Skip to content Skip to navigation Skip to collection information

OpenStax-CNX

You are here: Home » Content » ELEC 301 Projects Fall 2006 » Decoding Frequencies into Notes

Navigation

Table of Contents

Lenses

What is a lens?

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

This content is ...

Affiliated with (What does "Affiliated with" mean?)

This content is either by members of the organizations listed or about topics related to the organizations listed. Click each link to see a list of all content affiliated with the organization.
  • Rice University ELEC 301 Projects

    This collection is included inLens: Rice University ELEC 301 Project Lens
    By: Rice University ELEC 301

    Click the "Rice University ELEC 301 Projects" link to see all content affiliated with them.

  • Rice Digital Scholarship

    This collection is included in aLens by: Digital Scholarship at Rice University

    Click the "Rice Digital Scholarship" link to see all content affiliated with them.

Also in these lenses

  • Lens for Engineering

    This collection is included inLens: Lens for Engineering
    By: Sidney Burrus

    Click the "Lens for Engineering" link to see all content selected in this lens.

Recently Viewed

This feature requires Javascript to be enabled.
 

Decoding Frequencies into Notes

Module by: Alan Gostin. E-mail the author

Summary: This module discusses the method to convert a given frequency to the note that was most likely played to generate it.

Now that the frequencies in each window have been found, it is time to determine what note was most likely played to generate each frequency. As we know that each frequency is 2 12 12 2 times larger than the preceding frequency, we can declare the points that are 2 24 24 2 times larger and smaller than the known note frequency to be the limits of the range of frequencies that map to that known note. Thus for a known frequency, fofo, the range of frequencies that map to it is:

2 -24 *fof< 2 24 *fo -24 2 *fo f 24 2 *fo
(1)

If we do this for every known note frequency, then the limits for two adjacent frequency ranges coincide exactly, and we have a function that maps any frequency to a note. Such a function is graphed below.

Figure 1: A section of the regression curve used spanning from 440 Hz to 1760 Hz. Shown in more detail is the range of frequencies that correspond to A#5.
Figure 1 (noteDecoding50.png)

This is the regression curve we used to map frequencies to notes. A fast way of implementing it is to number each note from 1 to 88, starting with the lowest note that can be played with a piano, and ending at the highest. After doing this, the following Matlab expression will evaluate this curve:

round(12*log(f/27.5)/log(2))+1

Collection Navigation

Content actions

Download:

Collection as:

PDF | EPUB (?)

What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Module as:

PDF | More downloads ...

Add:

Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks