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                                                                                       OMB APPROVAL
                                     UNITED STATES                              ----------------------------
                           SECURITIES AND EXCHANGE COMMISSION                   OMB Number: 3235-0145
                                 WASHINGTON, D.C. 20549                         Expires: December 31, 2005
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                                                                                hours per response........11
                                                                                ----------------------------


                                   SCHEDULE 13G

                   UNDER THE SECURITIES EXCHANGE ACT OF 1934

                               (AMENDMENT NO. 3 )*


                                 Arbitron Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)


                          Common Stock; $.50 par value
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   03875Q108
                             ----------------------
                                 (CUSIP Number)



                                December 31, 2006
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

    [X] Rule 13d-l(b)

    [ ] Rule 13d-l(c)

    [ ] Rule 13d-l(d)

* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).






PERSONS WHO RESPOND TO THE COLLECTION OF INFORMATION CONTAINED IN THIS FORM ARE
NOT REQUIRED TO RESPOND UNLESS THE FORM DISPLAYS A CURRENTLY VALID OMB CONTROL
NUMBER.


                                Page 1 of 6 pages





CUSIP No. 03875Q108
--------------------------------------------------------------------------------

     1.    Names of Reporting Persons.
           I.R.S. Identification Nos. of above persons (entities only).
           H.A. Schupf & Co., LLC 06-1629202
--------------------------------------------------------------------------------
     2.    Check the Appropriate Box if a Member of a Group (See Instructions)

          (a)

          (b)
--------------------------------------------------------------------------------
     3.   SEC Use Only
--------------------------------------------------------------------------------
     4.   Citizenship or Place of Organization   Delaware
--------------------------------------------------------------------------------
 Number of        5. Sole Voting Power  2,361,466
 Shares Bene-     --------------------------------------------------------------
 ficially         6. Shared Voting Power  -0-
 Owned by Each    --------------------------------------------------------------
 Reporting        7. Sole Dispositive Power 2,361,466
 Person With:     --------------------------------------------------------------
                  8. Shared Dispositive Power -0-
--------------------------------------------------------------------------------
     9.  Aggregate Amount Beneficially Owned by Each Reporting Person  2,361,466

     10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares
         (See Instructions)

     11. Percent of Class Represented by Amount in Row (9)  8.0%
--------------------------------------------------------------------------------
     12. Type of Reporting Person (See Instructions)   IA
--------------------------------------------------------------------------------





                                Page 2 of 6 pages




                          INSTRUCTIONS FOR SCHEDULE 13G

INSTRUCTIONS FOR COVER PAGE

(1)  Names and I.R.S. Identification Numbers of Reporting Persons--Furnish the
     full legal name of each person for whom the report is filed--i.e., each
     person required to sign the schedule itself--including each member of a
     group. Do not include the name of a person required to be identified in the
     report but who is not a reporting person. Reporting persons that are
     entities are also requested to furnish their I.R.S. identification numbers,
     although disclosure of such numbers is voluntary, not mandatory (see
     "SPECIAL INSTRUCTIONS FOR COMPLYING WITH SCHEDULE 13G" below).

(2)  If any of the shares beneficially owned by a reporting person are held as a
     member of a group and that membership is expressly affirmed, please check
     row 2(a). If the reporting person disclaims membership in a group or
     describes a relationship with other persons but does not affirm the
     existence of a group, please check row 2(b) [unless it is a joint filing
     pursuant to Rule 13d-l(k)(l) in which case it may not be necessary to check
     row 2(b)].

(3)  The third row is for SEC internal use; please leave blank.

(4)  Citizenship or Place of Organization--Furnish citizenship if the named
     reporting person is a natural person. Otherwise, furnish place of
     organization.

(5)-(9), (11) Aggregate Amount Beneficially Owned By Each Reporting Person,
     Etc.--Rows (5) through (9) inclusive, and (11) are to be completed in
     accordance with the provisions of Item 4 of Schedule 13G. All percentages
     are to be rounded off to the nearest tenth (one place after decimal
     point).

(10) Check if the aggregate amount reported as beneficially owned in row (9)
     does not include shares as to which beneficial ownership is disclaimed
     pursuant to Rule 13d-4 (17 CFR 240.13d-4] under the Securities Exchange
     Act of 1934.

(12) Type of Reporting Person--Please classify each "reporting person"
     according to the following breakdown (see Item 3 of Schedule 13G) and
     place the appropriate symbol on the form:



                    Category                                               Symbol

                                                                        
               Broker Dealer                                                   BD
               Bank                                                            BK
               Insurance Company                                               IC
               Investment Company                                              IV
               Investment Adviser                                              IA
               Employee Benefit Plan, Pension Fund,
                 or Endowment Fund                                             EP
               Parent Holding Company/Control Person                           HC
               Savings Association                                             SA
               Church Plan                                                     CP
               Corporation                                                     CO
               Partnership                                                     PN
               Individual                                                      IN
               Other                                                           OO


Notes:

     Attach as many copies of the second part of the cover page as are needed,
one reporting person per page.

     Filing persons may, in order to avoid unnecessary duplication, answer items
on the schedules (Schedule 13D, 13G or 14D-1) by appropriate cross references to
an item or items on the cover page(s). This approach may only be used where the
cover page item or items provide all the disclosure required by the schedule
item. Moreover, such a use of a cover page item will result in the item becoming
a part of the schedule and accordingly being considered as "filed" for purposes
of Section 18 of the Securities Exchange Act or otherwise subject to the
liabilities of that section of the Act.

     Reporting persons may comply with their cover page filing requirements by
filing either completed copies of the blank forms available from the Commission,
printed or typed facsimiles, or computer printed facsimiles, provided the
documents filed have identical formats to the forms prescribed in the
Commission's regulations and meet existing Securities Exchange Act rules as to
such matters as clarity and size (Securities Exchange Act Rule 12b-12).

              SPECIAL INSTRUCTIONS FOR COMPLYING WITH SCHEDULE 13G

     Under Sections 13(d), 13(g), and 23 of the Securities Exchange Act of 1934
and the rules and regulations thereunder, the Commission is authorized to
solicit the information required to be supplied by this schedule by certain
security holders of certain issuers.

                                Page 3 of 6 pages




     Disclosure of the information specified in this schedule is mandatory,
except for I.R.S. identification numbers, disclosure of which is voluntary. The
information will be used for the primary purpose of determining and disclosing
the holdings of certain beneficial owners of certain equity securities. This
statement will be made a matter of public record. Therefore, any information
given will be available for inspection by any member of the public.

     Because of the public nature of the information, the Commission can use it
for a variety of purposes, including referral to other governmental authorities
or securities self-regulatory organizations for investigatory purposes or in
connection with litigation involving the Federal securities laws or other civil,
criminal or regulatory statutes or provisions. I.R.S. identification numbers, if
furnished, will assist the Commission in identifying security holders and,
therefore, in promptly processing statements of beneficial ownership of
securities.

     Failure to disclose the information requested by this schedule, except for
 I.R.S. identification numbers, may result in civil or criminal action against
 the persons involved for violation of the Federal securities laws and rules
 promulgated thereunder.

                              GENERAL INSTRUCTIONS

A.   Statements filed pursuant to Rule 13d-l(b) containing the information
     required by this schedule shall be filed not later than February 14
     following the calendar year covered by the statement or within the time
     specified in Rules 13d-l(b)(2) and 13d-2(c). Statements filed pursuant to
     Rule 13d-l(c) shall be filed within the time specified in Rules 13d-l(c),
     13d-2(b) and 13d-2(d). Statements filed pursuant to Rule 13d-l(d) shall be
     filed not later than February 14 following the calendar year covered by the
     statement pursuant to Rules 13d-l(d) and 13d-2(b).

B.   Information contained in a form which is required to be filed by rules
     under section 13(f) (15 U.S.C. 78m(f)) for the same calendar year as that
     covered by a statement on this schedule may be incorporated by reference in
     response to any of the items of this schedule. If such information is
     incorporated by reference in this schedule, copies of the relevant pages of
     such form shall be filed as an exhibit to this schedule.

C.   The item numbers and captions of the items shall be included but the text
     of the items is to be omitted. The answers to the items shall be so
     prepared as to indicate clearly the coverage of the items without referring
     to the text of the items. Answer every item. If an item is inapplicable or
     the answer is in the negative, so state.

 ITEM 1.

      (a) Name of Issuer  Arbitron Inc.

      (b) Address of Issuer's Principal Executive Offices  142 West 57th Street,
                                                           New York, NY 10019

 ITEM 2.

      (a) Name of Person Filing   H.A. Schupf & Co., LLC

      (b) Address of Principal Business Office or,
          if none, Residence                                 590 Madison Avenue,
                                                              New York, NY 10022
      (c) Citizenship  Delaware

      (d) Title of Class of Securities   Common stock; $.50 par value

      (e) CUSIP Number  03875Q108

ITEM 3. IF THIS STATEMENT IS FILED PURSUANT TO SECTIONS 240.13D-L(b) OR
240.13D-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A:

      (a) [ ]  Broker or dealer registered under section 15 of the Act (15
               U.S.C. 78o).

      (b) [ ]  Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

      (c) [ ]  Insurance company as defined in section 3(a)(19) of the Act (15
               U.S.C. 78c).

      (d) [ ]  Investment company registered under section 8 of the Investment
               Company Act of 1940 (15 U.S.C 80a-8).

      (e) [X]  An investment adviser in accordance with Section 240.13d-1
               (b)(1)(ii)(E);

      (f) [ ]  An employee benefit plan or endowment fund in accordance with
               Section 240.13d-1 (b)(1)(ii)(F);

      (g) [ ]  A parent holding company or control person in accordance with
               Section 240.13d-l(b)(l)(ii)(G);

      (h) [ ]  A savings associations as defined in Section 3(b) of the Federal
               Deposit Insurance Act (12 U.S.C. 1813);

      (i) [ ]  A church plan that is excluded from the definition of an
               investment company under section 3(c)(14) of the Investment
               Company Act of 1940 (15 U.S.C. 80a-3);


                               Page 4 of 6 pages





      (j) [ ]  Group, in accordance with Section 240.13d-1(b)(1)(II)(J).

 ITEM 4.   OWNERSHIP.

     Provide the following information regarding the aggregate number and
percentage of the class of securities of the issuer identified in Item 1.

      (a) Amount beneficially owned: 2,361,466.

      (b) Percent of class: 8.0%.

      (c) Number of shares as to which the person has:

          (i)   Sole power to vote or to direct the vote 2,361,466.

          (ii)  Shared power to vote or to direct the vote -0-.

          (iii) Sole power to dispose or to direct the disposition of 2,361,466.

          (iv) Shared power to dispose or to direct the disposition of -0-.

     Instruction. For computations regarding securities which represent a right
     to acquire an underlying security see Section 240.13d-3(d)(l).

ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

     If this statement is being filed to report the fact that as of the date
hereof the reporting person has ceased to be the beneficial owner of more than
five percent of the class of securities, check the following [].

Instruction: Dissolution of a group requires a response to this item.

ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

     If any other person is known to have the right to receive or the power to
direct the receipt of dividends from, or the proceeds from the sale of, such
securities, a statement to that effect should be included in response to this
item and, if such interest relates to more than five percent of the class, such
person should be identified. A listing of the shareholders of an investment
company registered under the Investment Company Act of 1940 or the beneficiaries
of employee benefit plan, pension fund or endowment fund is not required.

ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE
SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY

     If a parent holding company has filed this schedule, pursuant to Rule
13d-l(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the
identity and the Item 3 classification of the relevant subsidiary. If a parent
holding company has filed this schedule pursuant to Rule 13d-l(c) or Rule
13d-l(d), attach an exhibit stating the identification of the relevant
subsidiary.

ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP

     If a group has filed this schedule pursuant to Section
240.13d-l(b)(l)(ii)(J), so indicate under Item 3(j) and attach an exhibit
stating the identity and Item 3 classification of each member of the group. If a
group has filed this schedule pursuant to Section 240.13d-l(c) or Section
240.13d-l(d), attach an exhibit stating the identity of each member of the
group.

ITEM 9. NOTICE OF DISSOLUTION OF GROUP

     Notice of dissolution of a group may be furnished as an exhibit stating the
date of the dissolution and that all further filings with respect to
transactions in the security reported on will be filed, if required, by members
of the group, in their individual capacity. See Item 5.

ITEM 10. CERTIFICATION



                                Page 5 of 6 pages




     (a)  The following certification shall be included if the statement is
          filed pursuant to Section 240.13d-l(b):

               By signing below I certify that, to the best of my knowledge and
               belief, the securities referred to above were acquired and are
               held in the ordinary course of business and were not acquired and
               are not held for the purpose of or with the effect of changing or
               influencing the control of the issuer of the securities and were
               not acquired and are not held in connection with or as a
               participant in any transaction having that purpose or effect.

     (b)  The following certification shall be included if the statement is
          filed pursuant to Section 240.13d-l(c):

               By signing below I certify that, to the best of my knowledge and
               belief, the securities referred to above were not acquired and
               are not held for the purpose of or with the effect of changing or
               influencing the control of the issuer of the securities and were
               not acquired and are not held in connection with or as a
               participant in any transaction having that purpose or effect.

                                    SIGNATURE

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

                                               January 29, 2007
                                               ---------------------------------
                                                            Date


                                               /s/ H. Axel Schupf
                                               ---------------------------------
                                                          Signature


                                               H. Axel Schupf, Managing Member
                                               ---------------------------------
                                                          Name/Title


     The original statement shall be signed by each person on whose behalf the
 statement is filed or his authorized representative. If the statement is signed
 on behalf of a person by his authorized representative other than an executive
 officer or general partner of the filing person, evidence of the
 representative's authority to sign on behalf of such person shall be filed with
 the statement, provided, however, that a power of attorney for this purpose
 which is already on file with the Commission may be incorporated by reference.
 The name and any title of each person who signs the statement shall be typed or
 printed beneath his signature.

 NOTE: Schedules filed in paper format shall include a signed original and five
 copies of the schedule, including all exhibits. See Section 240.13d-7 for other
 parties for whom copies are to be sent.

ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSIONS OF FACT CONSTITUTE FEDERAL
CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001)





                                Page 6 of 6 pages