The Human Earfancy sub-heading

Parts of the ear

• Three main parts:• The outer ear consists of the

pinna, ear canal and eardrum

• The middle ear consists of the ossicles and ear drum

• The inner ear consists of the cochlea, the auditory (hearing) nerve and the brain

How it works

Sound waves enter the ear canal and make the ear drum vibrate.

This action moves the tiny chain of bones (ossicles) in the middle ear.

The last bone in this chain ‘knocks’ on the membrane window of the cochlea and makes the fluid in the cochlea move.

The fluid movement then triggers a response in the hearing nerve.

Ossicles

• The ossicles (also called auditory ossicles) are three bones in the middle ear that are among the smallest bones in the human body. They transmit sounds from the air to the cochlea.

• The term "ossicle" literally means "tiny bone" and, though the term may refer to any small bone throughout the body, it typically refers to the malleus, the incus and the stapes of the middle ear (Latin).

Youtube

• Now is a good time to watch this

• https://youtu.be/7O-adw-HyrQ

• More detailed video

• https://www.youtube.com/watch?v=46aNGGNPm7s

What does a sound wave look like?

…more pictures

Some numbers

• Sound travels at approx 345m/s (1,236kph) but this can vary with factors such as air pressure, temperature and altitude.

• Humans can hear roughly in the range of 20Hz to 20,000Hz

Hz?

• Hz or Hertz is a unit of frequency.

• It is the number of times a complete cycle happens per second

FREQUENCY!

• Frequency is measured in Hz.

• Lets listen to some frequencies!

• http://plasticity.szynalski.com/tone-generator.htm

• Tone generator activity

Relationship between Frequency and Pitch

• The frequency range of 20Hz to 20kHz is equivalent to about 10 octaves in pitch.

• An octave on a piano equals 12 notes (semitones).

• The higher the frequency the higher the pitch.

• A4 on a piano is 440Hz, therefore A5 is 880Hz and A3 is 220Hz

• Every increase in pitch by 1 octave = double the frequency.

• Every decrease in pitch by 1 octave = halving the frequency.

• There’s maths happening here!

• http://virtualpiano.net/

• https://www.youtube.com/watch?v=W_Ob-X6DMI4 (What Phi Sounds Like )

Amplitude

• Amplitude is the degree of change (positive or negative) in atmospheric pressure (the compression and rarefaction of air molecules) caused by sound waves.

Sound Waves

• Sound energy travels in waves and is measured in frequency and amplitude.

• Amplitude measures how forceful the wave is. It is measured in decibels (or dBA) of sound pressure.

• 0 dBA is the softest level that a person can hear. Normal speaking voices are around 65 dBA. A rock concert can be about 120 dBA.

• Sounds that are 85 dBA or above can permanently damage your ears. The more sound pressure a sound has, the less time it takes to cause damage. For example, a sound at 85 dBA may take as long at 8 hours to cause permanent damage, while a sound at 100 dBA can start damaging hair cells after only 30 minutes of listening.

You don’t even have to remember this slide

Compare some waveforms for frequency and amplitude

• Tristam couldn’t find pictures so he’ll have to draw some…

• Hearing safety• Ear plugs• Connecting equipment

correctly

DAW

• A digital audio workstation (D.A.W.) is an electronic device or computer software application for recording, editing and producing audio files.

• Eg:• Audacity (Free)• Audition (Part of Adobe Creative Suite)• Pro Tools (Industry standard)

Adobe Audition

• Editing audio files• Record, select, cut, copy paste.