Please review information from your book the CD ROM and your notes from lecture Review Sheet CSD306K for Exam 2 Review Chapters 2 4 5 15 and 16 Page 74 Know the orientation of anatomical land marks superior posterior medial superficial The review session will be held on October 27 2013 from 8PM to 9PM proximal inferior LOOK AT CHART Hearing Know what assistive listening devices are and know the examples discussed in the Power Point slides and in your book Be able to choose which types of situations a specific assistive listening device would be best for use in The terms assistive device or assistive technology can refer to any device that helps a person with hearing loss or a voice speech or language disorder to communicate These terms often refer to devices that help a person to hear and understand what is being said more clearly or to express thoughts more easily FM systems use radio signals to transmit amplified sounds They are often used in classrooms where the instructor wears a small microphone connected to a transmitter and the student wears the receiver which is tuned to a specific frequency or channel People who have a telecoil inside their hearing aid or cochlear implant may also wear a wire around the neck called a neckloop or behind their aid or implant called a silhouette inductor to convert the signal into magnetic signals that can be picked up directly by the telecoil FM systems can transmit signals up to 300 feet and are able to be used in many public places However because radio signals are able to penetrate walls listeners in one room may need to listen to a different channel than those in another room to avoid receiving mixed signals Personal FM systems operate in the same way as larger scale systems and can be used to help people with hearing loss to follow one on one conversations Infrared systems use infrared light to transmit sound A transmitter converts sound into a light signal and beams it to a receiver that is worn by a listener The receiver decodes the infrared signal back to sound As with FM systems people whose hearing aids or cochlear implants have a telecoil may also wear a neckloop or silhouette inductor to convert the infrared signal into a magnetic signal which can be picked up through their telecoil Unlike induction loop or FM systems the infrared signal cannot pass through walls making it particularly useful in courtrooms where confidential information is often discussed and in buildings where competing signals can be a problem such as classrooms or movie theaters However infrared systems cannot be used in environments with too many competing light sources such as outdoors or in strongly lit rooms Personal amplifiers are useful in places in which the above systems are unavailable or when watching TV being outdoors or traveling in a car About the size of a cell phone these devices increase sound levels and reduce background noise for a listener Some have directional microphones that can be angled toward a speaker or other source of sound As with other ALDs the amplified sound can be picked up by a receiver that the listener is wearing either as a headset or as earbuds Alerting or alarm devices use sound light vibrations or a combination of these techniques to let someone know when a particular event is occurring Clocks and wake up alarm systems allow a person to choose to wake up to flashing lights horns or a gentle shaking Visual alert signalers monitor a variety of household devices and other sounds such as doorbells and telephones When the phone rings the visual alert signaler will be activated and will vibrate or flash a light to let people know In addition remote receivers placed around the house can alert a person from any room Portable vibrating pagers can let parents and caretakers know when a baby is crying Some baby monitoring devices analyze a baby s cry and light up a picture to indicate if the baby sounds hungry bored or sleepy For many years people with hearing loss have used text telephone or telecommunications devices called TTY or TDD machines to communicate by phone This same technology also benefits people with speech difficulties A TTY machine consists of a typewriter keyboard that displays typed conversations onto a readout panel or printed on paper Callers will either type messages to each other over the system or if a call recipient does not have a TTY machine use the national toll free telecommunications relay service at 711 to communicate Through the relay service a communications assistant serves as a bridge between two callers reading typed messages aloud to the person with hearing while transcribing what s spoken into type for the person with hearing loss With today s new electronic communication devices however TTY machines have almost become a thing of the past People can place phone calls through the telecommunications relay service using almost any device with a keypad including a laptop personal digital assistant and cell phone Text messaging has also become a popular method of communication skipping the relay service altogether Another system uses voice recognition software and an extensive library of video clips depicting American Sign Language to translate a signer s words into text or computer generated speech in real time It is also able to translate spoken words back into sign language or text Finally for people with mild to moderate hearing loss captioned telephones allow you to carry on a spoken conversation while providing a transcript of the other person s words on a readout panel or computer screen as back up Know the sequence of the steps of the audiological evaluation know what each test is measuring air conduction testing measures responses to pure tones through headphones tympanometry measures middle ear pressure and tympanic membrane mobility bone conduction directly stimulate the ear via bone conduction Know the different parts of a hearing aid and their function including the receiver microphone amplifier Transmitter transmits sound to radio waves and signals fm transmitter Electrode array The electrode array will electrically stimulate the neurons of the auditory nerve as opposed to the mechanical energy being transduced to chemical electrical as occurs with normal hearing Speech Processor The processor takes the electrical signals sent from the microphone and changes them into digital signals using 0s and 1s This is called analog to digital conversion A to D Once in digital format sound is