CRPD/C/GC/2 available in easy-to-read formats and augmentative and alternative modes and methods to persons with disabilities who use such formats, modes and methods. 22. New technologies can be used to promote the full and equal participation of persons with disabilities in society, but only if they are designed and produced in a way that ensures their accessibility. New investments, research and production should contribute to eliminating inequality, not creating new barriers. Article 9, paragraph 2 (h), therefore calls on States parties to promote the design, development, production and distribution of accessible information and communications technologies and systems at an early stage, so that these technologies and systems become accessible at minimum cost. The use of hearing enhancement systems, including ambient assistive systems to assist hearing aid and induction loop users, and passenger lifts pre-equipped to allow use by persons with disabilities during emergency building evacuations constitute just some of the examples of technological advancements in the service of accessibility. 23. Since accessibility is a precondition for persons with disabilities to live independently, as provided for in article 19 of the Convention, and to participate fully and equally in society, denial of access to the physical environment, transportation, information and communication technologies, and facilities and services open to the public should be viewed in the context of discrimination. Taking “all appropriate measures, including legislation, to modify or abolish existing laws, regulations, customs and practices that constitute discrimination against persons with disabilities” (art. 4, para. 1 (b)) constitutes the main general obligation for all States parties. “States parties shall prohibit all discrimination on the basis of disability and guarantee to persons with disabilities equal and effective legal protection against discrimination on all grounds” (art. 5, para. 2). “In order to promote equality and eliminate discrimination, States parties shall take all appropriate steps to ensure that reasonable accommodation is provided” (art. 5, para. 3). 24. A clear distinction should be drawn between the obligation to ensure access to all newly designed, built or produced objects, infrastructure, goods, products and services and the obligation to remove barriers and ensure access to the existing physical environment and existing transportation, information and communication, and services open to the general public. Another of the States parties’ general obligations is to “undertake or promote research and development of universally designed goods, services, equipment and facilities, as defined in article 2 of the Convention, which should require the minimum possible adaptation and the least cost to meet the specific needs of a person with disabilities, to promote their availability and use, and to promote universal design in the development of standards and guidelines” (art. 4, para. 1 (f)). All new objects, infrastructure, facilities, goods, products and services have to be designed in a way that makes them fully accessible for persons with disabilities, in accordance with the principles of universal design. States parties are obliged to ensure that persons with disabilities have access to the existing physical environment, transportation, information and communication and services open to the general public. However, as this obligation is to be implemented gradually, States parties should establish definite time frames and allocate adequate resources for the removal of existing barriers. Furthermore, States parties should clearly prescribe the duties of the different authorities (including regional and local authorities) and entities (including private entities) that should be carried out in order to ensure accessibility. States parties should also prescribe effective monitoring mechanisms to ensure accessibility and monitor sanctions against anyone who fails to implement accessibility standards. 25. Accessibility is related to groups, whereas reasonable accommodation is related to individuals. This means that the duty to provide accessibility is an ex ante duty. States parties therefore have the duty to provide accessibility before receiving an individual request to enter or use a place or service. States parties need to set accessibility standards, 7