bats and echolocation

To say that someone is blind as a bat is a misguided expression.

Misguided in this context means:

• inappropriate

• uncalled for

• unwise

• true

Bats use echolocation to create a perceptual map that allows them to see in the dark.

Perceptual in this context has something to do with:

• a mental image

• knowledge

• skill

• familiarity

Sound is a vibration that ripples away from its source in ________.

• waves

• circles

• a straight line

• coils

The rate at which this vibration occurs is called its ​ (a)   .

• frequency
• pitch
• echo
• wave

Humans can hear sounds at frequencies between

20 and 20,000 waves per second and don't perceive pitches outside that range.

Perceive here means:

• to notice or become aware of sth

• to understand or think of sb/sth in a particular way

• to imagine something

• to consider sth/sb as

The cartilage of the outer ear funnels the sound waves into the ear canal.

Funnel here means:

• to move or make something move through a narrow space

• a device that is wide at the top and narrow at the bottom, used for pouring liquids or powders into a small opening

• to move or make something move through a slippery space

• to push sth through a path with great pressure

A bat has to differentiate relevant information from signal clutter.

Clutter here means:

• unwanted signals

• messy signals

• simple noise

• noises in the surroundings

A bat emits chirps of varying frequency patterns.

Which one DOES NOT mean to emit?

• to produce

• to send out

• to push out

• to give off

Larger objects will reflect more intense echoes.

Which word is closest in meaning to intense in the sentence?

• very large

• very serious

• very strong

• dramatic

the bat analyzes the time delay between when it hears its chirp

and perceives the resulting echo to gauge the distance of a given object.

Gauge here means:

• to see clearly

• to hear accurately

• to measure exactly

• to calculate approximately