09 Introduction to Hearing(1)

# 09 Introduction to Hearing(1) - 1 Introduction to Hearing...

This preview shows pages 1–4. Sign up to view the full content.

10/25/2016 1 Introduction to Hearing WEEK 9 Lecture outline Sound Physical characteristics Perceptual characteristics Hearing Physiology of the ear Sensation Cortical Organization A1 Tonotopic map Sound Sound Sound is not out there Pressure waves “sound waves” ugh Air particles (but also, water, ground, anything that vibrates) Sound is our perception of those waves Transduction of pressure waves into electrical signals Temporal coding: Information is in the timecourse of sensation Sound: Physical properties Frequency Number of cycles in one unit of time Compression: ↑ pressure Rarefraction : ↓ pressure Hertz (Hz): Number of cycles in 1 second Amplitude Intensity or amount of change in pressure Micropascals ( μ Pa) Decibel (dB) 1 2 3 4 5

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
10/25/2016 2 Compression & Rarefraction: Air Compression & Rarefraction: Water 44Hz Different frequencies Frequency Different Amplitudes Amplitude Different frequencies & ‘ tudes Decibel (dB) There is a wide range of audible pressure changes Decibel (dB) Different intensities can be orders of magnitude different If purring = 1 Talking = 10 Rocking = 100,000 Launching = 1,000,000 dB is a unit of measure that scales down the difference Logarithm Decibel (dB) dB = 20 x log 10 ( p / p 0 ) 20 = 20 log 10 = “logarithm of base 10” p = pressure of the wave (micropascals) p 0 = a reference pressure (usually 20 micropascals) Decibel (dB) dB = 20 x log 10 ( p / p 0 ) If an object creates pressure waves of 1000 micropascals: 6 7 8 9 10 11 12 13 14 15 16 17
10/25/2016 3 dB = 20 x log 10 (1000/20) dB = 20 x log 10 (50) dB = 20 x 1.70 dB = 34 SPL Decibel (dB) dB = 20 x log 10 ( p / p 0 )

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern