Practical Explanation and Common Questions Answered
Q: What is it?
A: Loud Enough is an in-ear, diaphragm-based, sound isolating headset that is intended for use by children by parents who wish to limit the volumes their kids are exposed to.
Q: Who is it for?
A: Loud Enough was designed for kids, but it is ideal for all ages, 6 and over. It is a must have for those listeners who want top quality sound, but are also concerned about their hearing protection. Loud Enough earphones are also the perfect gift for all those "kids" in your life.
Q: What does it do?
A: Loud Enough does two things. First, because the headset is designed for children, physical attributes allow for a much better seal. Seal is the most critical ingredient in delivering a high quality listening experience. The improved seal reduces the level of volume required to get a high quality, accurate sound. Second, because the headset has reduced sensitivity relative to non-level reducing headsets, it has a reduced maximum sound pressure level (SPL) that can be reached when driven by a music player.
Q: How does Loud Enough Reduce SPL?
A: A typically headset consists of a small speaker that is driven directly by the music player (iPod, etc). Loud Enough limits the amount of power delivered to the speaker by inserting an energy dissipating device before the speaker. Instead of ll the power from the music player going to the speaker, a designated percentage of the power is dissipated prior to reaching the speaker. As power to the speaker is reduced, so is the sound pressure, or, sound pressure level that reaches the user.
Q: How much does Loud Enough Reduce SPL?
A: When tested against comparable non-reducing, noise isolating headsets (using the same music player and output level) Loud Enough reduces maximum SPL by approximately 20dB. This reduction is heard as about 25% the loudness.
When tested against the popular iPod ear buds (that Apple includes with their iPods) the reduction is less since iPod ear buds transfer less pressure to the eardrum due to their non-isolating design. This shows a reduction of 12dB which will be perceived as approximately 50% the loudness.
Examples using iPod ear buds and A-Weighted SPL values in dB...
| Song at Max iPod volume | iPod Ear buds | Loud Enough |
|---|---|---|
| My Humps (Black Eyed Peas) | 101.1 | 89.7 |
| This Love (Maroon 5) | 107.3 | 95.7 |
| New Kid In Town (Eagles) | 88.3 | 76.3 |
Q: What does this mean in terms of listening time?
A: The accepted standards for recommended permissible exposure time for continuous time weighted average noise are as follows:
| Continuous dB | Permissible Exposure Time* |
|---|---|
| 85dB | 8 Hours |
| 88dB | 4 Hours |
| 91dB | 2 Hours |
| 94dB | 1 Hour |
| 97dB | 30 Minutes |
| 100dB | 15 Minutes |
| 103dB | 7.5 Minutes |
| 106dB | <4 Minutes |
| 109dB | <2 Minutes |
*According to NIOSH (National Institute of Occupational Safety and Health) and CDC (Center for Disease Control) guidelines issued in 2002.
We designed our LE products to provide parents with some degree of confidence that their children could listen for a minimum of 1 Hour at maximum sound output and with some oversight, a few hours.
Q: What is Sound Pressure Level, SPL?
A: SPL numbers are a way of describing the relative level of a sound compared to the lowest possible sound a human can hear. The lowest physical sound pressure detectable by humans is 0.00002 pascal (Pa) and that equates to 0dB SPL.
To Calculate SPL in dB: dB SPL = 20*LOG (Sound Pressure/reference pressure, or, 0.00002)
So, for a person sitting 3 feet from a television set, the sound pressure is 0.02Pa. The corresponding SPL in dB is:
SPL = 20*LOG (0.02/0.00002) = 60dB
Put into the real world, SPL levels that you might associate with are as follows:
| Event | Approximate dB Level |
|---|---|
| Normal Conversation | 60dB |
| Busy NY Street | 70dB |
| City Traffic | 85dB |
| Truck Traffic | 90dB |
| Subway Train | 95dB |
| Power Mower | 107dB |
| Night Club | 115dB |
| Rock Concert | 120dB |
| Death of hearing tissue at 180dB | |