#human ear

Steno, or Niels Steensen (Jan. 1., 1638 - 1686) was a Danish scientist and saint. He founded the discipline of geology by studying fossils such as shark teeth in the Italian mountains and clarifying stratification phenomena in the new science of stratigraphy. He also contributed significantly to the field of anatomy, esp. the anatomy of the human ear.

Later in life he converted to Catholicism and in 1988 was beatified by Pope John Paul II.

Human inner ear organs grown: Could lead to new therapies for hearing, balance impairments

Researchers at Indiana University School of Medicine have successfully developed a method to grow inner ear tissue from human stem cells -- a finding that could lead to new platforms to model disease and new therapies for the treatment of hearing and balance disorders.

"The inner ear is only one of few organs with which biopsy is not performed and because of this, human inner ear tissues are scarce for research purposes," said Eri Hashino, PhD, Ruth C. Holton Professor of Otolaryngology at IU School of Medicine. "Dish-grown human inner ear tissues offer unprecedented opportunities to develop and test new therapies for various inner ear disorders."

The study, published online May 1 in Nature Biotechnology, was led by Karl R. Koehler, PhD, assistant professor in the Department of Otolaryngology and Head and Neck Surgery at IU School of Medicine, and Dr. Hashino in collaboration with Jeffrey Holt, PhD, professor of otology and laryngology at Harvard Medical School and Boston Children's Hospital. The research builds on the team's previous work with a technique called three-dimensional culture, which involves incubating stem cells in a floating ball-shaped aggregate, unlike traditional cell culture in which cells grow in a flat layer on the surface of a culture dish. This allows for more complex interactions between cells, and creates an environment that is closer to what occurs in the body during development, Dr. Koehler said.

Karl R Koehler, Jing Nie, Emma Longworth-Mills, Xiao-Ping Liu, Jiyoon Lee, Jeffrey R Holt, Eri Hashino. Generation of inner ear organoids containing functional hair cells from human pluripotent stem cells. Nature Biotechnology, 2017; DOI: 10.1038/nbt.3840

Scientists 3D Print an Entire Human Ear in Lab

The unthinkable has happened. Researchers have managed to develop a 3D printer that is capable of bioprinting tissues to be used in transplants. These transplants can include muscle, bone, cartilage and even an entire human ear, which is precisely what the team has achieved.

The study has been published by researchers at Wake Forest Institute for Regenerative Medicine and has provided modern…

Tip for drawing ears

WEEK ONE:

The Human Ear

eardrum 

cochlea with basilar membrane inside which resonates with the vibrations as they come through

cilia or tiny hairs within the membrane which moves every time part of the membrane vibrates

higher frequencies are picked-up by the smaller part of the membrane while lower frequencies are picked-up by the larger part of the membrane

our brains can only make sense of about 16 to 20,000 vibrations per second

our brains are somewhat converting physical energy to electrical energy

Six Properties Of Sound / General classes of Auditory events

Pitch (Frequency) - steady state of vibration in the air

Loudness (Amplitude) - how much energy is contained

Timbre - multiple frequencies with variable amplitudes happening simultaneously (or colors of sound)

Duration - either perceived as slow or fast (generally always in reference to human heart beat)

Reverberant environment or Articulation (Envelope)  - 1st few milliseconds of a sound (attack - sustain - release)

Difusion (Spatialization) - detects direction as to where a sound is coming from

Overtone Series

simultaneous sounding of a particular fundamental frequency plus divisions of that in various ratio

Music and the Human Condition and the Environment

Music and Evolution:  Music promotes group cohesion

- strengthens emotional bonds between mother and child - music can transmit emotional information to many individuals at once

Music and Evolution:  Socio-Emotional Bonding

- music activates cognitive domains involved in speech - music and dance act as indicators of group stability

Music and Evolution:  Music Promotes Sexual Selection

- Charles Darwin proposed that the evolution of music in humans had its roots in courtship songs

Music In Emotional & Cognitive Development

- 2 months old; prefer consonant to dissonant - 3 year old; recognize happy in music - 5 year old; happy vs sad, basic pitch detection - 6 year old; sadness, fear & anger, detects keys and harmony - formal music training; increased spatial & quantitative reasoning as well as efficiencies in cognitive functions

Auditory Roughness

high ratio partials, highly unstable

amplitude fluctuations of the spectrum

pitch instability

high degree of sonic information in-between pitch areas

Dimensions of Musical Affect

Positive Valence - Low Activity = Tenderness

slow mean tempo, low sound level & small sound, soft legato articulation, timbre slow tone attacks, large timing variations, accents on stable notes, soft duration contrasts, final ritardando

Positive Valence - High Activity = Happiness

fast mean tempo & little tempo variability, high sound level & little sound level variability, staccato, bright articulation & large articulation variability, timbre fast tone attacks, small timing variation and sharp duration contrasts

Negative Valence - High Activity = Fear or Anger

FEAR, very low sound levels & large sound level variations, staccato articulations, fast mean tempo & large tempo & timing variations, fast, shallow, irregular vibrato

ANGER, sharp timbre, large vibrato, spectral noise, abrupt tone attacks, accents on unstable notes, no ritardando, fast mean tempo & little tempo variability, high sound level, staccato articulation and sharp duration contrasts

Negative Valence - Low Activity = Sadness

dull timbre, small articulation variability, slow vibrato, slow mean tempo, low sound level, legato articulation, slow tone attacks, large timing variations, soft duration contrasts, final ritardando

3 elements of soundscape

Keynote sounds - may not be heard consciously, but they outline the character of the people living there, they are created by nature: wind, water, forests, plains, birds, insects, animals (ex. in many urban areas, traffic has become the keynote sound

Sound signals - foreground sounds, which are listened to consciously (ex. warning devices, bells, whistles, horns, sirens, etc.)