# data[].attributes.body
É necessário descer nas colunas do padlet (através da barra do lado direito) para conseguires visualizar todos os posts partilhados.

# data[].attributes.body
Quando acabares as tarefas da semana, podes ver estes vídeos.

# data[].attributes.attachment_link.readable_text
The auditory system is a sensory system that involves both the peripheral and central nervous system. To learn more about the auditory system requires understanding the principles of neuroscience. Check out these introductions to the nervous system and the auditory system. A more complete introduction will come from a university-level physiology or neuroscience textbook, such as this one.

All of the components of the auditory system work together to allow us to hear. The central auditory system consists of the cochlear nucleus, the superior olivary complex, the lateral lemniscus, the inferior colliculus, the medial geniculate body, and the auditory cortex. The Encyclopedia of Neuroscience Online includes articles about most components of the auditory system. In-depth information on the auditory system for the budding scientist is presented in the Springer Handbook of Auditory Research, a series of 65 books on all aspects of the auditory system, hearing, and hearing loss. These books continue to be published with new volumes coming out every year.

There are many interesting phenomena in the auditory system to explore. In the outer ear, sound is funneled by the pinna into the external auditory meatus, where it reaches the eardrum. So how does the size and shape of your ear affect what you hear? The ossicles in the middle ear sometimes freeze and are unable to conduct the vibrations from the eardrum to the cochlea. How is this hearing loss different from damage to the cochlea? The cochlea of the inner ear is complex and is the site of sensory transduction, where the mechanical signal is converted into a neural signal-but what are the molecules and channels involved in this process?

There are two types of hair cells. Inner hair cells connect to 95% of the fibers in the auditory nerve. How do inner hair cells transmit neural signals to the brain? Why are the synapses of the inner hair cells on the dendrites of the spiral ganglion cells among the fastest synapses in the nervous system? There are three times more outer hair cells than inner hair cells. Why do outer hair cells move up and down like little muscles during sound stimulation?

The auditory vestibular nerve, otherwise known as the eighth cranial nerve, sends signals from the hair cells to the cochlear nucleus in the brain. However, at the cochlear nucleus, many neural circuits begin to carry different types of information. Sound localization requires binaural sound stimulation with two ears. How does information from the two ears get combined and compared in the superior olivary complex so that we can localize sound? Why are the largest synapses in the brain found in the cochlear nucleus and superior olivary complex? Are there brain circuits that tell us what a sound is instead of where a sound source is located?

The inferior colliculus receives information from almost every part of the auditory brainstem, including the cochlear nucleus and superior olivary complex. This answers certain aspects of the what and some of the where, so how does it integrate all this information? There are multiple core auditory cortical areas surround by a belt of other auditory cortical areas. How is the information related to what and where distributed amongst the areas of auditory cortex?

When we have a hearing loss, it impairs our ability to communicate with others even when we are not deaf. However, some hearing loss is gradual and not noticed at first. This may be especially true for noise-induced hearing loss if we have chronic exposure to moderately loud sound, as opposed to extremely loud sound. Find out more about noise-induced hearing loss here.

Many people have a ringing in their ears called tinnitus, which never stops-even when there is no sound. This is a symptom rather than a disease. There may be many causes of tinnitus; exposure to loud sound may be among the most common causes. However, we are still not clear about what happens in the auditory system and how to cure the problem. Find out more about tinnitus here.

# data[].attributes.attachment_link.title
The science of hearing - Douglas L. Oliver

# data[].attributes.attachment_link.description
The ability to recognize sounds and identify their location is possible thanks to the auditory system. That's comprised of two main parts: the ear, and the brain. The ear's task is to convert sound energy into neural signals; the brain's is to receive and process the information those signals contain.

# data[].attributes.body
1. Lê, com atenção, as seguintes páginas do manual: pág. 162 à 168.

# data[].attributes.body
2. Visualiza e explora esta apresentação com as ideias principais dos conteúdos lidos.

# data[].attributes.body
3. Visualiza o vídeo para entenderes melhor a reflexão do som, o eco e a reverberação.

# data[].attributes.body
4. Resolve os exercícios das páginas 169 e 170.

# data[].attributes.body
5. Responde ao questionário de acordo com os exercícios que resolveste.

# data[].attributes.body
joana.almeida@aegmmaia.pt

# data[].attributes.body
Neste espaço podes partilhar dúvidas que tenhas sobre as tarefas atribuídas.

# data[].attributes.body
Neste espaço a professora apresentará uma grelha com as tarefas que cada aluno vai realizando ao longo do tempo e a respectiva nota.

# data[].attributes.attachment_link.readable_text
Marine mammal sounds provided by the Scripps Whale Acoustics Laboratory and NOAA/NEFSC.

Want to learn more and hear more dolphin and whale sounds? Explore Voices in the Sea.

Of the over 80 known species of whales and dolphins, cumulatively known as cetaceans, only some species of baleen whales produce songs. These songs have specific structures to them: units are compiled into phrases, which are ordered into themes, and repeated to form complex songs. Listen to some of them at this link.

As far as we know, only males sing. The ultimate purpose of whale song remains a mystery, although scientists have suggested some likely explanations: whale songs might be used to attract females while at breeding grounds, or to deter other males from breeding or feeding sites. Whale songs might also be used for orientation during migration, or as a display of social status to other whales. Regardless, whale songs are certainly an important aspect of the lives of marine mammals, as vocalizations are the most efficient signals transmitted in the dark, murky ocean.

Another mystery surrounding whale songs is how they physically produce sounds. Unlike humans, the trachea and nasal passage of whales are completely separate, and whales do not have vocal cords. The biggest factors inhibiting our understanding of how these animals produce songs are that we cannot keep them in captivity due to their massive size and we cannot monitor their internal organs while they are still alive. But, anatomists that work with dead, beached whales have shed some light onto the subject by identifying the U-Fold: a flap of skin over which air passes to create vibrations, similar to how our vocal cords work. While it is nearly impossible to confirm that this is the function of the U-Fold, it is a highly likely theory and the best developed to date. Read more about it here. Here is a visualization of where the U-Fold is positioned and how vibrations from it are amplified through the laryngeal sacs to produce loud, ocean-spanning songs.

Scientists have developed technologies to listen to whale songs underwater in order to investigate their purpose and track the whales for conservation. Hydrophones, or specialized underwater microphones, are used to record marine mammal sounds all over the world. These sounds are then turned into images, called spectrograms, which visualize vocalization patterns. Here are some great examples of the different sounds marine mammals make (songs or otherwise), and what they look like as spectrograms. Each marine mammal makes distinct sounds, which appear as unique spectrogram markings, making species identification from sound files easy and effective.

Once scientists have recorded marine mammal vocalizations, they can use the timing and location of the sounds to understand where marine mammals are going and when. By developing a thorough understanding of the migration routes and key habitats used by marine mammals (particularly those that are endangered), we can protect them with greater accuracy. Marine Protected Areas with restrictions on shipping speed and density can be developed based on acoustics to limit dangerous encounters of whales with ships (including lethal vessel strikes/collisions and masking of communication from shipping noise). For example, here is a case study of how acoustic tracking was used to study endangered North Atlantic right whales.

Using whale songs as a conservation tool is particularly effective because people love to connect with animals that communicate with complexity equal to that of humans. Many organizations provide followers with live transmissions of whale songs in order to inspire audiences and encourage the protection of our oceans. For instance, livewhales.com is a program that distributes humpback whale songs recorded live off of the Hawaiian coast from January through March. Whale songs spark our imagination and bring together a global community of conservation-minded individuals dedicated to protecting the oceans and their musically inclined inhabitants.

Special thanks to Reidenberg, Joy S., and Jeffrey T. Laitman. "Discovery of a low frequency sound source in Mysticeti (baleen whales): anatomical establishment of a vocal fold homolog." The Anatomical Record 290.6 (2007): 745-759.

Looking for more lessons on whales? Try these from TED-Ed:
How whales breathe, communicate ... and fart with their faces by Joy Reidenberg
Why are blue whales so enormous? by Asha de Vos

# data[].attributes.attachment_link.title
Why do whales sing? - Stephanie Sardelis

# data[].attributes.attachment_link.description
Communicating underwater is challenging. Light and odors don't travel well, but sound moves about four times faster in water than in air - which means marine mammals often use sounds to communicate. The most famous of these underwater vocalizations is undoubtedly the whale song. Stephanie Sardelis decodes the evocative melodies composed by the world's largest mammals.

# data[].attributes.body
Não te esqueças de te identificares sempre que participares no padlet.

# data[].attributes.body
Gostava que vocês voltassem a responder ao questionário de modo a melhorarem os vossos resultados.

Os alunos que têm os resultado do questionário a vermelho (ver a grelha em excel) devem voltar a repetir obrigatoriamente esse questionário.

Os  outros alunos que queiram repetir voluntariamente para melhorar a nota também o podem fazer.
BOM TRABALHO!

# data[].attributes.headline
Video - Diferença entre reflexão, absorção e refração do som

# data[].attributes.subject
Video - Diferença entre reflexão, absorção e refração do som