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                               UNITED STATES
                     SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C. 20549

                                SCHEDULE 13G

                 Under the Securities Exchange Act of 1934
                             (Amendment No. 2)*



                            Natus Medical, Inc.
                              (Name of Issuer)


                                Common Stock
                       (Title of Class of Securities)


                                 639050103
                               (CUSIP Number)


                             December 31, 2003
          (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-1(b)
[   ] Rule 13d-1(c)
[   ] Rule 13d-1(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).




     1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
Federated Investors, Inc.


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
      Pennsylvania


Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
5. Sole Voting Power  1,919,600


6. Shared Voting Power

7. Sole Dispositive Power  1,919,600

8. Shared Dispositive Power

9. Aggregate Amount Beneficially Owned by Each Reporting Person  1,919,600

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

11. Percent of Class Represented by Amount in Row (9)  11.64%

12. Type of Reporting Person (See Instructions) HC




     1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).

Voting Shares Irrevocable Trust


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
      Pennsylvania


Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
5. Sole Voting Power  1,919,600


6. Shared Voting Power


7. Sole Dispositive Power  1,919,600


8. Shared Dispositive Power


9. Aggregate Amount Beneficially Owned by Each Reporting Person  1,919,600


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

11. Percent of Class Represented by Amount in Row (9)  11.64%


12. Type of Reporting Person (See Instructions) OO



     1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).

John F. Donahue


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
      United States


Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
5. Sole Voting Power


6. Shared Voting Power  1,919,600


7. Sole Dispositive Power


8. Shared Dispositive Power  1,919,600


9. Aggregate Amount Beneficially Owned by Each Reporting Person  1,919,600


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

11. Percent of Class Represented by Amount in Row (9)  11.64%


12. Type of Reporting Person (See Instructions) IN



     1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).

Rhodora J. Donahue


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
      United States


Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
5. Sole Voting Power


6. Shared Voting Power  1,919,600


7. Sole Dispositive Power


8. Shared Dispositive Power  1,919,600


9. Aggregate Amount Beneficially Owned by Each Reporting Person  1,919,600


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

11. Percent of Class Represented by Amount in Row (9) 11.64%

12. Type of Reporting Person (See Instructions) IN



     1. Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
J. Christopher Donahue


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
      United States


Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
5. Sole Voting Power


6. Shared Voting Power  1,919,600


7. Sole Dispositive Power


8. Shared Dispositive Power  1,919,600


9. Aggregate Amount Beneficially Owned by Each Reporting Person  1,919,600


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

11. Percent of Class Represented by Amount in Row (9) 11.64%


12. Type of Reporting Person (See Instructions) IN


INSTRUCTIONS FOR SCHEDULE 13G

Instructions for Cover Page
(l) 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 13d1(k)(1) 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 14D1) 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.

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-1(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-1(b)(2) and 13d2(c). Statements filed pursuant to
Rule 13d-1(c) shall be filed within the time specified in Rules 13d-1(c),
13d-2(b) and 13d-2(d). Statements filed pursuant to Rule 13d-1(d) shall be
filed not later than February 14 following the calendar year covered by
the statement pursuant to Rules 13d-1(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
Natus Medical, Inc.

(b) Address of Issuer's Principal Executive Offices
1501 Industrial Road, San Carlos, CA 94070

Item 2.

(a) Name of Person Filing SEE ROW 1 OF COVER PAGES


(b) Address of Principal Business Office or, if none, Residence
Federated Investors Tower, Pittsburgh, PA 15222-3779

(c) Citizenship SEE ROWS 1 AND 4 OF COVER PAGES


(d) Title of Class of Securities
Common stock

(e) CUSIP Number 639050103



Item 3. If this statement is filed pursuant to ss.ss.240.13d-1(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) [   ] An investment adviser in accordance with
ss.240.13d-1(b)(1)(ii)(E);

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

 (g) [ X ] A parent holding company or control person in accordance with ss.
240.13d-1(b)(1)(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);

 (j) [   ] Group, in accordance with ss.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.    Federated Investors, Inc. (See Footnote 1, next page)
 (a) Amount beneficially owned: 1,919,600

 (b) Percent of class: 11.64%

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

 (i) Sole power to vote or to direct the vote 1,919,600

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

 (iii) Sole power to dispose or to direct the disposition of 1,919,600

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

B.    Voting Shares Irrevocable Trust
 (a) Amount beneficially owned: 1,919,600

 (b) Percent of class: 11.64%

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

 (i) Sole power to vote or to direct the vote 1,919,600

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

 (iii) Sole power to dispose or to direct the disposition of 1,919,600

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

C.    John F. Donahue
 (a) Amount beneficially owned: 1,919,600

 (b) Percent of class: 11.64%

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

 (i) Sole power to vote or to direct the vote -0-

 (ii) Shared power to vote or to direct the vote 1,919,600

 (iii) Sole power to dispose or to direct the disposition of -0-

 (iv) Shared power to dispose or to direct the disposition of 1,919,600

D.    Rhodora J. Donahue
 (a) Amount beneficially owned: 1,919,600

 (b) Percent of class: 11.64%

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

 (i) Sole power to vote or to direct the vote -0-

 (ii) Shared power to vote or to direct the vote 1,919,600

 (iii) Sole power to dispose or to direct the disposition of -0-

 (iv) Shared power to dispose or to direct the disposition of 1,919,600

E.    J. Christopher Donahue
 (a) Amount beneficially owned: 1,919,600

 (b) Percent of class: 11.64%

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

 (i) Sole power to vote or to direct the vote -0-

 (ii) Shared power to vote or to direct the vote 1,919,600

 (iii) Sole power to dispose or to direct the disposition of -0-

 (iv) Shared power to dispose or to direct the disposition of 1,919,600


Instruction. For computations regarding securities which represent a right
to acquire an underlying security see ss.240.13d3(d)(1).



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.
NOT APPLICABLE

Item 7. Identification and Classification of the Subsidiary Which Acquired
the Security Being Reported on By the Parent Holding Company or Control
Person.
SEE EXHIBIT "1" ATTACHED

Item 8. Identification and Classification of Members of the Group
NOT APPLICABLE


Item 9. Notice of Dissolution of Group
NOT APPLICABLE


Item 10. Certification

 (a) The following certification shall be included if the statement is
filed pursuant to ss.240.13d-1(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 ss.240.13d-1(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.

Date:  February 13, 2004
By: /s/J. Christopher Donahue
Name/Title:  J. Christopher Donahue, as President of Federated Investors,
Inc.

By: /s/John F. Donahue
Name/Title:  John F. Donahue, individually and as Trustee of Voting Shares
Irrevocable Trust, by J. Christopher Donahue, as attorney-in-fact

By: /s/Rhodora J. Donahue
Name/Title:  Rhodora J. Donahue, individually and as Trustee of Voting
Shares
Irrevocable Trust, by J. Christopher Donahue, as attorney-in-fact

By: /s/J. Christopher Donahue
Name/Title:  J. Christopher Donahue, individually and as Trustee of Voting
Shares Irrevocable Trust

Reference is herein made to Exhibit 3, Power of Attorney, filed with the
Securities and Exchange Commission on February 14, 2003.

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 ss.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)

                                EXHIBIT "1"

                          ITEM 3 CLASSIFICATION OF
                             REPORTING PERSONS
            Identity and Classification of Each Reporting Person


IDENTITY                            CLASSIFICATION UNDER ITEM 3

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

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

Federated Investment Management     (e) Investment Adviser registered under
      Company                       section 203 of the Investment Advisers
                                    Act of 1940

Federated Investment Management     (e) Investment Adviser registered under
      Company                       section 203 of the Investment Advisers
                                    Act of 1940

Federated Investment Counseling     (e) Investment Adviser registered
                                    under section 203 of the Investment
                                    Advisers Act of 1940

Federated Global Investment         (e) Investment Adviser registered under
      Management Company            section 203 of the Investment Advisers
                                    Act of 1940
Federated Investors, Inc.           (g) Parent Holding Company, in
                                    accordance with Section
                                    240.13d-1(b)(ii)(G)

FII Holdings, Inc.                  (g) Parent Holding Company, in
                                    accordance with Section
                                    240.13d-1(b)(ii)(G)

Voting Shares Irrevocable Trust     (g) Parent Holding Company, in
                                    accordance with Section
                                    240.13d-1(b)(ii)(G)

John F. Donahue                     (g) Parent Holding Company, in
                                    accordance with Section
                                    240.13d-1(b)(ii)(G)

Rhodora J. Donahue                  (g) Parent Holding Company, in
                                    accordance with Section
                                    240.13d-1(b)(ii)(G)

J. Christopher Donahue              (g) Parent Holding Company, in
                                    accordance with Section
                                    240.13d-1(b)(ii)(G)

Federated Investors, Inc. (the "Parent") is filing this Schedule 13G
because it is the parent holding company of Federated Investment
Management Company, Federated Investment Counseling, and Federated Global
Investment Management Corp. (the "Investment Advisers"), which act as
investment advisers to registered investment companies and separate
accounts that own shares of common stock in Natus Medical, Inc. (the
"Reported Securities').  The Investment Advisers are wholly owned
subsidiaries of FII Holdings, Inc., which is wholly owned subsidiary of
Federated Investors, Inc., the Parent.  All of the Parent's outstanding
voting stock is held in the Voting Shares Irrevocable Trust (the "Trust")
for which John F. Donahue, Rhodora J. Donahue and J. Christopher Donahue
act as trustees (collectively, the "Trustees").  The Trustees have joined
in filing this Schedule 13G because of the collective voting control that
they exercise over the Parent.  In accordance with Rule 13d-4 under the
Securities Act of 1934, as amended, the Parent, the Trust, and each of the
Trustees declare that this statement should not be construed as an
admission that they are the beneficial owners of the Reported Securities,
and the Parent, the Trust, and each of the Trustees expressly disclaim
beneficial ownership of the Reported Securities


                                EXHIBIT "2"

                       AGREEMENT FOR JOINT FILING OF

                                SCHEDULE 13G

      The following parties hereby agree to file jointly the statement on
Schedule 13G to which this Agreement is attached and any amendments
thereto which may be deemed necessary pursuant to Regulation 13D-G under
the Securities Exchange Act of 1934:

      1.   Federated Investors, Inc. as parent holding company of the
investment advisers to registered investment companies that beneficially
own the securities.

Voting Shares Irrevocable Trust, as holder of all the voting shares of
Federated Investors, Inc.

John F. Donahue, individually and as Trustee

Rhodora J. Donahue, individually and as Trustee

J. Christopher Donahue, individually and as Trustee

      It is understood and agreed that each of the parties hereto is
responsible for the timely filing of such statement and any amendments
thereto, and for the completeness and accuracy of the information
concerning such party contained therein, but such party is not responsible
for the completeness or accuracy of information concerning the other
parties unless such party knows or has reason to believe that such
information is incomplete or inaccurate.

      It is understood and agreed that the joint filing of Schedule 13G
shall not be construed as an admission that the reporting persons named
herein constitute a group for purposes of Regulation 13D-G of the
Securities Exchange Act of 1934, nor is a joint venture for purposes of
the Investment Company Act of 1940.

Date:      February 13, 2004

By:   /s/J. Christopher Donahue
Name/Title: J. Christopher Donahue, as President of Federated Investors,
Inc.

By:   /s/ J. Christopher Donahue
Name/Title:     John F. Donahue, individually and as Trustee of Voting
Shares Irrevocable Trust, by J. Christopher Donahue, as attorney-in-fact.

By:   /s/  Rhodora J. Donahue
Name/Title:     Rhodora J. Donahue, individually and as Trustee as Voting
Shares Irrevocable Trust, by J. Christopher Donahue, as attorney-in-fact.

By:   /s/  J. Christopher Donahue
Name/Title:     J. Christopher Donahue, individually and as Trustee of
Voting Shares Irrevocable Trust

1.    The number of shares indicated represent shares beneficially owned by
      registered investment companies and separate accounts advised by
      subsidiaries of Federated Investors, Inc. that have been delegated
      the power to direct investments and power to vote the securities by
      the registered investment companies' board of trustees or directors
      and by the separate accounts' principals.  All of the voting
      securities of Federated Investors, Inc. are held in the Voting Shares
      Irrevocable Trust ("Trust"), the trustees of which are John F.
      Donahue, Rhodora J. Donahue, and J. Christopher Donahue
      ("Trustees').  In accordance with Rule 13d-4 under the 1934 Act, the
      Trust, Trustees, and parent holding company declare that the filing
      of this statement should not be construed as an admission that any of
      the investment advisers, parent holding company, Trust, and Trustees
      are beneficial owners (for the purposes of Sections 13(d) and/or
      13(g) of the Act) of any securities covered by this statement, and
      such advisers, parent holding company, Trust, and Trustees expressly
      disclaim that they are the beneficial owners such securities.