Understanding Noise Levels (in Headphones)

Your Guide to Understanding Noise Levels

Did you know that each headphone you own has a different sound?  It is true.  In fact, you can hear the difference by testing them out side-by-side.  Therefore we make sound comparisons between headphones and graph various sounds to help you with understanding noise levels.

Understanding Sound Ratings

Loud noise can be disruptive to the hearing and affects business. Exposure to loud noise can cause hearing impairment and affect emotional well-being. Employers may be subject to liability. Even at low levels, unwanted noise can have a devastating effect on productivity and morale.

Two basic categories are the best for solving the many noise problems and challenges. Sound management techniques have been developed using sound-acoustics science. They are adapted to the specific noise problem.

  • Absorption is the process by which sound energy is removed from a space. This is typically done with porous, soft materials to absorb sound.
  • Transmission is the movement or transmission of sound through a medium. It is necessary to use specialized products and techniques to prevent the transmission of sound through door openings.

It is important to have a basic understanding of the two types of noise that you want and the acceptable level. The difference between these two values determines the level of sound control you should achieve when your door is opened.

Sound is the result of vibrations in air moving in waves. Frequency (also known as hertz or Hz) is the rate of sound pulsations measured per second.

Sound pressure levels are measured as decibels, or dB. dB is the scale used to simulate sound across the frequency range. Even slight changes in these levels can have a significant impact on the way the human ear perceives loudness. A 3dB increase will double the sound reception as well as the discomfort and annoyance that it causes.

Some of the energy that is transferred to the door by sound when it contacts a barrier such as a door or other object, like sound, is transferred to the door. The door vibrates, creating sound vibrations on the other side, then transmits the energy to the air.

Sound waves are impeded by the barriers mass, damping, and stiffness. The barrier will transmit less sound if it is heavier. Mass is crucial for blocking lower frequency sounds. MDF due to its density and weight is a great sound barrier. TruStile MDF Doors provide excellent sound barrier properties.

Comparative Examples of Noise Levels

 

Noise Source Decibel Level Decibel Effect
Take-off by jet (at 25 m)
Recommended product
150 Fragmentation of Eardrum
Aircraft carrier deck 140
Take-off of military jet aircraft from aircraft carrier at 50 feet (130dB). 130
Thunderclap and chain saw. Oxygen torch (121 dB). 120 Painful. 32 times as loud and as high as 70 dB
Steel mill, autohorn at one meter. Turbo-fan aircraft at takeoff speed at 200 feet (118 dB). Riveting machine (110 dB); live rock music (108 – 114 dB). 110 Average human pain threshold. 16 times as loud than 70 dB
Jet takeoff (at 305m), use of an outboard motor or power lawn mower, motorcycles, tractor, jackhammer, and garbage truck. Boeing 707 or DC-8 aircraft one nautical mile before landing (106dB); jet flyover 1000 feet (103dB); Bell J-2A helicopter at 100ft (100dB). 100 8 times louder than 70 dB. Serious damage possible in 8 hr exposure.
Boeing 737 or DC-9 aircraft one nautical mile before landing (97 dB); motorbike at 25 ft (96) dB; power mower (96 dB); bike at 25 ft (90 dB). Newspaper press (97dB). 90 It is 4 times as loud at 70 dB. Potential damage after 8 hours of exposure
Garbage disposal and dishwasher; average factory; freight train (at 15 m). Car wash at 20 ft. (89.DB); propeller plane flyover over 1000 ft. (88 DB); diesel truck 40 MPH at 50 Ft. (84 DB); diesel train 45 MPH at 100 Ft. (83 dB). Food blender (88 dB); milling machine (85 dB); garbage disposal (80 dB). 80 It is 2x louder than 70 decibels Potential damage after 8 hours exposure
Passenger car travelling at 65 mph (25 ft) (77dB); freeway traveling 50 ft away from the pavement edge, 10 a.m. (10 dB). Living room music (76 DB); radio or TV-audio; vacuum cleaner (70 DB). 70 Base arbitrarily used for comparison. The upper 70s can be annoyingly loud for some people.
Conversation in restaurant or office with background music. 60 Only half as loud as 70dB Fairly quiet.
A quiet suburb with plenty of conversation. Electrical transformers up to 100 feet. 50 One-fourth the volume of 70 dB.
Library, bird callings (44 dB); low limit urban ambient sound 40 One-eighth as loud at 70 dB.
It is a peaceful rural area. 30 It’s only 1/6th as loud at 70 dB. Very quiet
Whisper, rustling of leaves 20
Breathing 10 Barely audible

Important disclaimer:

Many headphones won’t sound the same as the ones in any comparison videos. This is because the sound quality of the video will be different from what you hear on your phone, your laptop, or your PC speakers.

Your listening quality may not be 100% accurate. Therefore, the actual sound signature might sound slightly different.  We believe it is a better representation of sound quality that simply putting words to it.

Although you’re welcome and encouraged to use comparisons to help make better buying decisions, keep in mind the limitations.

Noise Levels: FAQs

How do you understand sound comparisons?

The original track is neutral.  Comparing the original track and the recorded headphones will show you the differences. This will give you an idea of the headphones you need.

How to understand sound comparisons?

Listening to non-neutral headphones can influence your opinion.  If you are using headphones that are heavily colored, your hearing will be different from the one we have. All audio tracks are mixed and mastered with neutral-sounding equipment. This represents a reference point.

Let’s suppose that the headphones being tested have a bass boost. You can also listen to our comparison using headphones. Our recording was remastered to sound exactly like the headphones we tested, so we have increased lower frequencies.

When you compare our recording with your headphones and a bassy headset, the comparison will sound extremely bass-forward. To get a true picture of the sound quality of our headphones, you will need to listen to them yourself.

Equipment Used to make Sound Comparisons?

  • MiniDSP H.E.A.R.S.

These artificial ears are equipped with microphones at both ends of the ear canals. They are able to simulate the human head by using molded earlobes (or pinna). It is important to note that these are not an industry standard. A whole torso can be purchased with a head for $10.000 and more. However, H.E.A.R.S. The H.E.A.R.S. still offers a great insight into headphones’ sound quality.

  • Neutral Headphones

Sennheiser HD 6XXX and Ollo audio S4 can be used to adjust our sound recordings.

They are extremely well-balanced headphones that are often used in studios. These headphones are an excellent choice to correct the frequency response in audio recordings.

  • Audacity

It’s a free software that offers many useful tools for recording and editing audio recordings. Audacity can be used to record and tweak frequency response later.

Audacity can’t make real-time EQ adjustments, so we use AIMP 3 music and its built in EQ.

What is the best way to record sound?

First, we attach headphones to our MiniDSP H.E.A.R.S. Over-ears that are larger don’t need as much adjustment. For best results, we must change the ear tips on our earbuds. We tend to use the smallest.

This is the point where we create a new Audacity project, start recording again and play a pre-selected track that’s in all our comparisons.

We also guarantee a quiet environment for testing, as sensitive microphones can detect any movement or ambient noise.

We stop recording after the song ends. The audio recording is saved in the best quality (MP3 -320kbps).

  • How can we make comparisons?
  • The recording sounds dull, but it’s not like the headphones that we’re using.
  • We must correct the recording and adjust its frequency response before publishing the final comparison.

Since they don’t color the sound, neutral headphones are a good reference. Neutral headphones are a great reference because they assure us that the recordings will not sound completely different in final sound comparisons.

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