2
Cetacean Ears
DARLENE R. KETIEN
1. Introduction
Whales and dolphins are majestic, elusive, charismatic creatures that couple
exceptional grace with enormous power. These features may account for
much of humanity's enduring fascination with whales, but they are terrible
reasons for studying their auditory systems. The principal reason whale ears
are worth investigating is ... Ginger Rogers. Ginger Rogers and Fred
Astaire were a famous dance team. Mr. Astaire was renowned for his grace
and agility. What people rarely note is that Ms. Rogers not only matched
her partner step for step, she did it wearing a cumbersome gown, in high
heels, and backwards. Just as Ginger kept pace with Fred but in a different
orientation and with added burdens, whales hear as well as land mammals
but in a different medium with special acoustic burdens.
This chapter provides an overview of the anatomical foundation of whale
hearing. It takes a functional, comparative approach, emphasizing how
structures unique to peripheral auditory systems in the two extant suborders of Cetacea, the Odontoceti (toothed whales, porpoises, and dolphins)
and Mysticeti (rorquals and baleen whales) relate to the ability of a mammalian ear to hear in water. Commonalities with land mammal ears are discussed in terms of their significance for fundamental hearing mechanisms.
Anatomical specializations found across land mammal, odontocete, and
mysticete ears are discussed in terms of the role they play in determining
species-specific frequency ranges as adaptations to cross-media behaviors
and niche substructure.
The primary task of this chapter is to deconstruct whale and dolphin ears
to determine which elements are simply mammalian and which are aquatic
or devoted to special acoustic tasks. The concept that there is a significant
relationship between ear structure and hearing capacity, and that both are
related to the animal's niche, is particularly relevant for understanding
whale hearing. Analyzing how hearing capacity and auditory structures
covary in a range of species can provide important insights into fundamental hearing mechanisms that take place in the auditory periphery
43
Cetacean Ears
DARLENE R. KETIEN
1. Introduction
Whales and dolphins are majestic, elusive, charismatic creatures that couple
exceptional grace with enormous power. These features may account for
much of humanity's enduring fascination with whales, but they are terrible
reasons for studying their auditory systems. The principal reason whale ears
are worth investigating is ... Ginger Rogers. Ginger Rogers and Fred
Astaire were a famous dance team. Mr. Astaire was renowned for his grace
and agility. What people rarely note is that Ms. Rogers not only matched
her partner step for step, she did it wearing a cumbersome gown, in high
heels, and backwards. Just as Ginger kept pace with Fred but in a different
orientation and with added burdens, whales hear as well as land mammals
but in a different medium with special acoustic burdens.
This chapter provides an overview of the anatomical foundation of whale
hearing. It takes a functional, comparative approach, emphasizing how
structures unique to peripheral auditory systems in the two extant suborders of Cetacea, the Odontoceti (toothed whales, porpoises, and dolphins)
and Mysticeti (rorquals and baleen whales) relate to the ability of a mammalian ear to hear in water. Commonalities with land mammal ears are discussed in terms of their significance for fundamental hearing mechanisms.
Anatomical specializations found across land mammal, odontocete, and
mysticete ears are discussed in terms of the role they play in determining
species-specific frequency ranges as adaptations to cross-media behaviors
and niche substructure.
The primary task of this chapter is to deconstruct whale and dolphin ears
to determine which elements are simply mammalian and which are aquatic
or devoted to special acoustic tasks. The concept that there is a significant
relationship between ear structure and hearing capacity, and that both are
related to the animal's niche, is particularly relevant for understanding
whale hearing. Analyzing how hearing capacity and auditory structures
covary in a range of species can provide important insights into fundamental hearing mechanisms that take place in the auditory periphery
43