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

                                  SCHEDULE 13D
                    Under the Securities Exchange Act of 1934
                               (Amendment No. 10)

                       NATUS MEDICAL INCORPORATION (BABY)
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                                (Name of Issuer)

                                  Common Stock
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                         (Title of Class of Securities)

                                    639050103
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                                 (CUSIP Number)

                                David Nierenberg
                               The D3 Family Funds
                               19605 NE 8th Street
                                 Camas, WA 98607
                                 (360) 604-8600

                                 With a copy to:

                               Henry Lesser, Esq.
                                DLA Piper US LLP
                             2000 University Avenue
                            East Palo Alto, CA 94303
                                 (650) 833-2000

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                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                   May 9, 2007
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             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D and is filing this
schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check
the following box(TM).



--------------------------------------------------------------------------------
1    NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

     The D3 Family Fund, L.P.
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2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
     (See Instructions)
                                                                 (a)  [X]
                                                                 (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY

--------------------------------------------------------------------------------
4    SOURCE OF FUNDS (See Instructions)

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) or 2(e)                                   [ ]

--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     Washington
--------------------------------------------------------------------------------
  NUMBER OF    7    SOLE VOTING POWER
   SHARES
BENEFICIALLY        702,291 Common shares (3.3%)
  OWNED BY     -----------------------------------------------------------------
    EACH       8    SHARED VOTING POWER
 REPORTING
   PERSON           0
    WITH       -----------------------------------------------------------------
               9    SOLE DISPOSITIVE POWER

                    702,291
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    0
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     For the reporting person listed on this page, 702,291; for
     all reporting persons as a group, 4,083,914 shares (18.9%)
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES (See Instructions)

     (TM)
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     18.9%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON (See Instructions)

     PN
--------------------------------------------------------------------------------

                                        2



--------------------------------------------------------------------------------
1    NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

     The DIII Offshore Fund, L.P.
--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
     (See Instructions)
                                                                 (a)  [X]
                                                                 (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY

--------------------------------------------------------------------------------
4    SOURCE OF FUNDS (See Instructions)

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) or 2(e)                                   [ ]

--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     Bahamas
--------------------------------------------------------------------------------
  NUMBER OF    7    SOLE VOTING POWER
   SHARES
BENEFICIALLY        957,628 common shares (4.4%)
  OWNED BY     -----------------------------------------------------------------
    EACH       8    SHARED VOTING POWER
 REPORTING
   PERSON           0
    WITH       -----------------------------------------------------------------
               9    SOLE DISPOSITIVE POWER

                    957,628
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    0
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     For the reporting person listed on this page, 957,628; for
     all reporting persons as a group, 4,083,914 shares (18.9%)
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES (See Instructions)

     (TM)
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     18.9%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON

     PN
--------------------------------------------------------------------------------

                                        3



--------------------------------------------------------------------------------
1    NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

     The D3 Family Bulldog Fund, L.P.
--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
     (See Instructions)
                                                                 (a)  [X]
                                                                 (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY

--------------------------------------------------------------------------------
4    SOURCE OF FUNDS (See Instructions)

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) or 2(e)                                   [ ]

--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     Washington
--------------------------------------------------------------------------------
  NUMBER OF    7    SOLE VOTING POWER
   SHARES
BENEFICIALLY        2,423,995 common shares (11.2%)
  OWNED BY     -----------------------------------------------------------------
    EACH       8    SHARED VOTING POWER
 REPORTING
   PERSON           0
    WITH       -----------------------------------------------------------------
               9    SOLE DISPOSITIVE POWER

                    2,423,995
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    0
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     For the reporting person listed on this page, 2,423,995; for
     all reporting persons as a group, 4,083,914 shares (18.9%)
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES (See Instructions)

     (TM)
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     18.9%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON

     PN
--------------------------------------------------------------------------------

                                        4



--------------------------------------------------------------------------------
1    NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

     Nierenberg Investment Management Company, Inc.
--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
     (See Instructions)
                                                                 (a)  [X]
                                                                 (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY

--------------------------------------------------------------------------------
4    SOURCE OF FUNDS (See Instructions)

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) or 2(e)                                   [ ]

--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     Washington
--------------------------------------------------------------------------------
  NUMBER OF    7    SOLE VOTING POWER
   SHARES
BENEFICIALLY        0
  OWNED BY     -----------------------------------------------------------------
    EACH       8    SHARED VOTING POWER
 REPORTING
   PERSON           4,083,914 shares (18.9%)
    WITH       -----------------------------------------------------------------
               9    SOLE DISPOSITIVE POWER

                    0
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    4,083,914 shares
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     For the reporting person listed on this page, 4,083,914; for
     all reporting persons as a group, 4,083,914 shares (18.9%)
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES
     (See Instructions)

     (TM)
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     18.9%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON

     PN
--------------------------------------------------------------------------------

                                        5



--------------------------------------------------------------------------------
1    NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

     Nierenberg Investment Management Offshore, Inc.
--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
     (See Instructions)
                                                                 (a)  [X]
                                                                 (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY

--------------------------------------------------------------------------------
4    SOURCE OF FUNDS (See Instructions)

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) or 2(e)                                   [ ]

--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     Bahamas
--------------------------------------------------------------------------------
  NUMBER OF    7    SOLE VOTING POWER
   SHARES
BENEFICIALLY        0
  OWNED BY     -----------------------------------------------------------------
    EACH       8    SHARED VOTING POWER
 REPORTING
   PERSON           957,628 common shares (4.4%)
    WITH       -----------------------------------------------------------------
               9    SOLE DISPOSITIVE POWER

                    0
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    957,628 common shares
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     For the reporting person listed on this page, 957,628; for
     all reporting persons as a group, 4,083,914 shares (18.9%)
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES (See Instructions)

     (TM)
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     18.9%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON

     PN
--------------------------------------------------------------------------------

                                        6



      This  Amendment  No. 10 to  Schedule  13D (this  "Amendment")  amends  the
below-indicated  items from the Schedule 13D previously filed by or on behalf of
the  undersigned  parties (the  "Reporting  Persons") (the "Schedule  13D"),  by
supplementing such Items with the information below:

Item 4. Purpose of Transaction

The Street threw BABY out with the bathwater after the company missed  consensus
earnings estimates by a penny on March 3. Over the next five trading days, until
its  intra-day  low May 9, BABY's share price fell 19%. We  concluded  that this
sell-off was excessive; therefore, we bought 225,000 more shares on May 9, 2007.

In addition to being BABY's  largest  shareholder  today,  the  President of our
General  Partner has been an investor in BABY since 1989 and served on its Board
of Directors from 1989-2005.  We believe that the company has strong  management
and  governance,  an  enviable  market  share in its newborn  hearing  screening
business,  substantial recurring revenues,  exciting new products,  and a proven
growth strategy, which combines 10%+ organic growth with shrewd acquisitions.

Jim Hawkins,  BABY's CEO, has an excellent  track record  finding,  making,  and
assimilating  acquisitions.  He consummated six at his prior company and five so
far at BABY.  Typically  BABY  acquires  companies  at a small  premium to their
revenue run rates. The acquisitions have been immediately  accretive.  Investors
should remember several things about BABY's  acquisition  plans: Mr. Hawkins has
said on each of his last two  earnings  calls that he  intends to resume  making
acquisitions  in the  second  half of this  year  and that he  expects,  through
acquisitions  and organic  growth,  to exit 2008 at a $250  million  revenue run
rate. If he were to buy $50 million of incremental revenue in the second half of
this year,  so that his year end 2007 revenue run rate were  approximately  $170
million,  and if the market were to value BABY at three  times that  revenue run
rate, BABY's market cap could end this year at over $500 million,  approximately
$22 per share (assuming two million more shares).

Given the company's rapid recent growth, and its excellent growth prospects,  we
support  management's  recent  decisions to invest in  infrastructure  to better
manage the growth and to invest in new hearing and neurology  products,  even at
the expense of a penny per share in the March quarter.

In closing,  we note one additional  possible  reason for BABY's  earnings miss,
something  nobody  mentioned  on the May 3 earnings  call,  and one for which we
believe BABY itself is blameless.  In the company's proxy statement for its 2007
annual  meeting,  BABY disclosed that its 2006 audit and audit related bill from
Deloitte & Touche had  ballooned  from  $584,000 in 2005 to $1.369  million!  We
suspect that some of this expense may have  impacted  BABY's first  quarter 2007
results.

Deloitte & Touche's 2006 charges strike us as extraordinary  and excessive for a
company as small as BABY: to extract $1.369 million to audit a company with only
$90 million of revenues is outrageous.  In the post-Sarbanes-Oxley world we find
ourselves in today, too many audit firms are abusing their oligopolistic pricing
power to the detriment of their clients and their clients' shareholders. We will
not stand for it. It is wasting money and eroding the competitiveness of

                                        7



America's  companies  and our capital  markets.  We are voting all of our shares
against the reappointment of Deloitte & Touche as BABY's auditor. We urge BABY's
board and  management  to return  audit  costs to 2005  levels,  with or without
Deloitte.  We do not blame BABY's  management  and board for this  problem;  the
problem is much  bigger than this small  company.  BABY should not be thrown out
which the bathwater just because Deloitte gave it a bath.

                                      *****

By reporting the information contained in this Amendment,  the Reporting Persons
do not intend to solicit, nor are they soliciting, proxies or consents from, nor
seeking or  requesting  any other  action by, any of the other  stockholders  of
BABY.

The previous statements as to the views of the Reporting Persons regarding their
investment in BABY represent  solely their own analyses and judgments,  based on
publicly-available  information and their own internal evaluation thereof. Those
statements are not intended,  and should not be relied on, as investment  advice
to any other investor or prospective  investor.  To the extent those  statements
reflect  assessments of possible  future  developments,  those  assessments  are
inherently  subject to the  uncertainties  associated  with all  assessments  of
future  events;  actual  developments  may  materially  differ  as a  result  of
circumstances  affecting BABY and/or  extrinsic  factors such as developments in
the  company's  industry and the economic  environment.  The  Reporting  Persons
reserve the right to change their internal  evaluation of this investment in the
future,  as well as to increase or decrease their investment  depending on their
evaluation,  without  further  amending  the  Schedule 13D except as required by
applicable rules.

Item 5. Interest in Securities of the Issuer.

      (a, b) The Reporting Persons, in the aggregate, beneficially own 4,083,914
common shares, constituting approximately 18.9% of the outstanding Shares.

      (c) During the past sixty (60) days the following purchases of Shares were
made by D3 Family Funds in open market transactions:

      Fund                     Transaction Date   Shares Bought   Price
      ----                     ----------------   -------------   -----
      D3 Family Fund, L.P              5/9/2007         12,720    14.86
      D3 Family Bulldog, LP            5/9/2007        146,810    14.86
      DIII Offshore Fund, LP           5/9/2007         65,470    14.86

Item 6. Material to be filed as Exhibits

      Exhibit 1 to this Amendment is the joint filing agreement pursuant to
which all of the filing persons have authorized the filing of this Amendment as
a group.

                                        8



                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, each of the
undersigned certifies that the information set forth in the Statement is true,
complete and correct.

                                            D3 Family Fund, L.P., and D3 Bulldog
                                            Fund, L.P.,

                                            By: Nierenberg Investment Management
                                                Company, Inc.

                                            Its: General Partner
May 14, 2007                                By: /s/ David Nierenberg
------------                                ------------------------------------
                                                 David Nierenberg, President

                                            DIII Offshore Fund, L.P.

                                            By: Nierenberg Investment Management
                                                Offshore, Inc.

                                            Its: General Partner

May 14, 2007                                By: /s/ David Nierenberg
------------                                ------------------------------------
                                                 David Nierenberg, President

                                            Nierenberg Investment Management
                                               Company, Inc.

May 14, 2007                                By: /s/ David Nierenberg
------------                                ------------------------------------
                                                 David Nierenberg, President

                                            Nierenberg Investment Management
                                               Offshore, Inc.

May 14, 2007                                By: /s/ David Nierenberg
------------                                ------------------------------------
                                                 David Nierenberg, President

                                        9



                                                                       Exhibit 1

                             JOINT FILING AGREEMENT

      WHEREAS, the undersigned (collectively, the "Reporting Persons") from time
to time make filings with the Securities and Exchange Commission pursuant to
Regulation 13D-G under the Securities Exchange Act of 1934, as amended; and

      WHEREAS, the Reporting Persons prefer to make joint filings on behalf of
all Reporting Persons rather than individual filings on behalf of each of the
Reporting Persons;

      NOW, THEREFORE, the undersigned hereby agree as follows with each of the
other Reporting Persons:

      1. Each of the Reporting Persons is individually eligible to make joint
filings.

      2. Each of the Reporting Persons is responsible for timely making joint
filings and any amendments thereto.

      3. Each of the Reporting Persons is responsible for the completeness and
accuracy of the information concerning such person contained in joint filings.

      4. None of the Reporting Persons is responsible for the completeness or
accuracy of the information concerning the other Reporting Persons contained in
joint filings, unless such person knows or has reason to believe that such
information is inaccurate.

      5. This Joint Filing Agreement amends, restates and supersedes the Joint
Filing Agreement dated July 5, 2006 by and among the undersigned, D(3)
Children's Fund, L.P. and D(3) Family Retirement Fund, L.P.

                                       10



      6. The undersigned agree that each joint filing made on or after the date
hereof will be, and any amendment thereto will be, made on behalf of each of the
Reporting Persons.

                                            D3 Family Fund, L.P., and D3 Bulldog
                                            Fund, L.P.

                                            By: Nierenberg Investment Management
                                                Company, Inc.

                                            Its: General Partner

July 24, 2006                               By: /s/ David Nierenberg
-------------                               ------------------------------------
                                                   David Nierenberg, President

                                            DIII Offshore Fund, L.P.

                                            By: Nierenberg Investment Management
                                                Offshore, Inc.

                                            Its: General Partner

July 24, 2006                               By: /s/ David Nierenberg
-------------                               ------------------------------------
                                                   David Nierenberg, President

                                            Nierenberg Investment Management
                                                 Company, Inc.

July 24, 2006                               By: /s/ David Nierenberg
-------------                               ------------------------------------
                                                   David Nierenberg, President

                                            Nierenberg Investment Management
                                                 Offshore, Inc.

July 24, 2006                               By: /s/ David Nierenberg
-------------                               ------------------------------------
                                                   David Nierenberg, President

                                       11