<PAGE>

                                                                   Exhibit 10.19


THIS WARRANT AND THE SHARES ISSUABLE HEREUNDER HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED, OR
OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT
OR PURSUANT TO RULE 144 OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE
CORPORATION AND ITS COUNSEL, THAT SUCH REGISTRATION IS NOT REQUIRED.


                           WARRANT TO PURCHASE STOCK

         Corporation:  Sonic Innovations, Inc., a Delaware corporation
           Number of Shares:  Silicon Share Number (as defined below)
                   Class of Stock:  Series D Preferred Stock
                    Initial Exercise Price: $2.00 per share
                         Issue Date: December 22, 1999
                       Expiration Date: December 22, 2004


     THIS WARRANT CERTIFIES THAT, for the agreed upon value of $1.00 and for
other good and valuable consideration, SILICON VALLEY BANK ("Holder") is
entitled to purchase the number of fully paid and nonassessable shares of the
class of securities (the "Shares") of the corporation (the "Company") at the
initial exercise price per Share (the "Warrant Price") all as set forth above
and as adjusted pursuant to Article 2 of this Warrant, subject to the provisions
and upon the terms and conditions set forth in this Warrant.

     "Silicon Share Number" shall mean 59,009, provided that if the Company
                                               --------
consummates an initial public offering of its common stock on or before May 31,
2000, then "Silicon Share Number" shall mean 39,340

ARTICLE 1. EXERCISE.
           --------

           1.1  Method of Exercise.  Holder may exercise this Warrant by
                ------------------
delivering a duly executed Notice of Exercise in substantially the form attached
as Appendix 1 to the principal office of the Company.  Unless Holder is
exercising the conversion right set forth in Section 1.2, Holder shall also
deliver to the Company a check for the aggregate Warrant Price for the Shares
being purchased.

           1.2   Conversion Right.  In lieu of exercising this Warrant as
                 ----------------
specified in Section 1.1, Holder may from time to time convert this Warrant, in
whole or in part, into a number of Shares determined by dividing (a) the
aggregate fair market value of the Shares or other securities otherwise issuable
upon exercise of this Warrant minus the aggregate Warrant Price of such Shares
by (b) the fair market value of one Share.  The fair market value of the Shares
shall be determined pursuant to Section 1.4.

           1.3    Intentionally Omitted
                  ---------------------
<PAGE>

           1.4  Fair Market Value.  If the Shares are traded in a public market,
                -----------------
the fair market value of the Shares shall be the closing price of the Shares (or
the closing price of the Company's stock into which the Shares are convertible)
reported for the business day immediately before Holder delivers its Notice of
Exercise to the Company.  If the Shares are not traded in a public market, the
Board of Directors of the Company shall determine fair market value in its
reasonable good faith judgment.  The foregoing notwithstanding, if Holder
advises the Board of Directors in writing that Holder disagrees with such
determination, then the Company and Holder shall promptly agree upon a reputable
investment banking firm to undertake such valuation.  If the valuation of such
investment banking firm is greater than that determined by the Board of
Directors, then all fees and expenses of such investment banking firm shall be
paid by the Company.  In all other circumstances, such fees and expenses shall
be paid by Holder.

           1.5   Delivery of Certificate and New Warrant.  Promptly after Holder
                 ---------------------------------------
exercises or converts this Warrant, the Company shall deliver to Holder
certificates for the Shares acquired and, if this Warrant has not been fully
exercised or converted and has not expired, a new Warrant representing the
Shares not so acquired.

           1.6   Replacement of Warrants.  On receipt of evidence reasonably
                 -----------------------
satisfactory to the Company of the loss, theft, destruction or mutilation of
this Warrant and, in the case of loss, theft or destruction, on delivery of an
indemnity agreement reasonably satisfactory in form and amount to the Company
or, in the case of mutilation, on surrender and cancellation of this Warrant,
the Company at its expense shall execute and deliver, in lieu of this Warrant, a
new warrant of like tenor.

           1.7   Repurchase on Sale, Merger, or Consolidation of the Company.
                 -----------------------------------------------------------

                 1.7.1.    "Acquisition".  For the purpose of this Warrant,
                           -------------
"Acquisition" means any sale, license, or other disposition of all or
substantially all of the assets of the Company, or any reorganization,
consolidation, or merger of the Company where the holders of the Company's
securities before the transaction beneficially own less than 50% of the
outstanding voting securities of the surviving entity after the transaction.

                 1.7.2.    Assumption of Warrant. Upon the closing of any
                           ---------------------
Acquisition the successor entity shall assume the obligations of this Warrant,
and this Warrant shall be exercisable for the same securities, cash, and
property as would be payable for the Shares issuable upon exercise of the
unexercised portion of this Warrant as if such Shares were outstanding on the
record date for the Acquisition and subsequent closing. The Warrant Price shall
be adjusted accordingly.

                 1.7.3.    Purchase Right. Notwithstanding the foregoing, at the
                           --------------
election of Holder, the Company shall purchase the unexercised portion of this
Warrant for cash upon the closing of any Acquisition for an amount equal to (a)
the fair market value of any consideration that would have been received by
Holder in consideration of the Shares had Holder exercised the unexercised
portion of this Warrant immediately before the record date for determining the
shareholders entitled to participate in the proceeds of the Acquisition, less
(b) the aggregate Warrant Price of the Shares, but in no event less than zero.

                                       2
<PAGE>

ARTICLE 2.  ADJUSTMENTS TO THE SHARES.
            -------------------------

            2.1  Stock Dividends, Splits, Etc. If the Company declares or pays a
                 ----------------------------
dividend on its common stock (or the Shares if the Shares are securities other
than common stock) payable in common stock, or other securities, subdivides the
outstanding common stock into a greater amount of common stock, or, if the
Shares are securities other than common stock, subdivides the Shares in a
transaction that increases the amount of common stock into which the Shares are
convertible, then upon exercise of this Warrant, for each Share acquired, Holder
shall receive, without cost to Holder, the total number and kind of securities
to which Holder would have been entitled had Holder owned the Shares of record
as of the date the dividend or subdivision occurred.

            2.2  Reclassification, Exchange or Substitution.  Upon any
                 ------------------------------------------
reclassification, exchange, substitution, or other event that results in a
change of the number and/or class of the securities issuable upon exercise or
conversion of this Warrant, Holder shall be entitled to receive, upon exercise
or conversion of this Warrant, the number and kind of securities and property
that Holder would have received for the Shares if this Warrant had been
exercised immediately before such reclassification, exchange, substitution, or
other event.  Such an event shall include any automatic conversion of the
outstanding or issuable securities of the Company of the same class or series as
the Shares to common stock pursuant to the terms of the Company's Articles of
Incorporation upon the closing of a registered public offering of the Company's
common stock.  The Company or its successor shall promptly issue to Holder a new
Warrant for such new securities or other property.  The new Warrant shall
provide for adjustments which shall be as nearly equivalent as may be
practicable to the adjustments provided for in this Article 2 including, without
limitation, adjustments to the Warrant Price and to the number of securities or
property issuable upon exercise of the new Warrant.  The provisions of this
Section 2.2 shall similarly apply to successive reclassifications, exchanges,
substitutions, or other events.

            2.3  Adjustments for Combinations, Etc. If the outstanding Shares
                 ---------------------------------
are combined or consolidated, by reclassification or otherwise, into a lesser
number of shares, the Warrant Price shall be proportionately increased.

            2.4  Adjustments for Diluting Issuances.  The Warrant Price and the
                 ----------------------------------
number of Shares issuable upon exercise of this Warrant or, if the Shares are
Preferred Stock, the number of shares of common stock issuable upon conversion
of the Shares, shall be subject to adjustment, from time to time in the manner
set forth on Exhibit A in the event of Diluting Issuances (as defined on Exhibit
A).

                                       3
<PAGE>

            2.5  No Impairment.  The Company shall not, by amendment of its
                 -------------
Articles of Incorporation or through a reorganization, transfer of assets,
consolidation, merger, dissolution, issue, or sale of securities or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the terms to be observed or performed under this Warrant by the Company, but
shall at all times in good faith assist in carrying out of all the provisions of
this Article 2 and in taking all such action as may be necessary or appropriate
to protect Holder's rights under this Article against impairment.  If the
Company takes any action affecting the Shares or its common stock other than as
described above that adversely affects Holder's rights under this Warrant, the
Warrant Price shall be adjusted downward and the number of Shares issuable upon
exercise of this Warrant shall be adjusted upward in such a manner that the
aggregate Warrant Price of this Warrant is unchanged.

            2.6  Fractional Shares.  No fractional Shares shall be issuable upon
                 -----------------
exercise or conversion of the Warrant and the number of Shares to be issued
shall be rounded down to the nearest whole Share.  If a fractional share
interest arises upon any exercise or conversion of the Warrant, the Company
shall eliminate such fractional share interest by paying Holder amount computed
by multiplying the fractional interest by the fair market value of a full Share.

            2.7  Certificate as to Adjustments.  Upon each adjustment of the
                 -----------------------------
Warrant Price, the Company at its expense shall promptly compute such
adjustment, and furnish Holder with a certificate of its Chief Financial Officer
setting forth such adjustment and the facts upon which such adjustment is based.
The Company shall, upon written request, furnish Holder a certificate setting
forth the Warrant Price in effect upon the date thereof and the series of
adjustments leading to such Warrant Price.

ARTICLE 3.  REPRESENTATIONS AND COVENANTS OF THE COMPANY.
            --------------------------------------------

            3.1  Representations and Warranties.  The Company hereby represents
                 ------------------------------
and warrants to the Holder as follows:

                 (a) The initial Warrant Price referenced on the first page of
this Warrant is not greater than (i) the price per share at which the Shares
were last issued in an arms-length transaction in which at least $500,000 of the
Shares were sold and (ii) the fair market value of the Shares as of the date of
this Warrant.

                 (b) All Shares which may be issued upon the exercise of the
purchase right represented by this Warrant, and all securities, if any, issuable
upon conversion of the Shares, shall, upon issuance, be duly authorized, validly
issued, fully paid and nonassessable, and free of any liens and encumbrances
except for restrictions on transfer provided for herein or under applicable
federal and state securities laws.

                 (c) The Capitalization Table attached to this Warrant is true
and complete as of the Issue Date.

                                       4
<PAGE>

            3.2  Notice of Certain Events.  If the Company proposes at any time
                 ------------------------
(a) to declare any dividend or distribution upon its common stock, whether in
cash, property, stock, or other securities and whether or not a regular cash
dividend; (b) to offer for subscription pro rata to the holders of any class or
series of its stock any additional shares of stock of any class or series or
other rights; (c) to effect any reclassification or recapitalization of common
stock; (d) to merge or consolidate with or into any other corporation, or sell,
lease, license, or convey all or substantially all of its assets, or to
liquidate, dissolve or wind up; or (e) offer holders of registration rights the
opportunity to participate in an underwritten public offering of the company's
securities for cash, then, in connection with each such event, the Company shall
give Holder (1) at least 20 days prior written notice of the date on which a
record will be taken for such dividend, distribution, or subscription rights
(and specifying the date on which the holders of common stock will be entitled
thereto) or for determining rights to vote, if any, in respect of the matters
referred to in (c) and (d) above; (2) in the case of the matters referred to in
(c) and (d) above at least 20 days prior written notice of the date when the
same will take place (and specifying the date on which the holders of common
stock will be entitled to exchange their common stock for securities or other
property deliverable upon the occurrence of such event); and (3) in the case of
the matter referred to in (e) above, the same notice as is given to the holders
of such registration rights.

          3.3  Information Rights.  So long as the Holder holds this Warrant
               ------------------
and/or any of the Shares, the Company shall deliver to the Holder (a) promptly
after mailing, copies of all notices or other written communications to the
shareholders of the Company, (b) within ninety (90) days after the end of each
fiscal year of the Company, the annual audited financial statements of the
Company certified by independent public accountants of recognized standing and
(c) such other financial statements required under and in accordance with any
loan documents between Holder and the Company (or if there are no such
requirements [or if the subject loan(s) no longer are outstanding]), then within
forty-five (45) days after the end of each of the first three quarters of each
fiscal year, the Company's quarterly, unaudited financial statements.

            3.4  Registration Under Securities Act of 1933, as amended.  The
                 -----------------------------------------------------
Company agrees that the Shares or, if the Shares are convertible into common
stock of the Company, such common stock, shall be subject to the registration
rights set forth on Exhibit B, if attached.

ARTICLE 4.  MISCELLANEOUS.
            -------------

            4.1  Term; Notice of Expiration.  This Warrant is exercisable, in
                 --------------------------
whole or in part, at any time and from time to time on or before the Expiration
Date set forth above.  The Company shall give Holder written notice of Holder's
right to exercise this Warrant in the form attached as Appendix 2 not more than
90 days and not less than 30 days before the Expiration Date. If the notice is
not so given, the Expiration Date shall automatically be extended until 30 days
after the date the Company delivers the notice to Holder.

            4.2  Legends.  This Warrant and the Shares (and the securities
                 -------
issuable, directly or indirectly, upon conversion of the Shares, if any) shall
be imprinted with a legend in substantially the following form:

                                       5
<PAGE>

     THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
     AMENDED, AND MAY NOT BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED WITHOUT AN
     EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT OR PURSUANT TO RULE 144 OR AN
     OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE CORPORATION AND ITS
     COUNSEL THAT SUCH REGISTRATION IS NOT REQUIRED.

            4.3  Compliance with Securities Laws on Transfer.  This Warrant and
                 -------------------------------------------
the Shares issuable upon exercise this Warrant (and the securities issuable,
directly or indirectly, upon conversion of the Shares, if any) may not be
transferred or assigned in whole or in part without compliance with applicable
federal and state securities laws by the transferor and the transferee
(including, without limitation, the delivery of investment representation
letters and legal opinions reasonably satisfactory to the Company, as reasonably
requested by the Company).  The Company shall not require Holder to provide an
opinion of counsel if the transfer is to an affiliate of Holder or if there is
no material question as to the availability of current information as referenced
in Rule 144(c), Holder represents that it has complied with Rule 144(d) and (e)
in reasonable detail, the selling broker represents that it has complied with
Rule 144(f), and the Company is provided with a copy of Holder s notice of
proposed sale.

            4.4  Transfer Procedure.   Subject to the provisions of Section 4.3,
                 ------------------
Holder may transfer all or part of this Warrant or the Shares issuable upon
exercise of this Warrant (or the securities issuable, directly or indirectly,
upon conversion of the Shares, if any) by giving the Company notice of the
portion of the Warrant being transferred setting forth the name, address and
taxpayer identification number of the transferee and surrendering the Warrant to
the Company for reissuance to the transferee(s) (and Holder, if applicable);

provided, however, that Holder may transfer all or part of this Warrant to its
--------  -------
affiliates, including, without limitation, Silicon Valley Bancshares and The
Silicon Valley Bank Foundation, at any time without notice to the Company.  The
terms and conditions of this Warrant shall inure to the benefit of, and be
binding upon, the Company and the holders hereof and their respective permitted
successors and assigns.

            4.5  Notices.  All notices and other communications from the Company
                 -------
to the Holder, or vice versa, shall be deemed delivered and effective when given
personally or mailed by first-class registered or certified mail, postage
prepaid, at such address as may have been furnished to the Company or the
Holder, as the case may be, in writing by the Company or such holder from time
to time.   All notices to Holder should be sent to the following address:

                 Treasury Department
                 Silicon Valley Bank
                 3003 Tasman Drive HG110
                 Santa Clara, CA  95054

            4.6  Waiver. This Warrant and any term hereof may be changed,
                 ------
waived, discharged or terminated only by an instrument in writing signed by the
party against which enforcement of such change, waiver, discharge or termination
is sought.

                                       6
<PAGE>

            4.7  Attorneys Fees. In the event of any dispute between the parties
                 --------------
concerning the terms and provisions of this Warrant, the party prevailing in
such dispute shall be entitled to collect from the other party all costs
incurred in such dispute, including reasonable attorneys' fees.

            4.8    Governing Law. This Warrant shall be governed by and
                   -------------
construed in accordance with the laws of the State of California, without giving
effect to its principles regarding conflicts of law.


                                    "COMPANY"

                                    Sonic Innovations, Inc.


                                    By: /s/ Andrew G. Raguskus
                                        ---------------------------------
                                    Name:  Andrew G. Raguskus
                                          -------------------------------
                                           (Print)
                                    Title: Chairman of the Board, President or
                                           Vice President


                                    By: /s/ S. L. Wilson
                                        ---------------------------------
                                    Name: S. L. Wilson
                                          -------------------------------
                                           (Print)
                                    Title: Chief Financial Officer, Secretary,
                                           Assistant Treasurer or Assistant
                                           Secretary

                                       7
<PAGE>

                                  APPENDIX 1


                              NOTICE OF EXERCISE
                              ------------------



     1.   The undersigned hereby elects to purchase _____________ shares of the
Common/Series ______ Preferred [strike one] Stock of __________________________
pursuant to the terms of the attached Warrant, and tenders herewith payment of
the purchase price of such shares in full.

     1.   The undersigned hereby elects to convert the attached Warrant into
Shares/cash [strike one] in the manner specified in the Warrant.  This
conversion is exercised with respect to _____________________ of the Shares
covered by the Warrant.

     [Strike paragraph that does not apply.]

     2.   Please issue a certificate or certificates representing said shares in
the name of the undersigned or in such other name as is specified below:

               ___________________________________________
                    (Name)


               ___________________________________________

               ___________________________________________
                    (Address)

     3.   The undersigned represents it is acquiring the shares solely for its
own account and not as a nominee for any other party and not with a view toward
the resale or distribution thereof except in compliance with applicable
securities laws.

                                    ____________________________________
                                         (Signature)

____________________
     (Date)
<PAGE>

                                  APPENDIX 2

                    Notice that Warrant Is About to Expire
                    --------------------------------------

                          _____________________, ___


(Name of Holder)

(Address of Holder)

Attn: Chief Financial Officer


Dear :_______________________


     This is to advise you that the Warrant issued to you described below will
expire on  _________________________, 19___.

     Issuer:

     Issue Date:

     Class of Security Issuable:

     Exercise Price per Share:

     Number of Shares Issuable:

     Procedure for Exercise:

     Please contact [name of contact person at (phone number)] with any
questions you may have concerning exercise of the Warrant. This is your only
notice of pending expiration.

                                   ---------------------------------------------
                                   (Name of Issuer)

                                   By:
                                   _____________________________________________

                                   Its:
                                   _____________________________________________

<PAGE>

                                   EXHIBIT A
                                   ---------

                           Anti-Dilution Provisions


     In the event of the issuance (a "Diluting Issuance") by the Company, after
the Issue Date of the Warrant, of securities at a price per share less than the
Warrant Price, or, if the Shares are common stock, less than the then conversion
price of the Company's Series __ Preferred Stock, then the number of shares of
common stock issuable upon conversion of the Shares, or if the Shares are common
stock, the number of Shares issuable upon exercise of the Warrant, shall be
adjusted as a result of Diluting Issuances in accordance with the Holder's
standard form of Anti-Dilution Agreement in effect on the Issue Date.

     Under no circumstances shall the aggregate Warrant Price payable by the
Holder upon exercise of the Warrant increase as a result of any adjustment
arising from a Diluting Issuance.
<PAGE>

                                   EXHIBIT B
                                   ---------

                              Registration Rights
                              -------------------


     The Shares (if common stock), or the common stock issuable upon conversion
of the Shares, shall be deemed "registrable securities" or otherwise entitled to
"piggy back" registration rights in accordance with the terms of the following
agreement (the "Agreement") between the Company and its investor(s):


     ____________________________________________________________
          [Identify Agreement by date, title and parties.  If no Agreement
          exists, indicate by "none".]

     The Company agrees that no amendments will be made to the Agreement which
would have an adverse impact on Holder's registration rights thereunder without
the consent of Holder.  By acceptance of the Warrant to which this Exhibit B is
attached, Holder shall be deemed to be a party to the Agreement, unless Holder
otherwise elects not to become or to cease being a party thereto.

     If no Agreement exists, then the Company and the Holder shall enter into
Holder's standard form of Registration Rights Agreement as in effect on the
Issue Date of the Warrant.
<PAGE>

                              SILICON VALLEY BANK
                         REGISTRATION RIGHTS AGREEMENT


     THIS REGISTRATION RIGHTS AGREEMENT is entered into as of December 22, 1999,
by and between SILICON VALLEY BANK ("Purchaser") and Sonic Innovations, Inc.

                                   RECITALS
                                   --------

     A.   Concurrently with the execution of this Agreement, the Purchaser is
purchasing from the Company a Warrant to Purchase Stock (the "Warrant") pursuant
to which Purchaser has the right to acquire from the Company the Shares (as
defined in the Warrant).

     B.   By this Agreement, the Purchaser and the Company desire to set forth
the registration rights of the Shares all as provided herein.

          NOW, THEREFORE, in consideration of the mutual promises, covenants and
conditions hereinafter set forth, the parties hereto mutually agree as follows:

     1.   Registration Rights.  The Company covenants and agrees as follows:
          -------------------

          1.1  Definitions.  For purposes of this Section 1:
               -----------

               (a) The term "register," "registered," and "registration" refer
to a registration effected by preparing and filing a registration statement or
similar document in compliance with the Securities Act of 1933, as amended (the
"Securities Act"), and the declaration or ordering of effectiveness of such
registration statement or document;

               (b) The term "Registrable Securities" means (i) the Shares (if
Common Stock) or all shares of Common Stock of the Company issuable or issued
upon conversion of the Shares and (ii) any Common Stock of the Company issued as
(or issuable upon the conversion or exercise of any warrant, right or other
security which is issued as) a dividend or other distribution with respect to,
or in exchange for or in replacement of, any stock referred to in (i).

               (c) The terms "Holder" or "Holders" means the Purchaser or
qualifying transferees under subsection 1.8 hereof who hold Registrable
Securities.

               (d) The term "SEC" means the Securities and Exchange Commission.
<PAGE>

          1.2  Company Registration.
               --------------------

               (a) Registration. If at any time or from time to time, the
                   ------------
Company shall determine to register any of its securities, for its own account
or the account of any of its shareholders, other than a registration on Form S-1
or S-8 relating solely to employee stock option or purchase plans, or a
registration on Form S-4 relating solely to an SEC Rule 145 transaction, or a
registration on any other form (other than Form S-1, S-2, S-3 or S-18, or their
successor forms) or any successor to such forms, which does not include
substantially the same information as would be required to be included in a
registration statement covering the sale of Registrable Securities, the Company
will:

                   (i)   promptly give to each Holder written notice thereof
(which shall include a list of the jurisdictions in which the Company intends to
attempt to qualify such securities under the applicable blue sky or other state
securities laws); and

                   (ii)  include in such registration (and compliance), and in
any underwriting involved therein, all the Registrable Securities specified in a
written request or requests, made within 30 days after receipt of such written
notice from the Company, by any Holder or Holders, except as set forth in
subsection 1.2(b) below.

                   (b)   Underwriting. If the registration of which the Company
                         ------------
gives notice is for a registered public offering involving an underwriting, the
Company shall so advise the Holders as a part of the written notice given
pursuant to subsection 1.2(a)(i). In such event the right of any Holder to
registration pursuant to this subsection 1.2 shall be conditioned upon such
Holder's participation in such underwriting and the inclusion of such Holder's
Registrable Securities in the underwriting to the extent provided herein. All
Holders proposing to distribute their securities through such underwriting shall
(together with the Company and the other shareholders distributing their
securities through such underwriting) enter into an underwriting agreement in
customary form with the underwriter or underwriters selected for such
underwriting by the Company.

          1.3  Expenses of Registration.  All expenses incurred in connection
               ------------------------
with any registration, qualification or compliance pursuant to this Section 1
including without limitation, all registration, filing and qualification fees,
printing expenses, fees and disbursements of counsel for the Company and
expenses of any special audits incidental to or required by such registration,
shall be borne by the Company except the Company shall not be required to pay
underwriters' fees, discounts or commissions relating to Registrable Securities.
All expenses of any registered offering not otherwise borne by the Company shall
be borne pro rata among the Holders participating in the offering and the
Company.

          1.4  Registration Procedures.  In the case of each registration,
               -----------------------
qualification or compliance effected by the Company pursuant to this
Registration Rights Agreement, the Company will keep each Holder participating
therein advised in writing as to the initiation of each registration,
qualification and compliance and as to the completion thereof.  Except as
otherwise provided in subsection 1.3, at its expense the Company will:

                                       2
<PAGE>

               (a) Prepare and file with the SEC a registration statement with
respect to such Registrable Securities and use its best efforts to cause such
registration statement to become effective, and, upon the request of the Holders
of a majority of the Registrable Securities registered thereunder, keep such
registration statement effective for up to 120 days.

               (b) Prepare and file with the SEC such amendments and supplements
to such registration statement and the prospectus used in connection with such
registration statement as may be necessary to comply with the provisions of the
Securities Act with respect to the disposition of all securities covered by such
registration statement.

               (c) Furnish to the Holders such numbers of copies of a
prospectus, including a preliminary prospectus, in conformity with the
requirements of the Securities Act, and such other documents as they may
reasonably request in order to facilitate the disposition of Registrable
Securities owned by them.

               (d) Use its best efforts to register and qualify the securities
covered by such registration statement under such other securities or Blue Sky
laws of such jurisdictions as shall be reasonably requested by the Holders,
provided that the Company shall not be required in connection therewith or as a
condition thereto to qualify to do business or to file a general consent to
service of process in any such states or jurisdictions.

               (e) In the event of any underwritten public offering, enter into
and perform its obligations under an underwriting agreement, in usual and
customary form, with the managing underwriter of such offering. Each Holder
participating in such underwriting shall also enter into and perform its
obligations under such an agreement.

               (f) Notify each Holder of Registrable Securities covered by such
registration statement at any time when a prospectus relating thereto is
required to be delivered under the Securities Act or the happening of any event
as a result of which the prospectus included in such registration statement, as
then in effect, includes an untrue statement of a material fact or omits to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading in the light of the circumstances then
existing.

          1.5  Indemnification.
               ---------------

               (a) The Company will indemnify each Holder of Registrable
Securities and each of its officers, directors and partners, and each person
controlling such Holder, with respect to which such registration, qualification
or compliance has been effected pursuant to this Rights Agreement, and each
underwriter, if any, and each person who controls any underwriter of the
Registrable Securities held by or issuable to such Holder, against all claims,
losses, expenses, damages and liabilities (or actions in respect thereto)
arising out of or based on any untrue statement (or alleged untrue statement) of
a material fact contained in any prospectus, offering circular or other document
(including any related registration statement, notification or the like)
incident to any such registration, qualification or compliance, or based on any
omission (or alleged

                                       3
<PAGE>

omission) to state therein a material fact required to be stated therein or
necessary to make the statement therein not misleading, or any violation or
alleged violation by the Company of the Securities Act, the Securities Exchange
Act of 1934, as amended, ("Exchange Act") or any state securities law applicable
to the Company or any rule or regulation promulgated under the Securities Act,
the Exchange Act or any such state law and relating to action or inaction
required of the Company in connection with any such registration, qualification
of compliance, and will reimburse each such Holder, each of its officers,
directors and partners, and each person controlling such Holder, each such
underwriter and each person who controls any such underwriter, within a
reasonable amount of time after incurred for any reasonable legal and any other
expenses incurred in connection with investigating, defending or settling any
such claim, loss, damage, liability or action; provided, however, that the
indemnity agreement contained in this subsection 1.5(a) shall not apply to
amounts paid in settlement of any such claim, loss, damage, liability, or action
if such settlement is effected without the consent of the Company (which consent
shall not be unreasonably withheld); and provided further, that the Company will
not be liable in any such case to the extent that any such claim, loss, damage
or liability arises out of or is based on any untrue statement or omission based
upon written information furnished to the Company by an instrument duly executed
by such Holder or underwriter specifically for use therein.

               (b) Each Holder will, if Registrable Securities held by or
issuable to such Holder are included in the securities as to which such
registration, qualification or compliance is being effected, indemnify the
Company, each of its directors and officers, each underwriter, if any, of the
Company's securities covered by such a registration statement, each person who
controls the Company within the meaning of the Securities Act, and each other
such Holder, each of its officers, directors and partners and each person
controlling such Holder, against all claims, losses, expenses, damages and
liabilities (or actions in respect thereof) arising out of or based on any
untrue statement (or alleged untrue statement) of a material fact contained in
any such registration statement, prospectus, offering circular or other
document, or any omission (or alleged omission) to state therein a material fact
required to be stated therein or necessary to make the statements therein not
misleading, and will reimburse the Company, such Holders, such directors,
officers, partners, persons or underwriters for any reasonable legal or any
other expenses incurred in connection with investigating, defending or settling
any such claim, loss, damage, liability or action, in each case to the extent,
but only to the extent, that such untrue statement (or alleged untrue statement)
or omission (or alleged omission) is made in such registration statement,
prospectus, offering circular or other document in reliance upon and in
conformity with written information furnished to the Company by an instrument
duly executed by such Holder specifically for use therein; provided, however,
that the indemnity agreement contained in this subsection 1.5(b) shall not apply
to amounts paid in settlement of any such claim, loss, damage, liability or
action if such settlement is effected without the consent of the Holder, (which
consent shall not be unreasonably withheld); and provided further, that the
total amount for which any Holder shall be liable under this subsection 1.5(b)
shall not in any event exceed the aggregate proceeds received by such Holder
from the sale of Registrable Securities held by such Holder in such
registration.

                                       4
<PAGE>

               (c) Each party entitled to indemnification under this subsection
1.5 (the "Indemnified Party") shall give notice to the party required to provide
indemnification (the "Indemnifying Party") promptly after such Indemnified Party
has actual knowledge of any claim as to which indemnity may be sought, and shall
permit the Indemnifying Party to assume the defense of any such claim or any
litigation resulting therefrom; provided that counsel for the Indemnifying
Party, who shall conduct the defense of such claim or litigation, shall be
approved by the Indemnified Party (whose approval shall not be unreasonably
withheld), and the Indemnified Party may participate in such defense at such
party's expense; and provided further, that the failure of any Indemnified Party
to give notice as provided herein shall not relieve the Indemnifying Party of
its obligations hereunder, unless such failure resulted in prejudice to the
Indemnifying Party; and provided further, that an Indemnified Party (together
with all other Indemnified Parties which may be represented without conflict by
one counsel) shall have the right to retain one separate counsel, with the fees
and expenses to be paid by the Indemnifying Party, if representation of such
Indemnified Party by the counsel retained by the Indemnifying Party would be
inappropriate due to actual or potential differing interests between such
Indemnified Party and any other party represented by such counsel in such
proceeding. No Indemnifying Party, in the defense of any such claim or
litigation, shall, except with the consent of each Indemnified Party, consent to
entry of any judgment or enter into any settlement which does not include as an
unconditional term thereof the giving by the claimant or plaintiff to such
Indemnified Party of a release from all liability in respect to such claim or
litigation.

          1.6  Information by Holder.  Any Holder or Holders of Registrable
               ---------------------
Securities included in any registration shall promptly furnish to the Company
such information regarding such Holder or Holders and the distribution proposed
by such Holder or Holders as the Company may request in writing and as shall be
required in connection with any registration, qualification or compliance
referred to herein.

          1.7  Rule 144 Reporting.  With a view to making available to Holders
               ------------------
the benefits of certain rules and regulations of the SEC which may permit the
sale of the Registrable Securities to the public without registration, the
Company agrees at all times to:

               (a) make and keep public information available, as those terms
are understood and defined in SEC Rule 144, after 90 days after the effective
date of the first registration filed by the Company for an offering of its
securities to the general public;

               (b) file with the SEC in a timely manner all reports and other
documents required of the Company under the Securities Act and the Exchange Act
(at any time after it has become subject to such reporting requirements); and

               (c) so long as a Holder owns any Registrable Securities, to
furnish to such Holder forthwith upon request a written statement by the Company
as to its compliance with the reporting requirements of said Rule 144 (at any
time after 90 days after the effective date of the first registration statement
filed by the Company for an offering of its securities to the general public),
and of the Securities Act and the Exchange Act (at any time after it has become
subject to such reporting requirements), a copy of the most recent annual or
quarterly report of the

                                       5
<PAGE>

Company, and such other reports and documents so filed by the Company as the
Holder may reasonably request in complying with any rule or regulation of the
SEC allowing the Holder to sell any such securities without registration.

          1.8  Transfer of Registration Rights.  Holders' rights to cause the
               -------------------------------
Company to register their securities and keep information available, granted to
them by the Company under subsections 1.2 and 1.7 may be assigned to a
transferee or assignee of a Holder's Registrable Securities not sold to the
public, provided, that the Company is given written notice by such Holder at the
time of or within a reasonable time after said transfer, stating the name and
address of said transferee or assignee and identifying the securities with
respect to which such registration rights are being assigned.  The Company may
prohibit the transfer of any Holders' rights under this subsection 1.8 to any
proposed transferee or assignee who the Company reasonably believes is a
competitor of the Company.

     2.   General.
          -------

          2.1  Waivers and Amendments.  With the written consent of the record
               ----------------------
or beneficial holders of at least a majority of the Registrable Securities, the
obligations of the Company and the rights of the Holders of the Registrable
Securities under this agreement may be waived (either generally or in a
particular instance, either retroactively or prospectively, and either for a
specified period of time or indefinitely), and with the same consent the
Company, when authorized by resolution of its Board of Directors, may enter into
a supplementary agreement for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement;
provided, however, that no such modification, amendment or waiver shall reduce
the aforesaid percentage of Registrable Securities without the consent of all of
the Holders of the Registrable Securities.  Upon the effectuation of each such
waiver, consent, agreement of amendment or modification, the Company shall
promptly give written notice thereof to the record holders of the Registrable
Securities who have not previously consented thereto in writing.  This Agreement
or any provision hereof may be changed, waived, discharged or terminated only by
a statement in writing signed by the party against which enforcement of the
change, waiver, discharge or termination is sought, except to the extent
provided in this subsection 2.1.

          2.2  Governing Law.  This Agreement shall be governed in all respects
               -------------
by the laws of the State of California as such laws are applied to agreements
between California residents entered into and to be performed entirely within
California.

          2.3  Successors and Assigns.  Except as otherwise expressly provided
               ----------------------
herein, the provisions hereof shall inure to the benefit of, and be binding
upon, the successors, assigns, heirs, executors and administrators of the
parties hereto.

          2.4  Entire Agreement.  Except as set forth below, this Agreement and
               ----------------
the other documents delivered pursuant hereto constitute the full and entire
understanding and agreement between the parties with regard to the subjects
hereof and thereof.

                                       6
<PAGE>

          2.5  Notices, etc.  All notices and other communications required or
               ------------
permitted hereunder shall be in writing and shall be mailed by first class mail,
postage prepaid, certified or registered mail, return receipt requested,
addressed (a) if to Holder, at such Holder's address as set forth below, or at
such other address as such Holder shall have furnished to the Company in
writing, or (b) if to the Company, at the Company's address set forth below, or
at such other address as the Company shall have furnished to the Holder in
writing.

          2.6  Severability.  In case any provision of this Agreement shall be
               ------------
invalid, illegal, or unenforceable, the validity, legality and enforceability of
the remaining provisions of this Agreement or any provision of the other
Agreement s shall not in any way be affected or impaired thereby.

          2.7  Titles and Subtitles.  The titles of the sections and subsections
               --------------------
of this Agreement are for convenience of reference only and are not to be
considered in construing this Agreement.

          2.8  Counterparts.  This Agreement may be executed in any number of
               ------------
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.

PURCHASER                          COMPANY

SILICON VALLEY BANK                Sonic Innovations, Inc.

By:  /s/ Ron Sherman               By:  /s/ A. Raguskus
     --------------------------         ----------------------------
Name: Ron Sherman                  Name: Andrew G. Raguskus
     --------------------------         ----------------------------
           (print)                              (print)

Title:                             Title:    Chairman of the Board, President or
              VP                           Vice President
-------------------------------

Address:  _____________________    Address:__________________________
_______________________________            __________________________
_______________________________            __________________________

                                       7
<PAGE>

                              SILICON VALLEY BANK
                            ANTIDILUTION AGREEMENT

     THIS ANTIDILUTION AGREEMENT is entered into as of December 22, 1999, by and
between SILICON VALLEY BANK ("Purchaser") and Sonic Innovations, Inc..

                                   RECITALS
                                   --------

     A.   Concurrently with the execution of this Antidilution Agreement, the
Purchaser is purchasing from the Company a Warrant to Purchase Stock (the
"Warrant') pursuant to which Purchaser has the right to acquire from the Company
the Shares (as defined in the Warrant).

     B.   By this Antidilution Agreement, the Purchaser and the Company desire
to set forth the adjustment in the number of Shares issuable upon exercise of
the Warrant as a result of a Diluting Issuance (as defined in Exhibit A to the
Warrant).

     C.   Capitalized terms used herein shall have the same meaning as set forth
in the Warrant.

          NOW, THEREFORE, in consideration of the mutual promises, covenants and
conditions hereinafter set forth, the parties hereto mutually agree as follows:

          1.   Definitions.  As used in this Antidilution Agreement, the
               -----------
following terms have the following respective meanings:

               (a) "Option" means any right, option, or warrant to subscribe
for, purchase, or otherwise acquire common stock or Convertible Securities.

               (b) "Convertible Securities" means any evidences of indebtedness,
shares of stock, or other securities directly or indirectly convertible into or
exchangeable for common stock.

               (c) "Issue" means to grant, issue, sell, assume, or fix a record
date for determining persons entitled to receive, any security (including
Options), whichever of the foregoing is the first to occur.

               (d) "Additional Common Shares" means all common stock (including
reissued shares) issued (or deemed to be issued pursuant to Section 2) after the
date of the Warrant. Additional Common Shares does not include, however, any
common stock issued in a transaction described in Sections 2.1 and 2.2 of the
Warrant; any common stock Issued upon conversion of preferred stock outstanding
on the date of the Warrant; the Shares; or common stock Issued as incentive or
in a nonfinancing transaction to employees, officers, directors, or consultants
to the Company.
<PAGE>

               (e) The shares of common stock ultimately Issuable upon exercise
of an Option (including the shares of common stock ultimately Issuable upon
conversion or exercise of a Convertible Security Issuable pursuant to an Option)
are deemed to be Issued when the Option is Issued. The shares of common stock
ultimately Issuable upon conversion or exercise of a Convertible Security (other
than a Convertible Security Issued pursuant to an Option) shall be deemed Issued
upon Issuance of the Convertible Security.

     2.   Deemed Issuance of Additional Common Shares.  The shares of common
          -------------------------------------------
stock ultimately Issuable upon exercise of an Option (including the shares of
common stock ultimately Issuable upon conversion or exercise of a Convertible
Security Issuable pursuant to an Option) are deemed to be Issued when the Option
is Issued.  The shares of common stock ultimately Issuable upon conversion or
exercise of a Convertible Security (other than a Convertible Security Issued
pursuant to an Option) shall be deemed Issued upon Issuance of the Convertible
Security.  The maximum amount of common stock Issuable is determined without
regard to any future adjustments permitted under the instrument creating the
Options or Convertible Securities.

     3.   Adjustment of Warrant Price for Diluting Issuances.
          --------------------------------------------------

          3.1  Weighted Average Adjustment.  If the Company issues Additional
               ---------------------------
Common Shares after the date of the Warrant and the consideration per Additional
Common Share (determined pursuant to Section 9) is less than the Warrant Price
in effect immediately before such Issue, the Warrant Price shall be reduced,
concurrently with such Issue, to a price (calculated to the nearest hundredth of
a cent) determined by multiplying the Warrant Price by a fraction:

               (a) the numerator of which is the amount of such common stock
outstanding immediately before such Issue plus the amount of common stock that
the aggregate consideration received by the Company for the Additional Common
Shares would purchase at the Warrant Price in effect immediately before such
Issue, and

               (b)  the denominator of which is the amount of common stock
outstanding immediately before such Issue plus the number of such Additional
Common Shares.

          3.2  Adjustment of Number of Shares.  Upon each adjustment of the
               ------------------------------
Warrant Price, the number of Shares issuable upon exercise of the Warrant shall
be increased to equal the quotient obtained by dividing (a) the product
resulting from multiplying (i) the number of Shares issuable upon exercise of
the Warrant and (ii) the Warrant Price, in each case as in effect immediately
before such adjustment, by (b) the adjusted Warrant Price.

          3.3  Securities Deemed Outstanding.  For the purpose of this Section
               -----------------------------
3, all securities issuable upon exercise of any outstanding Convertible
Securities or Options, warrants, or other rights to acquire securities of the
Company shall be deemed to be outstanding.

     4.   No Adjustment for Issuances Following Deemed Issuances.  No adjustment
          ------------------------------------------------------
to the Warrant Price shall be made upon the exercise of Options or conversion of
Convertible Securities.

                                       2
<PAGE>

     5.   Adjustment Following Changes in Terms of Options or Convertible
          ---------------------------------------------------------------
Securities.  If the consideration payable to, or the amount of common stock
----------
Issuable by, the Company increases or decreases, respectively, pursuant to the
terms of any outstanding Options or Convertible Securities, the Warrant Price
shall be recomputed to reflect such increase or decrease.  The recomputation
shall be made as of the time of the Issuance of the Options or Convertible
Securities.  Any changes in the Warrant Price that occurred after such Issuance
because other Additional Common Shares were Issued or deemed Issued shall also
be recomputed.

     6.   Recomputation Upon Expiration of Options or Convertible Securities.
          ------------------------------------------------------------------
The Warrant Price computed upon the original Issue of any Options or Convertible
Securities, and any subsequent adjustments based thereon, shall be recomputed
when any Options or rights of conversion under Convertible Securities expire
without having been exercised.  In the case of Convertible Securities or Options
for common stock, the Warrant Price shall be recomputed as if the only
Additional Common Shares Issued were the shares of common stock actually Issued
upon the exercise of such securities, if any, and as if the only consideration
received therefor was the consideration actually received upon the Issue,
exercise or conversion of the Options or Convertible Securities.  In the case of
Options for Convertible Securities, the Warrant Price shall be recomputed as if
the only Convertible Securities Issued were the Convertible Securities actually
Issued upon the exercise thereof, if any, and as if the only consideration
received therefor was the consideration actually received by the Company
(determined pursuant to Section 9), if any, upon the Issue of the Options for
the Convertible Securities.

     7.   Limit on Readjustments.  No readjustment of the Warrant Price pursuant
          ----------------------
to Sections 5 or 6 shall increase the Warrant Price more than the amount of any
decrease made in respect of the Issue of any Options or Convertible Securities.

     8.   30 Day Options.  In the case of any Options that expire by their terms
          --------------
not more than 30 days after the date of Issue thereof, no adjustment of the
Warrant Price shall be made until the expiration or exercise of all such
Options.

     9.   Computation of Consideration.  The consideration received by the
          ----------------------------
Company for the Issue of any Additional Common Shares shall be computed as
follows:

          (a) Cash  shall be valued at the amount of cash received by the
              ----
Corporation, excluding amounts paid or payable for accrued interest or accrued
dividends.

          (b) Property.  Property other than cash shall be computed at the fair
              --------
market value thereof at the time of the Issue as determined in good faith by the
Board of Directors of the Company.

          (c) Mixed Consideration.  The consideration for Additional common
              -------------------
Shares Issued together with other property of the Company for consideration that
covers both shall be determined in good faith by the Board of Directors.

                                       3
<PAGE>

          (d)  Options and Convertible Securities.  The consideration per
               ----------------------------------
Additional Common Share for Options and Convertible Securities shall be
determined by dividing:

               (i) the total amount, if any, received or receivable by the
Company for the Issue of the Options or Convertible Securities, plus the minimum
amount of additional consideration (as set forth in the instruments relating
thereto, without regard to any provision contained therein for a subsequent
adjustment of such consideration) payable to the Company upon exercise of the
Options or conversion of the Convertible Securities, by

               (ii) the maximum amount of common stock (as set forth in the
instruments relating thereto, without regard to any provision contained therein
for a subsequent adjustment of such number) ultimately Issuable upon the
exercise of such Options or the conversion of such Convertible Securities.

     10.  General.
          -------

          10.1 Governing Law.  This Antidilution Agreement shall be governed in
               -------------
all respects by the laws of the State of California as such laws are applied to
agreements between California residents entered into and to be performed
entirely within California.

          10.2 Successors and Assigns.  Except as otherwise expressly provided
               ----------------------
herein, the provisions hereof shall inure to the benefit of, and be binding
upon, the successors, assigns, heirs, executors and administrators of the
parties hereto.

          10.3 Entire Agreement.  Except as set forth below, this Antidilution
               ----------------
Agreement and the other documents delivered pursuant hereto constitute the full
and entire understanding and agreement between the parties with regard to the
subjects hereof and thereof.

          10.4 Notices, etc.  All notices and other communications required or
               -------------
permitted hereunder shall be in writing and shall be mailed by first class mail,
postage prepaid, certified or registered mail, return receipt requested,
addressed (a) if to Purchaser at Purchaser's address as set forth below, or at
such other address as Purchaser shall have furnished to the Company in writing,
or (b) if to the Company, at the Company's address set forth below, or at such
other address as the Company shall have furnished to the Purchaser in writing.

          10.5 Severability.  In case any provision of this Antidilution
               ------------
Agreement shall be invalid, illegal, or unenforceable, the validity, legality
and enforceability of the remaining provisions of this Antidilution Agreement
shall not in any way be affected or impaired thereby.

          10.6 Titles and Subtitles.  The titles of the sections and subsections
               --------------------
of this Agreement are for convenience of reference only and are not to be
considered in construing this Antidilution Agreement.

                                       4
<PAGE>

          10.7 Counterparts.  This Antidilution Agreement may be executed in any
               ------------
number of counterparts, each of which shall be an original, but all of which
together shall constitute one instrument.

<TABLE>
<CAPTION>
PURCHASER                                   COMPANY
<S>                                         <C>

SILICON VALLEY BANK                         Sonic Innovations, Inc.

By:  /s/ Ron Sherman                        By:  /s/ Andrew G. Rasguskus
     ----------------------------------          ---------------------------------------
Name: Ron Sherman                           Name: Andrew G. Rasguskus
      ---------------------------------           --------------------------------------
                (print)                               (print)
Title:                                      Title: Chairman of the Board, President or
                VP                                Vice President
---------------------------------------
Address: ______________________________     Address: ___________________________________
         ______________________________              ___________________________________
         ______________________________              ___________________________________
</TABLE>

                                       5