Class Notes (806,815)
Canada (492,451)
Psychology (4,968)
PSYCH 3A03 (56)
Paul Faure (56)

Tutorial 11- Psychoacoustics Tutorial.docx

4 Pages
Unlock Document

McMaster University
Paul Faure

November 27 , 2013 Psych 3A03: Audition Tutorial 11: Psychoacoustics Tutorial Loudness Scaling - Subjective loudness scales as the question: how many times as loud is this sound relative to that sound - Subjective loudness scales are different from hearing thresholds and JNDs - Sone scale was derived from objective loudness ratings of listeners by S.S. Stevens - Sone scale reference point – 40dB SPL, 1000Hz  1 sone = 1000Hz @ 40 dB SPL  1 sone= 40 phons - Sounds rated as twice as lid as a 1 sone sound have a loudness of 2 sones - Sounds rated as three times as loud as 1 sone sound have a loudness of 3 sones - When plotted on a log-log scale, sone scale rises linearly with dB SPL over most of audible range - Sone scale doubles for every 10dB increase in SPL - We perceive ΔdB = 10dB SPL as being twice as loud Loudness Recruitment - Loudness scaling differs with testing conditions - Loudness recruitment is when loudness of a masked tone increase faster than loudness of unmasked tone - Slope >10dB SPL per sone - 40dB = equal loudness point - 80dB = equal loudness point - 40dB conductive hearing loss: loudness recruits more steeply than 10 dB for a doubling and reaches 80dB to reaching normal hearing - Loudness recruitment thought to be useful for understanding how loudness changes in people with a hearing loss Loudness Adaptation - Loudness adaptation, also called peristimulus fatigue, occurs to exposure of long duration (s or min) sounds - A change in loudness occurs during stimulus presentation (i.e. sounds appear softer the longer they have been on) - When adapting stimulus remains on for longer periods of time, it has been shown (with matching procedures) that Ss decrease the level of the matching stimulus - Thus, loudness decreases with time - Context affects perceived loudness (e.g. rock concert) Neural Coding of Loudness - Active areas of research; neural mechanisms of loudness processing by CANS still not fully understood - Mechanisms assumed to be involved in loudness psychophysical measures (e.g. intensity discrimination) - Assumption: related to total evoked neural activity - If true, then loudness is related to the activity of neurons whose CF are the same or near the stimulus frequency Pitch Perception - Pitch is not easily defined. Pitch is a subjective sound attribute, defined in terms of what is hear - Defined formally as:  That attribute of auditory sensation in terms of which sounds may be ordered on a musical scale - Scaled differently in different cultures - E.g. Western tonal scale, Chinese tonal scale - Relationship of frequency to pitch is predicted based on encoding of sound frequency by cochlea and ANFs (temporal theory), or more generally by the tonotopic organization of the auditory system (place theory) - Pitch perception is correlated with stimulus frequency:  Pure tones (sinusoid): pitch = frequency  Periodic complex tone: pitch is fundamental frequency  Pitch perception also related to physical repetition rate of stimulus waveform  Increasing stimulus repetition rate gives the sensation of increasing the pitch of the stimulus Stimulus level and bandwidth also alter pitch perception - Appropriate variations in stimulus repetition rate gives the sensation of melody - Variations in
More Less

Related notes for PSYCH 3A03

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.