *does not* mean this is the 'correct' attitude or approach - There are many perspectives, particularly within the Deaf community, on hearing 'loss' and hearing 'treatment' - It's not great to call an element of somebody's identity a 'disorder' - Understand that the point here is to understand the systems in play - Such that you can later help guide people towards the best choices for them - We'll talk more about this Friday! --- # What won't we be covering this quarter? --- ### Topics we're skipping in Anatomy - Greater biological processes supporting hearing - Anything at the other end of the auditory nerves - Surrounding anatomy of the head and neck - Anything developmental! --- ### Topics we're skipping in Acoustics - Electronic filtering - Digital Signal Processing and Digital Enhancement of Audio - Infrasound and 20,000Hz+ noise - Electrical Engineering for hearing science --- ### Topics we're skipping in physiology - Processing of auditory signals inside the brain - Development and growth of the auditory system - Fine details of the vestibular functions --- ### Topics we're skipping in psychoacoustics - Musical psychoacoustics (e.g. missing fundamentals, sound 'aesthetics') - Applied psychoacoustics (e.g. music therapy, product design, etc) - Behavioral differences associated with assisted and CI hearing --- ### Topics we're skipping in hearing disorders - Many, MANY less common disorders - Auditory Processing Disorders - (Most) trauma-related loss --- ### Topics we're skipping in hearing interventions - Hearing aid fitting - Cochlear implant configuration, training, and adjustment --- ### Do you have any other curiosities? - What else would you like to learn about hearing? - Even if it's been discused as 'skipped'? --- ### This quarter... - We'll talk about the ears - Sound - How we're able to hear - ... and what it's like when it goes right, and wrong! --- ## For Next Time - Differing perspectives on hearing science, and the importance and compassion and choice - **Please do the reading on Canvas** ---
Thank you!