When the testimony is transcribed, the deposition shall be submitted to the witness for examination and shall be read to or by him, unless such examination and reading are waived by the witness and by the parties, which shall be entered upon the record. Any changes in form or substance which the witness desires to make shall be entered upon the deposition by the person before whom the deposition was taken or, in his absence, by the person recording the deposition with a statement of the reasons given by the witness for making them. The deposition shall then be signed by the witness, unless the parties by stipulation waive the signing or the witness is ill or cannot be found or refuses to sign. If the deposition is not signed by the witness, the reasons therefor shall be entered upon the record and the deposition may then be used for all legal purposes unless on a motion to suppress under Rule 29.4 the court holds that the reasons given for refusal to sign require rejection of the deposition in whole or in part.