7. Personal Listening Devices

Personal Music Players
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Rugby World Cup 2011
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321 Million iPods and 146 Million iPhones
sold as of October, 2011
Total Smartphone sales in 2011 - 488 million
across the globe, rising to 982 million in 2015.
15 Billion iTunes downloaded as of July, 2011
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Some 31% of kids ages 6 to 10 now use digital-music players
"By third grade, half of the kid population in grade school has an MP3 player,"
iPod use
• 36.1% teenagers and 44.6% of
young adults listened at 50-75%
max volume
Chang, 2010
• Piper Jaffray's Teen Survey
indicated that 92% of students
now own personal music systems
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iPod technology
• 160 GB of storage
• 36 hours of continuous music
• 200 hours of video
• Storage for 40,000 songs
• Over 100 dBA output volume
Are iPods/MP3 players
dangerous?
Well… how loud are they?
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101.8 dB
Portnuff & Fligor
Time limits using earbuds*
% volume
Max listening time/day
up to 60%
No limit
70%
6 hours
80%
90 minutes
90%
22 minutes
100%
5 minutes
* Other styles of earphone may differ
Portnuff and Fligor, 2007
Rule of thumb #1
A.K.A. The 80 / 90 principle
At 80% iPod volume
you can listen safely for 90 minutes
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Rule of thumb #2
A.K.A. The arm length principle
If you are listening to your personal music
player and you have to pull out the earphone
to understand someone an arm’s length
away from you, it’s probably too loud.
True or False?
If you can hear the music from someone else’s
headphones, it is at an unsafe volume
False
• Implies that if you hear the music it is hazardous
and conversely if you don’t hear it then it must be
safe.
• When evaluated in both quiet and noisy listening
situations, this screening tool was not predictive of
hazardous sound levels (> 85 dBA).
Weiner, Fligor & Kreisman, 2009
Fligor & Meinke, 2009
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iTunes 6.0.5 or later
and iPod shuffle Software 1.1.4 or later
includes volume limiter software
www.apple.com/sound/
Speaking of
headphones…
which ones are
dangerous?
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noise cancellation
over the ear
earbuds
inserts
www.shure.com
Impact of background noise
limits
A study of 100Recommended
doctoralexposure
students:
70% volume 4.6 hours/day
volume 5 minutes/day
• 6% listened 100%
at dangerous
levels in quiet
• 80% listened at dangerous levels in
background noise
• When using “insert” style, only 20% listened
at dangerous levels
Fligor and Ives, 2007
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Percentage of People Surveyed
“How many hours did you spend listening to
music using headphones with the volume
turned up high over the last two weeks?”
40%
20%
0%
< 2 hours 2 – 5 hours
None
5 – 10
hours
10 - 20
hours
> 20 hours
(Aanchal Sharma, 2009)
Response
Sound Levels experienced while commuting when
listening to iPods/MP3 players
Control
Quiet - 71.7 dBA Leq
Subject
Generic
Song
Favourite
Song
Podcast
Subject
Generic
Song
Favourite
Song
Podcast
1
71.9
76.4
74.6
1
91.3
97
98.3
2
72.7
74.2
72.8
2
81.2
79.4
88.6
3
87.3
90.8
87.6
3
94
100.8
89.6
4
73.6
81.6
78.3
4
86.9
85.8
88.9
5
77.8
91.2
68.2
5
91.5
101.3
86.1
6
82.2
83.3
84.8
6
93.7
93.2
98.3
7
73.1
70.3
72.8
7
93.9
90
90.4
8
69
56.4
71.4
8
91.3
87.7
91.7
9
92.2
91.7
81.3
9
95.6
102.4
94
10
85.1
92.7
82.2
10
94.2
102.5
100.1
11
90.3
86.2
90.4
11
94.3
93.7
94.9
12
95.5
89.3
90.2
12
97.8
93.4
96.9
13
118
116.1
109.5
13
118.9
118.1
116.5
14
95.2
96.2
87.1
14
99.6
102.5
100.2
15
83
76.4
81.2
15
95.5
88.8
98.5
16
89.6
87.5
76
16
94.1
100.2
93.9
For one hour on public transport…
(Laura Scheib, 2009)
Loud – 81.2 dBA Leq
Medium – 77.1 dBA Leq
Subject
Generic
Song
Favourite
Song
Podcast
Subject
Generic
Song
Favourite
Song
Podcast
1
93.4
99.1
100.5
1
98.3
100.2
106.7
2
82.4
89.6
88.9
2
90.4
91.6
91
3
98.8
101.5
95.3
3
100.5
101.4
101.6
4
88.1
86.2
92
4
92.1
91.8
98.8
5
94.2
101.4
87.6
5
97.6
101.2
89.2
6
99
96.4
98.3
6
97.1
98.7
98.9
7
92.3
91.4
92.7
7
96.4
92
96.7
8
88.6
95.4
100.5
8
97
96.4
103.8
9
93.5
106.7
102.3
9
108.3
104
101.8
10
95.5
100.8
107
10
96.6
107.4
108.7
11
99
99.1
102.5
11
96.7
103.6
98.1
12
98.1
100.7
97.8
12
104.3
99.6
97.6
13
119.1
119
116.3
13
119.2
119.4
117.1
14
99.3
101.6
100.4
14
100.2
104.4
101.4
15
99.7
97.8
102.1
15
99.6
99.2
102.1
16
104.3
101.4
102.8
16
108.1
100.9
103.6
For one hour on public transport…
(Laura Scheib, 2009)
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Percentage of people exceeding their
daily dose using their PLD assuming
a 1-hour commute
Environment
Podcast
Generic Song
Control
6%
19%
Favourite Song
13%
Quiet
38%
31%
44%
Moderate
75%
56%
81%
Loud
87%
87%
81%
(Laura Scheib, 2009)
Mean = 87.4
Std. Dev. = 11.9
N = 189
58.2% of PLD users
exceeded daily
sound exposure
limits, and 51.9% of
PLD users exceeded
weekly sound
exposure limits
Thanks to
Jolene!!
Levey, Levey and Fligor, 2011
Meet
Jolene
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Oregonian headline November 20, 2005:
“Headphone users, listen up! (if you still can)”
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Funded by a grant
from the National
Hearing Conservation
Association
V2.3 online now
www.dangerousdecibels.org/jolene.cfm
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