Sound Effects Decibel Level Chart

2017/11/01

I recently purchased some hi-fi earbuds for recreation listening when using my iPhone. While the headphones themselves are great, what I found particularly interesting was a flyer included in the headphones packaging.

The flyer includes a chart that lists the decibel level (dB) of various sound effects. We’ve seen these charts before. This one’s a bit different. I wanted to include this particular chart in a series to consider two important ideas. The first: how does gear affect field recordings you capture?

Sound Clip Decibel Levels

Here’s the chart. I’ve scanned it from the original flyer. Click the image below for a larger version:

That inspired me to make a more detailed chart listing decibel levels for common sound effects. I sourced them from the Web and from Wikipedia:

Sound Type Decibels (dBA) Context
Softest sound possible (at 1 kHz) 0
Rustling leaves Specific 10 Barely audible
Normal breathing Specific 10
Pin dropping Specific 10
Broadcasting studio Ambience 20
Whispering at 5 feet Specific 20
Soft whisper Specific 30 Very quiet
Very calm room Ambience 30
Quiet office or library Ambience 40
Quiet residential area Ambience 40
Babbling brook Specific 40
Computer Specific 40
Moderate rainfall Ambience 50 Quiet
Refrigerator Specific 50
Large office Ambience 50
Light traffic Ambience 50
Electric toothbrush Specific 55
Coffee percolator Specific 55
Normal conversation Specific 60 Intrusive
Sewing machine Specific 60
Television Specific 60
Washing machine Specific 63
Air conditioner Specific 63
Dishwasher Specific 63
Electric shaver Specific 65
Passenger car Specific 70 Difficulty hearing speech
Shower Specific 70
Vacuum cleaner Specific 73
Alarm clock Specific 73
Coffee grinder Specific 75
Hair dryer Specific 78
Power lawn mower Specific 80 Irritating
Toilet flush Specific 80
Pop - up toaster Specific 80
Doorbell Specific 80
Telephone ringing Specific 80
Whistling kettle Specific 80
Food mixer or food processor Specific 85
Blender Specific 85
Hand saw Specific 85
Heavy traffic Ambience 85
Noisy restaurant Ambience 85
Garbage disposal Specific 88
Tractor Specific 90 Very irritating
Truck Specific 90
Electric drill Specific 95
Factory machinery Specific 100 Very loud
Snowmobile Specific 100
Motorcycle Specific 100
Jackhammer Specific 100
Subway Specific 103
Snow blower Specific 105
Baby crying Specific 110 Extremely loud
Power saw Specific 110
Leaf blower Specific 110
Busy video arcade Ambience 110
Car horn Specific 110
Shouting in ear Specific 111
Football game (stadium) Ambience 117
Thunder Specific 120 Painfully loud
Chainsaw Specific 120
Hammer hitting nail Specific 120
Jet taking off (60 metres) Specific 120
Ambulance siren Specific 120
Air raid siren Specific 130
Stock car race Ambience 130
Loudest possible voice Specific 135
Airplane taking off Specific 140
Bicycle horn Specific 143
Jet taking off Specific 150
Artillery fire (500 feet) Specific 150
Fireworks Specific 150
Jet engine Specific 150
Capgun Specific 156
Balloon pop Specific 157
Fireworks Specific 162
Rifle Specific 163
.357 revolver Specific 165
Handgun Specific 166
Shotgun Specific 170
30-06 rifle being fired Specific 171
Howitzer canon Specific 175
Rocket launching (at pad) Specific 180
Sound waves become shock waves 191

You can view it on Google Sheets, or download a copy from the links below:

Not all distances to the subjects were noted, however, most specifics were within 1 meter.

A Guide to Gear Capabilities

Why are these charts interesting?

First, you can use it as a guide for field recording sound effects. We all know that not all recorders and microphones are created equally. Some are designed to shine when paired with certain sound effects, or when doing specific tasks.

That’s why the chart is intriguing: it shows us what is technically required to capture certain sounds. There are many ways to think about this, but I’ll focus on three:

  1. Microphone maximum SPL.
  2. Bit-depth.
  3. Self noise.

1. Maximum SPL

First, not every microphone can capture loud sounds at all. Some may top out at certain decibel ratings and are unable to capture louder sounds. This measurement is known as maximum sound pressure level (SPL). For example, Audio-Technica’s BP4029 stereo shotgun condenser microphone can handle a maximum of 126 dB (click the “Specifications” tab at the link above). That means jet engines and rifle blasts are beyond the capabilities of that microphone.

What happens when attempting to record sounds higher than a microphone’s max SPL rating? The microphone’s diaphragm will be flattened. It just isn’t sensitive enough to capture the powerful waveforms from loud sounds. The result? The sound will be distorted.

What decibel level can your microphone capture? Read a post listing popular microphone statistics to learn more.

2. Bit-Depth

There’s also the idea of bit-depth. Most recorders now provide 24-bit recording. That accommodates for 144.49 dB of signal-to-noise information. What about 16-bit? That tops out at 96.33 dB.

Here’s a chart of other popular bit rates:

Bit Depth Signal-to-Noise Ratio (dB)
8 48.16
16 96.33
20 120.41
24 144.49
32 192.66

How can you improve the dynamic range to capture both quiet and loud sounds? Want the quickest way to expand the number of subjects you can record? Increase your bit depth.

3. Self-Noise

What about quiet sounds? The chart shows us that leaves rustling creeps in at a mere 10 dB. The problem with these sounds isn’t whether or not a microphone can capture 10 decibels. The issue is different: self-noise. This is important when recording soft sounds.

All equipment creates its own noise, referred to as self-noise (or equivalent input noise (EIN)). The very best equipment will create less noise. Less refined gear will introduce more noise into the signal. The result? The noise of the equipment will compete with the quiet sound of the subject.

So, in other words, the list invites us to question how much noise a microphone introduces into a recording. Will this noise be louder than sounds on the list?

Our BP4029 microphone weighs in at 24 dB of self-noise. That means the noise of the equipment will be louder than the rustling leaves (10 dB) it is trying to record. So, considered a certain way, it’s pointless to try to record rustling leaves with this microphone. A recording of a quiet library (40 dB) would be more successful, however the field recording with the BP4029 would still contribute 24 dB of noise to the recording.

Of course, a microphone’s self-noise rating doesn’t tell the whole story of its capabilities. Also, the preamp circuitry’s noise as well as the ambient noise of the location will affect how much noise is in the recording, too. However, considering the noise of the gear and the decibel level of a subject gives field recordists a glimpse into the type of recordings are possible with certain kit.

Decibel Guidelines for Recording

Now, there are other techniques and technologies that allow a field recordist to capture loud sounds typically beyond equipment’s abilities: pads, attenuators, limiters, and so on. There are ways to capture quiet sounds more easily. Also, it’s important to note that specification ratings can be influenced by many factors such as air pressure, frequency, and much more.

However, it’s valuable to look at the raw numbers of subject decibel ratings and equipment stats. Combined, they provide a starting point to learn how the decibel rating of a subject will affect field recording and the equipment used to capture sound fx.

Keep these numbers in mind when choosing gear. A general guideline is that more sophisticated equipment is needed to capture very loud sounds or very quiet ones. Sounds in the middle of our decibel chart are more easily captured. That’s why beginning field recordists find the most success with subjects in the middle of the spectrum. Even the most advanced field recordists struggle to capture sounds at either extreme. But that’s a subject for an upcoming article.

Next: sound effect decibel levels and human hearing.

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