Sonic Journey SlidesSonic Journey Deconstructing Sound Waves & Ear Anatomy The Physics of Sound Amplitude (Loudness) The height of the wave. Measured in decibels (dB). Higher waves = louder sound. Frequency (Pitch) The number of wavelengths in a period of time. Measured in Hertz (Hz). Shorter waves = higher pitch. Sound waves are compressions and rarefactions of air molecules. The Three Chambers of the Ear Outer Ear • Pinna: Visible part; channels waves • Auditory Canal: Tube leading inward • Eardrum (Tympanic Membrane): Vibrates in response Middle Ear Mechanical Conduction • Ossicles: Hammer (Malleus), Anvil (Incus), Stirrup (Stapes) • Transmits vibrations to the oval window Inner Ear Transduction • Cochlea: Snail-shaped, fluid-filled tube • Basilar Membrane: Contains hair cells • Auditory Nerve: Sends signals to Thalamus The Magic of Transduction 1 Vibrations hit the Oval Window This causes the fluid inside the snail-shaped cochlea to ripple. 2 Hair Cells Bend The fluid motion bends the tiny hair cells (cilia) on the Basilar Membrane. 3 Electrical Impulse This movement triggers an electrical signal sent via the Auditory Nerve to the Temporal Lobe.
Sonic Pathway WorksheetSonic Pathway Tracing Sound through the Human Ear Student: Date: 1 The Anatomy of Hearing Identify the structure described in each functional definition below. Structure Name Functional Role The visible "funnel" that captures sound waves and directs them inward. A thin membrane that vibrates when struck by sound waves. The three smallest bones in the body (Hammer, Anvil, Stirrup). The snail-shaped, fluid-filled structure where transduction occurs. Tiny sensory receptors that bend to trigger neural impulses. 2 The Path of Sound Trace the mechanical journey of a sound wave from the external world to the brain's temporal lobe. Fill in the missing steps. Sound Waves (Air) Pinna Auditory Canal Oval Window Temporal Lobe (Brain) 3 Wave Characteristics Amplitude Explain how a change in wave height affects our psychological perception of sound. Frequency Explain how a change in wavelength affects our psychological perception of sound.
Hearing Spectrum SlidesThe Spectrum of Sound Pitch Perception & Hearing Health Two Ways to Go Quiet Conduction Hearing Loss Damage to the mechanical system that conducts sound waves to the cochlea. Broken ossicles Punctured eardrum Treatable with hearing aids Sensorineural Hearing Loss Damage to the cochlea's hair cell receptors or to the auditory nerves. Aging / Prolonged loud noise Biological/Genetic factors Requires Cochlear Implants How do we hear High vs. Low? Place Theory We hear different pitches because different sound waves trigger activity at different places along the cochlea's basilar membrane. Best for High Pitches. Frequency Theory The brain reads pitch by monitoring the frequency of neural impulses traveling up the auditory nerve. Best for Low Pitches. The Fragility of the Hair Cell A hair cell is like a blade of grass. You can walk on it once, and it pops back up. Walk on it every day, and eventually, it stays flat. 85 Decibels The threshold where prolonged exposure causes permanent damage. Normal Conversation 60 dB Lawn Mower 90 dB Rock Concert 120 dB Jet Takeoff 140 dB
Hearing Diagnostics WorksheetHearing Diagnostics Clinical Case Studies in Audition Student: Date: Diagnostic Reference Conduction Loss Mechanical failure (eardrum/ossicles). Often fixed with surgery or standard hearing aids. Sensorineural Loss Receptor failure (hair cells/nerve). Often requires cochlear implants. 1 The Retired Drummer Elias, age 55, spent thirty years touring with a rock band. He recently noticed that he can no longer hear high-pitched sounds, like the chirping of birds or the "s" and "f" sounds in conversation. His doctor explains that years of exposure to 110dB speakers has flattened the cilia in the base of his cochlea. Identify the type of hearing loss: Based on Place Theory, why can't Elias hear high-pitched sounds? 2 The SCUBA Accident Maya suffered a rapid pressure change while diving, resulting in a small puncture in her tympanic membrane (eardrum) and a slight dislocation of the incus (anvil) bone. She describes her hearing as "muffled," as if she is underwater, but her inner ear remains perfectly healthy. Identify the type of hearing loss: Would a standard hearing aid (which amplifies sound vibrations) likely help Maya? Why or why not? 3 The Bass Guitarist Sam is a bass player who specializes in very low-frequency notes (below 100 Hz). According to **Frequency Theory**, Sam's brain determines the pitch of these low notes by monitoring the rate at which his auditory nerve fires. If Sam plays a note at 50 Hz, how many times per second would his auditory nerve fire according to this theory? Challenge: The Volley Principle Individual neurons can't fire faster than 1,000 times per second. How do we hear frequencies above 1,000 Hz if Frequency Theory is correct?
Chemical Connections SlidesChemical Connections The Science of Taste & Smell Gustation: The 5 Tastes Sweet Energy source Salty Sodium essential Sour Potentially toxic acid Bitter Potential poisons Umami Proteins/Savoriness Mechanism Taste is a chemical sense. Inside the bumps on your tongue (papillae) are 200+ taste buds, each containing a pore that catches food chemicals. Olfaction: The Direct Route ! Unlike all other senses, smell bypasses the Thalamus. It goes straight to the olfactory bulb. Smell & Memory The olfactory bulb is directly connected to the Limbic System (Amygdala & Hippocampus). This is why smells trigger intense emotions and memories. Neural Pathway Odor Molecules Olfactory Receptors Olfactory Bulb Limbic System (Emotion/Memory) The Flavor Equation Taste Chemicals on tongue Smell Aroma in nasal cavity = Flavor Brain's perception "Without smell, a strawberry is just 'sweet' and 'sour'."
Flavor Lab GuideThe Flavor Lab Testing the Limits of Gustation & Olfaction Researcher: 1 The Lifesaver Test Instructions: Plug your nose tightly. Place a flavored candy (like a Lifesaver or Skittle) on your tongue. Chew it while keeping your nose plugged. Try to identify the specific flavor. Observation A (Nose Plugged): What do you physically feel/taste? (Sweet, sour, etc.) Step 2: Release your nose and continue chewing. Notice the immediate change. Observation B (Nose Released): What happens to the perception of the candy? 2 The Tongue Mapping Supertasters have more fungiform papillae (the bumps on your tongue) and are more sensitive to bitter tastes. Answer the following questions honestly: 1. Do you find black coffee or dark chocolate intensely bitter? Yes No 2. Do you strongly dislike "bitter" greens like kale or spinach? Yes No 3. Are you particularly sensitive to spicy foods (heat)? Yes No 3 The Limbic Link Identify a specific scent (e.g., freshly cut grass, a certain perfume, old books) that triggers a vivid memory for you. Describe the memory and explain why this happens neurally. The Scent: The Neural Explanation (Why the bypass?):
Somatic Sensation SlidesSomatic Senses Touch, Temperature, & The Gate of Pain The Touch Toolkit All skin sensations are variations of these four primary receptors: Pressure The only sensation with specialized receptors. Warmth Triggers when temp increases. Cold Triggers when temp decreases. Pain Signals potential damage. Gate-Control Theory Pain isn't just "on" or "off." The spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass to the brain. Small Fibers: Open the gate (PAIN!) Large Fibers: Close the gate (Relief/Massage) Pain Modulation Why rubbing a bumped elbow makes it feel better. Cortical Magnification The Sensory Homunculus A visual representation of the Somatosensory Cortex. Body parts with higher sensitivity (hands, lips) take up more brain space. Density = Sensitivity Higher receptor density in fingertips means a smaller "Two-Point Threshold." Parietal Lobe The destination for all tactile signals. Endorphins Natural painkillers that help "close the gate" during intense stress or injury.
Tactile Mapping Lab GuideTactile Mapping Measuring Two-Point Discrimination Researcher: Background Different parts of your body have different densities of touch receptors. The two-point threshold is the smallest distance between two points that can still be felt as two separate sensations. A smaller threshold indicates higher receptor density and more "real estate" in the Somatosensory Cortex. 1 Procedure Equipment: One paperclip (unfolded into a U-shape) and a ruler. Steps: The Subject closes their eyes. The Researcher touches the skin with the two points of the paperclip. Start with points far apart and move them closer until the Subject feels only ONE point. Measure the distance (mm) of the last successful "two-point" detection. Test multiple body sites 2 Data Collection Body RegionTrial 1 (mm)Trial 2 (mm)Average ThresholdFingertipPalm of HandForearmBack of Neck 3 Analysis Based on your data, which body part has the largest area in the Somatosensory Cortex? Explain using the term "Cortical Magnification." Why might it be evolutionary advantageous for your fingertips to have a smaller two-point threshold than your back?
Sensory Symphony SlidesSensory Symphony Integration, Interaction, & Synesthesia The Integrated Brain Sensory Interaction The principle that one sense may influence another. Senses rarely work in isolation. The McGurk Effect A perceptual phenomenon that demonstrates an interaction between hearing and vision in speech perception. "What we see overrides what we hear." Interaction Examples Visuals + Flavor Sound + Balance Touch + Temperature Synesthesia: The Cross-Wire Definition A neurological condition where stimulation of one sensory pathway leads to automatic, involuntary experiences in a second sensory pathway. Grapheme-Color Seeing specific colors when viewing letters or numbers. Chromesthesia Seeing colors when hearing sounds or music. Embodied Cognition The influence of bodily sensations, gestures, and other states on cognitive preferences and judgments. Warmth & Trust Holding a warm drink makes people perceive others as "warmer" or more generous. Weight & Importance Holding a heavy clipboard makes job applicants seem more "serious" or important. "Our mind is not just in our brain; it's in our body."
Design Symphony Project PromptDesign Symphony Applying Sensory Interaction to Product Design Final Project The Challenge You are a **Multisensory Design Consultant**. Your task is to design a product, an environment, or an experience that intentionally uses **Sensory Interaction** and **Embodied Cognition** to influence human behavior or perception. Option A: The Space Design a high-stress hospital waiting room or a focused university library. Option B: The Product Design a luxury beverage container or a new "calm-tech" wearable device. Your Proposal Must Include: 1 Visual Concept & Mood How will lighting, color, or shape influence the user? (Connect to perception of warmth, weight, or size). 2 Auditory Atmosphere What frequencies or soundscapes will be present? How will they interact with the other senses? 3 Tactile or Chemical Integration Will there be a specific scent? A specific texture? How does this enhance the goal? Initial Brainstorming Core Goal (e.g., "Reduce Anxiety", "Increase Spending", "Improve Focus"): Sense 1: ________ Sense 2: ________ The "Interaction" Effect: How do these senses work TOGETHER to create the final perception? Evaluation Criteria Psychological Depth Correct use of interaction terms. Creative Application Novelty of design solutions. Professionalism Clarity and polish of proposal.
