Answer:

toneless

Answer	Crossword Clue
TONELESS	Not at all musical
TONELESS	Having poor sound
TONELESS	Uninflected

TONELESS	Devoid of resiliency.
TONELESS	Lacking in modulation.
TONELESS	Devoid of color.
TONELESS	Devoid of expression.
TONELESS	Lacking in expression
TONELESS	Without modulation
TONELESS	Unvaried, in a way
TONELESS	Without inflection or feeling

TONELESS	Lacking inflection
TONELESS	Like a robot's voice
TONELESS	Lacking expression
TONELESS	Without expression