Transcript 6) Hearing and ipods

Hearing and ipods
Dr. Marshall Chasin,
AuD., M.Sc, Reg. CASLPO,
Aud(C),
Doctor of Audiology
Noise and Music
 Noise
exposure is “almost like music
exposure”
 Prolonged
exposure to 85 dBA will
eventually cause a permanent hearing
loss
Noise and Music
 “Prolonged
 40
exposure…”
hours per week at 85 dBA
 20 hours per week at 88 dBA
 10 hours per week at 91 dBA
 5 hours per week at 94 dBA
 ….
Listening with one ear…
 We
all have a natural advantage when we
listen with two ears.



The music/speech is 6 decibels louder
The music/speech is 10% clearer
…. So, when listening with one earphone, the
volume needs to be 6 dB louder (which is four
times the damage).
Noise and Music

Nobody listens to music for 40 hours/week

BUT,… people do listen for 2 hours/day (ASHA
sponsored Zogby International poll, March 2006)


1000 adults and 301 high school students
AND, … depending on the volume setting, this
may be equivalent to a damaging dose…
From M. Chasin (2006)
The 60/120 Rule
The Fligor Rule (2006):
Maximum settings to obtain 50% maximum
dosage…

ipod volume at 60% for 120 minutes
 Depends on earphone used


Some earphones “isolate” the ear.
Some earphones have different electro-acoustic
characteristics.
From Fligor (2006)
The 60/60 Rule
 This
is appropriate for CD players
 These are about 3 dB more intense than
ipods.
 “60% volume setting for 60 minutes”
Portable music is portable…
 The
volume control is turned up in the
presence of background noise
 50%
volume control may be comfortable in
quiet, but this same comfortable listening
level may be 80% volume in noise.
Portable music is portable…

The “best” headphone is one that isolates you
from the environment…

You won’t need to turn up the volume control in
a noisy place.

BUT, you also lose warning cues!

BEWARE!!!
Zogby International (March ’06)
 69%
would turn down the volume.
 42%
would listen to music less often.
 36%
would wear special (isolator)
earphones.
So …
 60/60
rule for CD players
 60/120
rule for ipods
 Use
isolator earphones
 BUT
watch out for traffic!