Audio-based instruction includes radio broadcasts; interactive radio instruction (IRI); one- and two-way audio instruction; and, increasingly, podcasts. This section examines the most prevalent forms of audio- (or aural) based learning. In the educational context both teachers and learners have been benefiting from this mode.

More than print-based instruction, audio instruction has proved to be a successful means of conveying information to teachers, particularly in areas of conflict, areas marked by difficult terrain, and remote and isolated locations. Because it is a broadcast technology, new listeners can be brought on board at very low unit costs. Furthermore, radios and audiocassette and CD players are easy-to-use, widely available technologies, even in the poorest corners of the globe.

This section mainly examines the interactivity examines two-way radio, IRI, and interactive audio instruction (IAI) as modes of distance learning.

The chapter you read from the book above describes different modes of audio and radio based instruction with a few case studies to illustrate the application of the audio/radio component integrated with other technologies and human interaction. Let us summarise each mode given in the chapter.

Two-way audio

Two-way audio provides instruction, content, and resources to students and teachers in isolated and hard-to-reach locations with little communications infrastructure. Unlike one-way audio instruction, two-way audio allows back-and-forth communication between the teacher and students by telephone talk back.

Radio broadcast

Radio-both broadcast and interactive-has been a commonly used model for distance-based instruction; primarily in terms of upgrading existing teachers' content knowledge skills. As a teacher training tool, radio is especially effective in countries where it is already a common technology; where radio listening is a primary source of entertainment and information and television is often unavailable outside the capital city; where existing radio infrastructure is present; where Internet connectivity, computers, and computer-literate teachers are in short supply; and where radio can substitute for the absence of a well-developed and widely distributed corps of teacher trainers and professional development opportunities.

The Chapter you read also describes the modes where interactivity is made available in a radio or audio presentation.

Interactive radio instruction (IRI)

More promising and better researched than broadcast radio is the impact of IRI on teacher practice. IRI is an instructional approach that uses one-way radio to reach two audiences (students and their in-class teachers).

In this dual-audience, direct-instruction approach, the teacher is not "live" but pre-recorded. Once the in-class teachers turn on the radio, the radio "teacher" delivers content and orally directs the in-class teachers to apply a variety of interactive instructional approaches within their classrooms. Both the content and activities of the radio program are based on the national curriculum and use a series of structured learning episodes in which students are prompted to sing songs, participate in individual and group work, answer questions, and perform certain learning tasks.

Regular IRI broadcasts offer curriculum developers the opportunity to scaffold instruction across a series of episodes and to model activities-such as short experiments using locally available materials-that can be completed by teachers and students between broadcasts. The approach is interactive, because the radio "teacher" speaks to the students and the students respond to radio prompts and also interact with materials and with one another at the radio instructor's prompting (Gaible and Burns 2007).

The best practices exhibited in all IRI programmes are summarised below:

1. Highly scaffolded just-in-time professional development: Radio provides structured, in class, job-embedded teacher professional development.
2. Uses formative assessment: IRI owes much of its success to the practice of continual formative evaluation. IRI programs are evaluated throughout the life cycle of the IRI project to gauge student interest, participation levels, and skills development.
3. Proven impact on teachers' instructional practices: Because of its scope, IRI can provide structured support to primary teachers throughout a country, even those in the most isolated regions.
4. Proven impact on teachers' content knowledge and content-based pedagogical knowledge: Radio instruction, both for students and adults, has proved effective in offering basic content knowledge to adults as well as children (Perraton, 1993), particularly when combined with print and supported group study.
5. Changes in teacher attitudes and dispositions: Anecdotal evidence of IRI's impact on teachers' attitudes is strong, with teachers in many programs stating that IRI has increased their motivation.