Audio

HEARING AND LISTENING

Hearing and listening are not the same thing, although they are, of course, interrelated. At the risk of over simplification, we might say that hearing is a physio logical process, whereas listening is a psychological process.

Physiologically, hearing is a process in which sound waves entering the outer ear are transmitted to the cardrum, converted into mechanical vibrations in the middle ear, and changed in the inner ear into electrical impulses that travel to the brain.

The psychological process of listening begins with someone's awareness of and attention to sounds or speech patterns (receiving), proceeds through identifi cation and recognition of specific auditory signals (de coding), and ends in comprehension (understanding). 

Hearing and listening are also teaching and learning processes. As with visual communication and learning, a message is encoded by a sender and decoded by a re receiver. The quality of the encoded message is affected by the ability of the sender to express the message clearly and logically. The understandability of the decoded message is affected by the ability of the receiver to com prehend the message.

The efficiency of communication is also affected as the message passes from sender to receiver. Breakdowns in audio communications can occur at any point in the process: encoding, hearing, listening, or decoding, as il lustrated in Figure 7.3. Appropriate encoding of the message depends on the sender's skill in organizing and presenting it. For example, the vocabulary level of the message must be within the vocabulary level of the receiver.

Developing Listening Skills

Hearing is the foundation of listening. Therefore, you should first determine whether all of your stu dents can hear normally. Most school systems regu larly use speech and hearing therapists to administer audiometric hearing tests to provide the data yout need. Standardized tests also measure students' listen ing abilities. These tests are often administered by the school district, so check on the availability of listening test scores.

You can use a number of techniques to improve stu dent listening abilities:

• Guide listening. To guide their listening, give students some objectives or questions beforehand. Start with short passages and one or two objectives. Then gradually increase the length of the passage and the number and complexity of the objectives or questions.

• Give directions. Give students directions individually or as a group on audiotape. You can then evaluate students' ability to follow these instructions. With audio instructions, you can examine worksheets or products of the activity. When giving directions orally, observe the "say it only once" rule so that students place value on both your and their time and their incentive to listen is reinforced.

• Ask students to listen for main ideas, details, or inferences. Keeping the age level of the students in mind, you can present an oral passage. You can read at story and ask primary students to draw what is happening. Ask students to listen for the main idea and then write it down. Use this technique, too, when you want students to draw details and inferences from the passage. 

• Use context in listening. Younger students can learn to distinguish meanings in an auditory context by listening to sentences with words missing and then supplying the appropriate words. 

• Analyze the structure of a presentation. Ask students to outline (analyze and organize) an oral presentation. You can then determine how well they were able to discern the main ideas and to identify the subtopics. 

• Distinguish between relevant and irrelevant information. After listening to an oral presentation of information, ask students to identify the main idea and then rate (from most to least relevant) all other presented ideas. A simpler technique for elementary students is to have them identify irrelevant words in sentences or irrelevant sentences in paragraphs.

AUDIO FORMATS

Audiotapes

The major advantages of audiotape are that you can record your own tapes easily and economically, and when the content becomes outdated or no longer useful, you can erase the magnetic signal on the tape and reuse it. Tapes are not easily damaged, and they store easily. Unlike discs, broken tapes can be repaired, although not easily. 

Of course, there are limitations to magnetic tape recordings. Background noises or a mechanical hum may sometimes be recorded along with the intended material. Even a relatively low-level noise can ruin otherwise good recording. The audio device most commonly found in the classroom is the cassette tape recorder. Cassette tapes are identified according to the amount of recording time they contain. For example, a C-60 cassette can record) 60 minutes of sound using both sides (i.e., 30 minutes on each side). A C-90 can record 45 minutes on each side. Cassettes are available in various lengths. The size of the plastic cassette containing the tape is the same in all cases, and all can be played on any cassette machine. The cassette is durable; it is virtually immune to shock and abrasion. It can be snapped into and out of a recorder in seconds. It is not necessary to rewind the tape before removing it from the machine.

There are a few drawbacks to cassettes. For instance, longer tapes, particularly C-120s, sometimes become stuck or tangled in the recorder because of the thinness of the tape. If this happens, and unless the content on the tape is unique and of considerable value, you are best advised to throw the tape away. If it sticks or gets tangled in the machine once, it is likely to do so again.

Compact Disc

Physically, the compact disc (CD) looks like a small, sil ver platter. The music or other sounds are stored as dig itized bits of information (see "Close-up: How a Compact Disc Works" on page 178). The disc is only 12 centimeters (4.75 inches) in diameter, yet it stores an in credible amount of information. Current CDs contain as much as 80 minutes of music.

MP3

A new direction for audio is the ability to use your com puter and the Internet to obtain audio files. MP3 (MPEG Audio Layer 3) is an audio compression format that makes large audio files available by shrinking them into smaller files that can quickly and easily be captured on the Internet. These files are streamed audio, which means they are sent in packets to the user, giving the user an opportunity to listen to portions of the file while waiting for additional portions to download. MP3 is an "open" standard, which means it is available to anyone who has access to the Internet. Several computer pro grams that access and play MP3 audio files are free to the user; many others are available for purchase. Many of the audio files are also free. Programs also are avail able that will convert audio CD tracks to MP3 (a process known as ripping). Many portable MP3 players are now on the market as well.

PRODUCING CLASS MATERIALS

ON CASSETTE TAPES Students and teachers can easily prepare their own cas sette tapes (see "How to... Record Audiocassettes" on p. 182). Students can use cassette tapes for gathering oral histories and preparing oral book reports. The teacher can prepare tapes for use in direct instruction, as illustrated by the vocational-technical school example referred to later in this section (Figure 7.6). Skills practice, such as pronunciation of a foreign language, can also be provided by audiocassette. A popular project in 12th grade social studies classes is the recording of oral histories.

DUPLICATING AND EDITING AUDIOTAPES

It is a relatively simple procedure to duplicate an audio tape. You can duplicate your tapes by one of three methods: the acoustic method, the electronic method, and the high-speed duplicator method.

SELECTING AUDIO MATERIALS 

Before selecting your audio materials, you should have analyzed your audience and stated your objective ac cording to the ASSURE model (see Chapter 3). Then: you are ready to select, modify, or design your audio materials. Part of this process involves locating available materials and appraising them. If nothing acceptable can be found or modified, you can produce your own audiocassette tapes as described in the previous section. In selecting audio materials to use in your instruction, first determine what materials are available locally. Con sult with a media specialist to determine what is available in your media center. If appropriate materials are not available, refer to the appropriate directories (see Ap pendix C, additional information appears on the "Class room Link Portfolio" CD-ROM and on the Companion Website [http://www.prenhall.com/heinich]). Selec tion guides for music CDs include Best Rated CDs Clas sical and Best Rated CDs Jass and Pop, published annually by Peri (Voorheesville, NY).

You should preview and appraise both commercially and locally produced materials before using them with your students. You may wish to use the "Appraisal Check list: Audio Materials" to guide your selection decisions.

UTILIZING AUDIO MATERIALS

The next step after selecting or producing your audio materials is to use them with your students. The five Ps are appropriate for group use of audio materials: preview the materials, prepare the materials, prepare the environment, prepare the learners, and provide the learning experience.

REQUIRE LEARNER PARTICIPATION

Before you begin the lesson, determine how to get and keep your students actively involved. One technique is to give students a set of questions to answer during the listening. Younger learners may act out the role por trayed in the materials. Foreign language tapes may in clude pauses for learners to practice pronunciation. After listening to a story they may draw a scene from the audio description.

EVALUATE AND REVISE

Determine how effective the audio materials were. You can gather data by making observations, evaluating test. results, or discussing the experience with students. You may decide to revise how you use the materials or to modify the materials themselves.