Who has the better sonar: Bat or Dolphin ?

Dolphin sonar is superior. Sound travels 4-1/3 times faster through water than through air and it also travels much farther. A ship moving off shore seems to be gliding along silently, but put your head under water and you can hear every pulse of its engine. Water can also carry much more sound than air can.

Bat echolocation uses very high pitched squeaks to find nearby flying insects and negotiate around nearby objects, but as I'm sure you know, high pitches don't carry nearly as well as low pitches. The dolphins echolocation uses much lower pitches and has much greater range.

But what really makes dolphin sonar clearly superior is its versatility. Dolphins normally broadcast their echolocation clicks in a very narrow range that covers only about 10 degrees of arc. We now know that by contracting tiny muscles around the oil-filled glands called melons in their heads, dolphins can change the focus of that sound from a 10º spread to a sharp point, like sunlight through a magnifying glass, to produce a sound so intense that it can stun or kill. We now believe that any dolphin could probably kill you if you were in the water with it just by pointing at you and whistling in a certain way. The dolphins are so careful not to misuse this power that we didn't even suspect they had such power until 1937, when some Russian scientists first proposed such a thing. The actual proof, film of a dolphin zapping a fish, didn't come until many years later.

Since some of the previous answers have been excellent, I am going to go off topic on the chance you might be interested.

Beaked whales are part of suborder odontoceti which includes dolphins and killer whales. All of the animals in the suborder emit sound pulses to probe their surroundings by active echolocation.

Their tendency to appear in large numbers on the beach in the vicinity of Navy sonar exercises have made them the subject of a lot of study by various marine institutes (particularly WHOI and Cornell University). New observations about dive patterns, biosonar performance, anaerobic metabolism, etc. are being discovered.

The beaked whale is now the world record holder for diving depth (verified by scientific analysis). Previous record holders were elephant seals and sperm whales.

It was discovered that "beaked whales" only use their echolocation sonar at the deepest part of their dives. Scientists hypothesize that the animals are afraid of being detected near the surface where they may become prey. This theory is consistent with the idea that man-made sonar may be particularly frightening to an animal that is avoiding detection.

It was also discovered that the whales were using their sonar to coordinate their dives, so that pairs of animals would stay close at water depths where there is no visibility. I don't know if they are cooperating on the hunt. Now that we know that they rely on having their companion nearby, even while hunting and foraging, it can be speculated that separation inadvertently caused by a loud man-made sound might cause a great deal of distress.

Also, the acoustic tags that are attached to beaked whales did register the echo from some prey (a squid). This is the first time that an actual echo has been recorded.

There are a number of curious unexplained phenomena in this research. Strangely long interclick intervals; very unusual dive patterns; etc.

It may be an interesting area of your research. That is assuming you are doing research.

dolphin because

Echolocation and Communication

Dolphins produce an enormous variety of sounds, up to frequencies ten times those heard by human beings. The sounds are apparently produced by a complex of anatomical structures including the blowhole with its air sacs and valves. Each dolphin has a signature whistle with which it identifies itself; a calf soon learns to recognize its mother's whistle. Clicking and rapid creaking sounds are the basis of the echolocation mechanism (sonar) with which the dolphin gathers extremely precise information about the size, location, and nature of surrounding objects. Dolphins communicate by means of a demonstrably descriptive language understood by more than one species, using all the sounds in their repertory. They are observed to converse, and it has been repeatedly shown that one animal can convey instructions to another. Computer-aided efforts are being made, so far without success, to learn the dolphin language and to teach dolphins human speech, either in its normal form or translated into whistle combinations.

I'm gonna go with dolphins. They are more intelligent and capable of a wider range of emotions. Also, they're one of like, what? The three types of animals including humans that have sex for pleasure? I'd say they're pretty hip.

Bats have sharper sonar, its sonar is three times powerful

Bats have a better echolocation because sound travels much less efficiently in air than in water.

dolphin