Extension. Get Frequency tone microphone.

[Juan Antonio]

Hello friends,

get frequency tone microphone.

- This extension is similar to SoundAnalysis http://appinventor.mit.edu/extensions/ ... 

- ... but uses a new version of TARSOS library: TARSOS 2.X and a different code.

- This extension is an adaptation of this code: https://0110.be/posts/TarsosDSP_on_Android_-_Audio_Processing_in_Java_on_Android

- To try this extension you can go to this web: Online Tone Generator: http://www.szynalski.com/tone-generator/

- Set a tone and Play, this extension get frequency of that tone.

- With this app you can get level microphone and frequency tone, this app contains two extensions: one to obtain the microphone level and another to obtain the frequency.

- I cann't upload app with extension to this forum, you can get extension: com.KIO4_Frequency.aix and app example p139C_Extension_Microfono_VU3.aia from this web page:

http://kio4.com/appinventor/239D_extensiones_frecuencia_microfono.htm

Regards,

Juan Antonio Villalpando.

[TimAI2]

Looks good Juan :)

Where is the microphone extension ?

[TimAI2]

It is OK, I found it!

Microphone Level Extension

or on your site:

Microphone Level Extension

[Juan Antonio]

Thank you Tim.

With this extension we can get music notes, example from 110 Hz to 196 Hz

[TimAI2]

Cool :)

Does the microphone level equate in any way to decibels ?

[Juan Antonio]

Hi Tim,

We can get level sound in mic from 0 to 32768, but we must calibrate each device (mic) individually.

amplitudeDb = 20 * Math.log10((amplitud) / 32768); 

https://stackoverflow.com/questions/31305163/getmaxamplitude-always-returns-0

also the frequency range depends on each microphone

http://blog.faberacoustical.com/2009/ios/iphone/iphone-microphone-frequency-response-comparison/

[TimAI2]

Is that "ln" or "log" ?  ;)

[EDIT] I see you put log10 in the formula :)

[TimAI2]

The formula is giving me dB in the 0.001 to 0.003 range.

Multiply by 1000 ?

[Juan Antonio]

Hi Tim,

that formula indicates the level of sound with respect to 32768 expressed in decibels, but it is not the typical way to measure a sound.

In this message the author explains quite well certain concepts:

https://stackoverflow.com/questions/10655703/what-does-androids-getmaxamplitude-function-for-the-mediarecorder-actually-gi

To measure the level of sound captured by a mic, dB (spl) is used, this is a pressure measurement referenced to 20 μPa.

http://ec.europa.eu/health/scientific_committees/opinions_layman/en/hearing-loss-personal-music-player-mp3/l-3/2-sound-measurement-decibel.htm

I have modified my extension and added the GetLeveldB block (I prefer to GetLevelDb), this block contains the adapted code that is at the end of:

https://stackoverflow.com/questions/10655703/what-does-androids-getmaxamplitude-function-for-the-mediarecorder-actually-gi

public class NoiseRecorder {...}

You can download extension and example: p139C_Extension_Microfono_VU5.aia from this website:

http://kio4.com/appinventor/239D_extensiones_frecuencia_microfono.htm

Each microphone can be different and must be calibrated with a pattern.

In  Play Store Google:

https://play.google.com/store/search?q=sound+meter&c=apps

[TimAI2]

Many thanks Juan :)