SO: DD-3

The loudest bats use sonar as loud as 140 decibels which as loud as the Space Shuttle.

To protect themselves from being deafened by their own intense sonar sounds, bats have a special very small muscle, the stapedius muscle. It is attached to one of the three bones in the inner ear.



It has one purpose: to engage the bones of the bat’s inner ear from the rest of the inner ear as the bat makes the sonar blasts.

The stirrup bone (which looks like a horse’s stirrup) is connected to the eardrum.

Bats can send out two different types of frequencies. Scientists call one “FM” (frequency modulated) and the other “CF”(constant frequency…It is constant–it doesn’t change). CF–“one sound sonar”– is often used when the bats are scanning a large open area for insects. Powerful blasts with it do the trick in giving the bat a good bird’s eye view of what is around him.

In FM sonar, the blast contains more than one frequency of ultrasound wave. It is often used when the bats are scanning a large open area for insects.

To remember that FM frequencies are used for the capture, use these memory tricks. F can stand for Fast. When the bat needs to make Fast moves, it uses FM waves. F can also stand for Fingers. You have many Fingers and FM has more than one ultrasound wave.

</span The picture of the big FAT cochlea is a brown bat’s. Inside it are his three ear bones–the hammer, anvil and stirrup. The sonar blasts can be shot out by the bat because the stapedius muscle disengages the three ear bones while each new blast is being sent out. It then re-engages the bones in less than a 200th of a second to receive its echo! If that timing wasn’t precise to the tenths of a second, all echolocating bats on earth would go deaf and die within a day!

The fat-ness of the bat cochlea helps the Big Brown Bat to discriminate its own hIgh-frequency sonar from many other bat’s sonar.

The FM blast of sonar sound consists of several different sounds. FM means frequency modulated. Modulated means to adjust. (Look it up if you need to.)

FM sonar works perfectly for bats hunting in crowded situations like when thousands of bats encounter a swarm of insects and begin darting at high speeds around one another.

Bats’ brains can “read” ultra-sound echoes incredibly fast–about 2 to 3 thousandths of a second!

Being able to understand what their echoed sound is telling them very quickly is critical for echolocating bats to not crash into one another.

Scientists discovered that some bats can change the shape of their ears in a hundredth of a second.

Bats’ strange, spooky-looking noses have what are called nose twigs.  Scientists now believe that these noses are super-sophisticated ultrasound transmitters that change shape as the sound is traveling through them!

Many bats DNA codes for wiring the brain to seek crowded conditions.

Ribbing in bats’ ears helps channel the earwax up the ear canal.

The tendons in a bat’s foot are arranged in such a way that a bat is relaxed when their foot grabs what it is holding onto. Without this, foot muscles would keep fatiguing and it’d be routine guano-trips on the cave floor for the hanging bats!

At Bracken Cave, there’s pretty much a steady stream of bats that come out of the cave when it is time to exit. This is how they form the flying line which is the same size right as they emerge from the cave.
This means something very interesting. This means that somehow departing numbers of bats are being regulated. There’s no pushing for front-of-the-line.

The stapedius muscle is very important for bats. This muscle can disengage the ear so the ear is not damaged with its loud sonar.

The “front” of the bat cochlea is wide. High sounds are heard in this wide outer coil of the cochlea. The bat must be able to tell its high-pitched sonar from the high-pitched blasts of thousands and even hundreds of thousands of other blasts, It is this part of the cochlea that does this.

List 2 summaries of the devotional parts in this article and give a different personal application to each.