How Dogs Hear

Smell:

1. Olfactory Receptors: Dogs have an incredibly sensitive sense of smell due to their large number of olfactory receptors. While humans have around 5–6 million olfactory receptors, dogs can have anywhere from 125 million to 300 million, depending on the breed. This allows them to detect and differentiate a wide range of scents, even in very minute quantities.

2. Jacobson's Organ: Dogs possess an additional olfactory organ called the vomeronasal organ, or Jacobson's organ. This organ helps them detect pheromones and other chemical signals from other animals, especially during mating or territorial behavior.

3. Scent Discrimination: Dogs can discriminate between different odors with remarkable precision. They can follow a particular scent trail, identify specific scents, and even determine the direction from which a scent is coming.

4. Enhanced Smelling Abilities: Dogs also have a highly developed ability to sniff in short, rapid bursts, which allows them to process and analyze scents more effectively.

Taste:

1. Taste Buds: Dogs have taste buds similar to humans, but they do not have as many. While humans have around 2,000 to 10,000 taste buds, dogs have about 1,700. This is why their sense of taste is not as refined as their sense of smell.

2. Basic Taste Sensations: Dogs can perceive the basic taste sensations of sweet, sour, bitter, and salty, just like humans. However, their sensitivity to these tastes may vary from one individual to another.

3. Preference for Meat: Dogs are known for their preference for meaty flavors. This preference likely evolved from their ancestors, who were carnivores. Dogs have more taste receptors for amino acids, which are abundant in meat, than for other taste sensations.

4. Limited Sweetness Perception: Dogs have fewer taste receptors for sweetness than humans, and many dogs are not particularly drawn to sweet flavors. In fact, some substances that are sweet to humans may taste bland or unappealing to dogs.

It's important to note that a dog's sense of smell is far more important and influential in their behavior and interactions with the environment than their sense of taste. Their acute sense of smell allows them to detect scents, track trails, locate food, and identify other animals and people. This is why dogs are often used in various roles, such as search and rescue, hunting, and drug detection, where their olfactory abilities are put to good use.

THE DOG EAR ACTS LIKE AN ANTENNA

Good hearing is a crucial ability for any predator, especially for those that hunt under low light. The sound of prey can

travel a long way and is less obstructed by trees, bushes, and rocks than the sight of

it is, so a predator with fine hearing skills can easily detect the presence, distance, and direction of the prey. In canines,

this ability is markedly enhanced by a moveable outer ear. The rotation of the ear helps the dog to localize the sound source in space. Many dog breeds have floppy ears as a result of artificial

selection that may impair this ability.

Ear movement is also a good visual indicator for an observer to know what the dog is listening to. Dogs that look forward attentively at their owners but have their ears turned back may be concentrating on the sounds they are hearing rather than

watching their human companion.

DOGS EXCEL AT HIGH SOUND FREQUENCIES

It is well known that dogs’ hearing range is much broader than that of humans.

While dogs and humans are equally

equipped to hear low-frequency (deep)

sounds (~30–40 Hz), dogs’ upper hearing of high-frequency sounds (~44,000 Hz)

goes much beyond the human maximum (~18,000–20,000 Hz). This means that dogs hear rather well in the ultrasonic

range, and thus probably hear the

high-frequency vocalizations produced by small rodents such as rats or mice. The

bias toward high frequencies may be

advantageous because small prey often produce such sounds when moving