6.1 loudness & intensity coding

dynamic range

a system is the range of levels our which he system operates to a certain standard performance

to determine the dynamic range of human hearing we need to know the lower & upper level limits of our ability to process sounds effectively

6.2.3 loudness scales

loudness matching can provide important information about how loudness influenced by some stimulus characteristics

(eg. frequency, bandwidth & duration)

can’t tell us how loudness changes w/ sound level

magnitude estimates & magnitude production

respectively have been used w/ some success o quantify the subjective experience of loudness

loudness = l. Kla

ll = loudness

l is intensity

k is constant

loudness is a compressed version of sound intensity

sensorineural hearing loss

hearing loss that arises from the destruction of the cochlea, the auditory nerve or the auditory pathways in the brain

• particularly prevalent in the elderly

• auditory neuropathy

  a mixed hearing loss - simply conductive loss in combination w/ a sensorineural loss

characteristics of cochlea hearing loss

damage to inner hair cells results in a loss of sensitivity sounds increasing the absolute threshold for sounds in the affect frequency region

loudness recruitment

damage to other hair cells results in a abnormally rapid growth in loudness level

outer hair cells require

a supply of oxygen & other nutrients to function. After detection, the response is more steeper and linear reflecting the passive response of basilar membrane in absence of outer hair cells activity.

Absolute pitch/ pitch

a few individuals here absolute or “perfect” pitch

pitch - which is the ability to name a musical note they hear w/out any other reference

Tone languages

depends on differences in fundamental frequency & on fundamental frequency transitions to distinguish words

the auditory scene - auditory system

auditory system requires a mechanism that can separate out the sound and compares the original from different sound sources and group together

the auditory scene

sounds compare that arise from the same sound source. Bregman (1990) has termed the whole process auditory scene analysis.

frequency comparer

using the spectral analysis powers of cochlea

simultaneous grouping

organizing sounds occur at the same time

sequential grouping (arranging sound sequences)

first however, we 100 at the principle that the auditory system uses to interpret the complex information arranging at our ears