AutoVolume (AV) is a fine-tunable system that automatically adjusts the volume output of your headphone (music volume) by measuring and averaging ambient noise levels around you with the microphone (outside noise).

Introduction

Use AV while traveling on transport, walking on loud streets, or sitting in the office where sudden attention is needed.

Since this app is about controlling volume level for your ears, you need to understand, set up, save and do some experiments on your own before using AV.

Usually using AV means launching the app, start music if it's not already playing and choosing the right profile for the environment.

Use different profiles in different situations. Situations like traveling on bus or sitting in office (you can edit and save profiles in Full version only).

Everything can run in the background.

Don't forget to turn off AV when not using.

AV supports two mode for adjusting the music volume:

In Amplifier Mode volume adapts to the outside noise and in Office Mode volume drops to the outside noise.

Set up min and max volume limits depending to the AV Mode (Amplifier or Office).

In Amplifier mode: Set the minimum limit to the level that you find appropriate in a silent environment (like your room). Then set the maximum limit to the level that you find appropriate in a very noisy environment.

AV is a fine-tunable system. That means you can configure just about everything!

Change in/out volume characteristics, use different averaging methods, change volume fader speed, change sampling speed and length and many more (in full version app).

For further reading about the AV parameters go to the Help section or shake the device for visual help assistance.

Visit www.autovolumeapp.com for support and some brainstorming about what should be included in the next version of AutoVolume.

Put your headphones on, start music playing and do some experiments about how AV reacts to noise.

And remember that in most cases with Amplifier mode you do not want sudden and one-off noises to raise volume, like door shutting sound.

"Averaging the right amount of time with the right frequency is the key for good volume control."

If the averaging period is too long then AV will react slow, if too short then on-off noises will make the volume raise.

You will need to be wearing your headphones with integrated microphone to enjoy this product.

AutoVolume is compatible with iPhone and iPod touch. It requires iPhone OS 3.0 or later.

• You can switch to the Menu and back to the built-in iPod player by pressing the AutoVolume logo located on the top of the screen.

• Music playback can be started and controlled by the native iPod app or simultaneously by the built-in player that has access to your iPod library. The result will be the same. Just add playlists, albums to the player after pressing button.

• Pre-configured profiles are available for different situations. You can always load the correct one, save changes, or create your own profile out of preset one. Manage them at Menu->Profile

• Always remember to turn AV off when not using by pressing off button or closing it. Otherwise it is sampling outside noise levels for nothing.

• AV can do it's magic in the background if your iphone supports this function. If not then just lock the iPhone while using AV.

• Flashing red status bar will always inform you that AV is turned on and sampling. (sampling = measuring outside noise level at the speed of Samples per Minute)

• You can only use AV with headphone that has a built-in microphone. Every iPhone is shipped with one.

• Profiles are saved at every exit (if the loaded profile is read-only changes will be saved to "Unsaved" profile)

• Phone call interruptions are managed. AV will continue just along with the music.

AV supports two mode for adjusting the music volume.

In Amplifier Mode volume adapts to the outside noise and in Office Mode volume drops to the noise outside

Set up min and max volume limits depending to the AV Mode (Amplifier or Office).

In Amplifier mode:

• Set the minimum limit to the level that you find appropriate in a silent environment (like your room).

• Then set the maximum limit to the level that you find appropriate in a very noisy environment.

AV samples the ambient noise level at the speed of given Samples per Minute. A Number of Samples builds up one measuring cycle. When one cycle is complete AV will calculate the average or choose the median volume value of the samples.

This value is then passed to the characteristic function, the corresponding output level triggers min-max volume correction if passes the threshold.

If the fader is turned on then there will be some delay while reaching the freshly calculated output level. You can see this effect on the characteristics curve chart.

Also you don't want to over sample. Average is the goal. It's also a big factor on battery saving!

Quick Noise

It's an Amplifier too but the noise sampling process is short and not making any average out of it. Sampling duration (Total duration) is 0.4 seconds long. AV will constantly change the volume (if threshold check passes).

The "slow" volume fader does the volume regulating job! It is always fading somewhere.

• The noise input has to be constant enough to make volume fade in to the desired volume level. Otherwise volume will start to fade back.

Advantages:

• quick, more frequent reaction on volume change
• makes it easy to customize reaction speed with the Fader Speed slider

Disadvantages:

• short period, on-off noise makes a slight volume change (meanwhile the fader will start to regulate itself back in 0.4 seconds)
• not capable to determine the average noise environment

Constant noise

It's an Amplifier! Most suitable for traveling on transport or being in the city where outside noise is constantly changing. Like raveling on noisy transport that is making stops, passing by loud streets.

This profile does some averaging and excludes short period, on-off noises! Only constant noise matters.

• What on-off noises to exclude? door shutting sound, sneezing, dropping a pen on the floor

• If you wish AV not to take any effect on these type of noises then it's a choice for you. But you have to give up on the reaction speed.

Sampling duration (Total duration) is 3.0 seconds long.. 8 samples is taken by that time.

Average is determined by using median. This profile uses the 3rd index as the median (not 4th as the middle one should be).

• That means the 3rd highest volume level out of the 8 samples will be the average noise level.

• Developer's view is that this is the best configuration to exclude on-off noises but keeping the reaction speed fast enough.

Advantages:

• excludes short period, on-off noises by using median averaging
• determines average volume of the environment

Disadvantages:

• slow reaction on volume change
• not so precise on average, because of excluding on-off noises

Average noise

An Amplifier that has a slow fader and reaction speed but calculates a precise average of the environment.

Sampling duration (Total duration) is 3.8 seconds long and Fader speed is only 0.59

Advantages:

• precise average
• determines average volume of the environment

Disadvantages:

• short period, on-off noise does a slight volume change (meanwhile the fader will start to regulate itself back in 3.8 seconds)
• slow reaction speed

Office

It's a Limiter! Perfect choice for sitting in the Office and working on something (keyboard noise, etc.) If someone calls your name or you start talking then the volume will quickly reduce itself and hold it that way for 5 seconds (Hold at Minimum function).

The characteristic function makes a minimum input threshold for 0.28. Noises below this volume will not have any effect on the output volume. Noises above 0.28 will trigger the Hold at Minimum function.

• You can change this threshold on the characteristic curve be moving it to the left or right.

Fader is on but it's fast.

Awareness

Same as Office profile, but the input threshold is lower (using the characteristic function).

Any tiny noise higher then 0.8 will trigger Hold at Minimum function for 5 seconds.

Quick Limiter

Quickly limits the volume when talking. It will increase volume back as soon you stop talking.

DJ's use this when talking on radio.

Hold at Minimum is only 1 seconds long.

• You can change the volume with the volume control side buttons on the device.

• In Amplifier mode it will change the minimum volume. In Office mode it will change the maximum volume limit.

Shifting the max limits:

• If you feel that AV is is not loud enough while the volume is hitting the maximum limit, then pressing volume up button will shift the maximum limit up.

Volume fader in action (AutoVolume is changing the volume)

AutoVolume is thresholding (no relevant noise amount change)

Volume has reached the minimum or maximum output level

Holding the volume at low for a pre-configured number of seconds

• Creating a new profile after settings being made: Goto Menu -> Profiles -> New

• AutoVolume has a couple of read-only, pre-configured profiles that can be used for a start. (It's still recommended to save your own custom one)

• Profile names with dark black text color are read-only.

• Profiles are saved at every application exit (or when switching app to background).

• If the loaded profile is read-only changes will be saved to Unsaved profile.

• Otherwise, your custom made profiles (that are not read-only) are saved automatically.

• Deleting, saving a read-only profile is not allowed.

• Naturally, AV drains the battery faster then just listening to your ipod. However measuring the outside noise levels doesn't mean that AV is recording the whole time. AV just takes a little sample every second or so (frequency can be adjusted). Average of the samples is the important information for AV. This sampling process drains the battery at a very slow pace that allow you to use it the whole day.

• AutoVolume's CPU load is only 5% by average.

Set up minimum and maximum volume limits depending to the AV Mode (Amplifier or Office).

In Amplifier mode:

• Set the minimum limit to the level that you find appropriate in a silent environment (like your room).

• Then set the maximum limit to the level that you find appropriate in a very noisy environment.

• You can check or change different input and output level characteristics on the curve chart.

• To change the curve you have to touch + hold and then move the control points displayed on the chart, one at a time.
  
  

• Characteristics can be also used as threshold.

• AV will change the output level only when the input change is bigger then the threshold.

• The main goal is to lower the number of output changes and calculations.

• Insignificant input changes only drain the battery faster and will confront you with a notification of volume change in case AV is backgrounding. (Sorry, almost nothing can be done against this notification)

• Range from 0.00 to 1.00 in [volume level]

• Recommended settings are 0.02 - 0.05 in Amplifier Mode and 0.1 – 0.3 in Office Mode

More Info:

• In case of 0.00 the output level will be always calculated to a new level. No matter how small the input change is since the last calculation

• In case of Office Mode it makes sense setting the threshold at a high level. This way AV will only react to high input change.

• Don't set the threshold level to high in Amplifier Mode. Big threshold can cause imprecise output levels.

• In some cases threshold can be overwritten with the help of the characteristics curve chart.

• AV will keep skipping threshold check at every given number of sampling cycles.

• A Number of Samples builds up one measuring cycle.

• The main goal with this parameter is to let AV re-regulate itself after a number of sampling cycles, incase the threshold is to high.

• New volume level can fade in and out gracefully or it can just simply jump to the new volume level after the calculation.

• Jumping to the new volume level makes sense in Office Mode. If you wish AV to silence the output level immediately and not gracefully.

• In case of Amplifier Mode it’s much pleasurable to have the fader turned on.

• Fader has a volume regulating effect. Noise has to be constant to make the fader reach it's goal.

• Fader Incrementation is the pace of volume increase.

• The higher the Fader Speed the faster the pace of the fader following the new output volume.

• Set the right Incrementation value for your AV Mode and then alter the fader speed that suits your needs.

• These parameters could have a big impact on AV's reaction speed against new input changes.

• In some cases the fader can change to different direction before reaching the last calculated new output volume level. That means calculation is faster then the fader reaching the goal level.

• You can still use the fader in Office Mode. However make sure fader is quick enough to alert you! Or just simply turn it off.

• Works only in Office Mode

• If actual output level reaches the value of minimum volume limit then it will hold the output volume at that position for a pre-configured number of seconds.

• This way you will have a period of time to listen and look for what is going on around you while the volume remains low.

• With the Hold at Minimum process AV will stop measuring

• In case of median averaging mode AV will sort the input samples increasingly and choose the middle sample in line, this will be the median. Output level will be compared with the median using the Characteristics function.
  

• This average mode is very handy when it comes to excluding short period sounds.In most cases with Amplifier Mode you don’t want sudden and one-off noises to raise volume, like door shutting noise. If that door shutting noise is not frequent enough it will be left out of the median average.

  Example of sampling to two short sounds (irrelevant noise)
  
  
  With simple average the short sounds does have inpact on the average
  
  
  With median average the short sounds are excluded
  

• In average mode a short and loud sound will have it's effect on the the average and later in the volume.

• Everything has a price. Due to median mode there are some random delays where average mode would react much faster.

  Noise being sampled
  
  
  If the noise is not costant (smaller then half of the sampling durration) then it will get excluded.
  

• In case of Office mode you may want AV to react on any unexpected noise. So you should make an average in a short period of time.

This value in seconds depends on the Number of Samples and the Samples per Minute.

Usually in Amplifier Mode it's better to take more Number of Samples since we don't want AV to take average from short sounds like a single clap. Averaging 5-10 seconds makes sense if we are sitting on transport that stops and goes.

• With MicTouch Protection there will be no false noise samples caused by clicking the microphone with your fingers.
  

• Protection is active if AV is running in the background or the iphone is locked.

• Setting on is recommended.

More Info:

• In active mode, every user made button click on the microphone will clear the measured samples and start sampling in a few seconds again. (Due to technical limitations the iphone volume side buttons will do the same effect)

• Your last click will be always the beginning of a new sampling cycle.

• Setting on is recommended since you will probably use the iPod controls located on the microphone.

Once you purchase an application, you can download updated versions without any additional charge. Please download new release through the App Store on iPhone or the iTunes Store on your computer: http://www.apple.com/iphone/how-to/#app-store.updating-applications

Please backup all your data before installing the new version. Import your records and settings after successful installation of new version.

If you accidentally deleted a purchased application before you got a chance to back, just follow the simple instructions to re-download your App Store purchase: http://support.apple.com/kb/HT2519