<PAGE>

                 STOCK RESTRICTION AND REGISTRATION AGREEMENT
                 --------------------------------------------

     THIS STOCK RESTRICTION AGREEMENT dated as of March 15, 2000, is by and
among Sonic Foundry, Inc., a Maryland corporation (the "Buyer") and Jan Brzeski
("Brzeski"), Jeffrey Gerst ("Gerst"), David Fife ("Fife"), and Fife Capital,
L.L.C. ("Capital") (collectively, "New Stockholders").

     WHEREAS, the Buyer, New Sonic, Inc., a Maryland corporation (sometimes "New
Sonic" and sometimes the "Surviving Corporation") which is a wholly owned
subsidiary of Buyer, and STV Communications, Inc., a Delaware corporation (the
"Company") are parties to an Agreement and Plan of Merger dated as of the date
hereof (the "Merger Agreement") pursuant to which the Company will merge with
and into New Sonic, upon the terms and conditions set forth therein (the
"Merger"); and

     WHEREAS, the New Stockholders will acquire, pursuant to the Merger, the
number of shares of common stock of the Buyer set forth on Exhibit A hereto (the
"Shares"); and

     WHEREAS, the parties desire to provide for certain restrictions and other
matters relating to the Shares;

     NOW, THEREFORE, the parties agree as follows:


                                   ARTICLE I
                                   ---------

                               TERM OF AGREEMENT
                               -----------------

     Term of Agreement.  This Agreement and the rights and obligations of the
parties under this Agreement, shall terminate on the earliest to occur of the
following: (a) one year following the closing of the Merger Agreement (the
"Closing"), or (b) immediately prior to the consummation of (i) the sale of all,
or substantially all, of the Buyer's assets or capital stock either through a
direct sale or merger, consolidation, reorganization or any other form of
business combination or acquisition in which the Buyer is the target of such
acquisition, or (ii) the sale of 50% or more of the Company's capital stock
pursuant to a "change in control" of the Buyer, provided, however, that the New
Stockholders shall at all times comply with all applicable requirements of
federal and state securities law, including Rule 144, with respect to the sale
of the Shares.


                                  ARTICLE II
                                  ----------

                              LOCK-UP PROVISIONS
                              ------------------

     Section 2.1  Lock-up Provisions.  Brzeski, Gerst, Fife, and Capital hereby
agree that, without the prior written consent of Buyer, they will not (1) offer,
pledge, sell, contract to sell,
<PAGE>

sell any option or contract to purchase, purchase any option or contract to
sell, grant any option, right or warrant to purchase, lend, or otherwise
transfer or dispose of, directly or indirectly, any Restricted Shares or (2)
enter into any swap or other arrangement that transfers to another, in whole or
in part, any of the economic consequences of ownership of the Restricted Shares.

     Section 2.2  Definition of Restricted Shares of Brzeski and Gerst.
Restricted Shares of Brzeski and Gerst shall mean all Shares acquired by Brzeski
and Gerst at the Closing, provided, however, that the amount of Shares deemed
"Restricted Shares" with respect to each of Brzeski and Gerst shall decrease
with time according to the schedule set forth below:

<TABLE>
---------------------------------------------------------------------------------------
<S>                                             <C>
Time Period                                     Amount of Restricted Shares
---------------------------------------------------------------------------------------
Until 6 months following                        All Shares acquired by each of Brzeski
Closing                                         and Gerst at the Closing
---------------------------------------------------------------------------------------
Beginning 6 months following                    90% of the Shares acquired by each of
Closing                                         Brzeski and Gerst at the Closing shall
                                                be deemed Restricted Shares.
---------------------------------------------------------------------------------------
Beginning 12 months following                   No Shares shall be deemed Restricted
Closing                                         Shares.
---------------------------------------------------------------------------------------
</TABLE>

     Section 2.3  Definition of Restricted Shares of Fife and Capital.
Restricted Shares of Fife and Capital shall mean all Shares acquired by Fife and
Capital at the Closing, provided, however, that the amount of Shares deemed
"Restricted Shares" with respect to each of Fife and Capital shall decrease with
time according to the schedule set forth below:

<TABLE>
---------------------------------------------------------------------------------------
<S>                                             <C>
Time Period                                     Amount of Restricted Shares
---------------------------------------------------------------------------------------
Until 6 months following                        All Shares acquired by each of Fife
Closing                                         and Capital at the Closing
---------------------------------------------------------------------------------------
Beginning 6 months following                    90% of the Shares acquired by each of
Closing                                         Fife and Capital at the Closing shall
                                                be deemed Restricted Shares.
---------------------------------------------------------------------------------------
Beginning 9 months following                    No Shares shall be deemed Restricted
Closing                                         Shares.
---------------------------------------------------------------------------------------
</TABLE>


     Section 2.4  Exception for Termination Without Cause.  If any New
Stockholder who becomes an employee of the Company at the Closing and/or
pursuant to Section 6.13 of the Merger Agreement is terminated from employment
from the Company without cause, then, notwithstanding the remaining provisions
of this Article II, no Shares held by such Stockholder shall be deemed
Restricted Shares.

                                       2
<PAGE>

     Section 2.5  Exception for Pro-Rata Registration.  Notwithstanding anything
herein to the contrary, no Shares which the Buyer registers, or is required to
register, under Section 4.2 hereof shall be deemed Restricted Shares.


                                  ARTICLE III
                                  -----------

                              GENERAL PROVISIONS
                              ------------------

     Section 3.1  Specific Enforcement.  Because the Shares cannot be readily
purchased or sold in the open market, the parties hereby acknowledge and agree
that they may be irreparably damaged in the event that this Agreement is not
specifically enforced.  Upon a breach or threatened breach of the terms,
covenants and/or conditions of this Agreement by any party, the other parties
shall, in addition to all other remedies, be entitled to a temporary or
permanent injunction, without showing any actual damage, and/or a decree for
specific performance, in accordance with the provisions hereof.

     Section 3.2  Legend.  All certificates evidencing any of the New
Stockholder's Shares subject to this Agreement shall also bear a legend
substantially as follows during the term of this Agreement:

          "The shares represented by this certificate are subject to
       restrictions on transfer and may not be sold, exchanged, transferred,
       pledged, hypothecated or otherwise disposed of except in accordance with
       and subject to all the terms and conditions of a certain Stock
       Restriction and Registration Agreement, a copy of which the Company will
       furnish to the holder of this certificate upon request and without
       charge."

     Section 3.3  Governing Law; Successors and Assigns.  This Agreement shall
be construed in accordance with and governed by the laws of the State of
Wisconsin and shall be binding upon the heirs, personal successor, executors,
administrators, successors and assigns of the parties.

     Section 3.4  Notices.  Notices given hereunder shall be deemed to have been
duly given (i) on the date of personal delivery or (ii) one business day
following delivery by express overnight courier service, to the party being
notified at its address set forth herein or such other address as it may
subsequently notify the other party in writing.

     Section 3.5  Entire Agreement and Amendments.  This Agreement constitutes
the entire agreement of the parties with respect to the subject matter hereof,
and may not be modified, amended or terminated except by the written consent of
the Company and by each New Stockholder who is to be bound thereby.

                                       3
<PAGE>

     Section 3.6  Waivers.  No waiver of any breach or default hereunder shall
be considered valid unless in writing, and no such waiver shall be deemed a
waiver of any subsequent breach or default of the same or similar nature.

     Section 3.7  Severability.  If any provision of this Agreement shall be
held to be illegal, invalid or unenforceable, such illegality, invalidity or
unenforceability shall attach only to such provision and shall not in any manner
affect or render illegal, invalid or unenforceable any other severable provision
of this Agreement, and this Agreement shall be carried out as if any such
illegal, invalid or unenforceable provision were not contained herein.

     Section 3.8  Counterparts.  This Agreement may be executed in one or more
counterparts, each of which shall be deemed to be an original, but all of which
taken together shall constitute one and the same instrument.


                                  ARTICLE IV
                                  ----------

                                 REGISTRATION
                                 ------------

     Section 4.1  Shelf Registration.  The Buyer shall (i) file with the
Securities and Exchange Commission (the "SEC") a registration statement for the
Shares on Form S-3 (the "Shelf Registration") within 90 days of the date of
Closing, (ii) use its best efforts to have such registration statement declared
effective with the SEC, and (iii) use its best efforts to maintain the
effectiveness of the Registration Statement for a period not less than one year
from the Closing.  Should the Shelf Registration not be declared effective or
should its effectiveness lapse for any reason during the period set forth above,
the Buyer shall use its best efforts to have the Shares registered on another
registration statement as soon as reasonably practicable.

     Section 4.2  Pro-Rata Registration.  In the event that the Buyer registers
shares of its common stock for sale by a Vice President or other employee of the
Company ("Existing Employee") at or above the level of Vice President, then the
Company shall also register Shares of the New Stockholders in the same manner as
registered with respect to such Existing Employee, if such Shares are not
already registered in such manner.  The amount of Shares to be registered with
respect to such New Stockholder shall be no less than the amount determined by
multiplying (x) if Shares of one Existing Employee are being registered, the
ratio of the number of shares being registered for such Existing Employee
divided by the total number of shares held by such Existing Employee, and if
shares of more than one Existing Employee are being registered, the highest such
ratio with respect to all Existing Employees whose shares are being registered,
and (y) the number of shares held by such New Employee.

     Section 4.3  Survival of Restrictions.  Notwithstanding any registration
pursuant to Article IV hereof, the remaining provisions of this Agreement shall
survive the registration of the Shares, as set forth herein.

                                       4
<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement.


     SONIC FOUNDRY, INC.

     By:
        ---------------------------

     Title: Chief Executive Officer
     754 Williamson Street
     Madison, WI 53703




     NEW STOCKHOLDERS


     ------------------------------
     Jan Brzeski


     ------------------------------
     Jeffrey Gerst


     ------------------------------
     David Fife



     FIFE CAPITAL, L.L.C.

     By:
        ---------------------------
     Its:
         --------------------------

                                       5