Section 68.4 - Hearing aid-compatible telephones(a)(1) Except for telephones used with public mobile services, telephones used with private radio services, and cordless and secure telephones, every telephone manufactured in the United States (other than for export) or imported for use in the United States after August 16, 1989, must be hearing aid compatible, as defined in § 68.316 . Every cordless telephone manufactured in the United States (other than for export) or imported into the United States after August 16, 1991, must be hearing aid compatible, as defined in § 68.316 .(2) Unless otherwise stated and except for telephones used with public mobile services, telephones used with private radio services and secure telephones, every telephone listed in § 68.112 must be hearing aid compatible, as defined in § 68.316 .(3) A telephone is hearing aid-compatible if it provides internal means for effective use with hearing aids that are designed to be compatible with telephones which meet established technical standards for hearing aid compatibility.(4) The Commission shall revoke or otherwise limit the exemptions of paragraph (a)((1) of this section for telephones used with public mobile services or telephones used with private radio services if it determines that(i) such revocation or limitation is in the public interest;(ii) continuation of the exemption without such revocation or limitation would have an adverse effect on hearing-impaired individuals;(iii) compliance with the requirements of § 68.4(a)(1) is technologically feasible for the telephones to which the exemption applies; and(iv) compliance with the requirements of § 68.4(a)(1) would not increase costs to such an extent that the telephones to which the exemption applies could not be successfully marketed.54 FR 21430, May 18, 1989, as amended at 55 FR 28763, July 13, 1990; 57 FR 27183, June 18, 1992; 61 FR 42186, Aug. 14, 1996