Sony MDR-NC40 Manual

Sony alkaline battery LR03/ 

AM-4 (N)

40 hours*

2

Sony battery R03/UM-4 (NU)

20 hours*

2

*

1

  1 kHz, 0.1 mW + 0.1 mW output

*

2

  Time stated above may vary, depending on the temperature or 

conditions of use.

Because the supplied battery was included in the package from 

the time of manufacture (as a convenience to the user), it is 

possible that the battery life may be somewhat depleted by the 

time of purchase. The actual life of the supplied battery may be 

shorter than the standard time described in this manual when 

using a fresh battery.

Power indicator dims, and the noise canceling function is 

deactivated. Replace the battery with a new one in this case.

 





When storing the headphones in the supplied carrying case, 

set the inner partition up, fold the headphones and store.

The plug adaptor and reserve battery can also be stored in 

the pockets of the carrying case.



 Mobile phones may cause interference and noise. To avoid 

interference, use noise canceling feature only with wireless 

transmitters turned off (Airplane Mode). Interference noise 

can also occur from nearby mobile phones. Should this occur, 

locate the headphones further away from the mobile phone.

You can fasten the battery box by its clip on a shirt pocket.

 Do not put weight or pressure on the headphones as it may 

cause the headphones to deform during long storage.

 The earpads may deteriorate due to long-term storage or 

use.

 Be careful not to catch your finger as you fold the 

headphones.

 Clean the headphones with a soft dry cloth.  

 Do not leave the jack plug dirty otherwise the sound may 

be distorted.

 Be sure to bring the headphones to the Sony dealer when 

requiring a change of earpads or repair work.

 Do not leave the headphones in a location subject to direct 

sunlight, heat or moisture.

 Do not subject the headphones to excessive shock.

 Handle the driver units carefully.

 If you fell drowsy or sick while using these headphones, 

stop use immediately.

 If headphone sound is noisy, move the battery box away 

from sources of interference, such as a radio, etc.

Avoid using headphones at high volume. Hearing experts 

advise against continuous, loud and extended play. If you 

experience a ringing in your ears, reduce the volume or 

discontinue use.

As headphones reduce outside sounds, they may cause a 

traffic accident. Also, avoid listening with your headphones 

in situations where hearing must not be impaired, for 

example, a railroad crossing, a construction site, etc.

 Check the connection of the headphones and the AV 

equipment.

 Check that the connected AV equipment is turned on.

 Turn up the volume of the connected AV equipment.

 Replace the battery.

 Turn down the volume of the connected AV equipment.

 Replace the battery.

 Move the battery box away from the connected source 

device.

Type 

Closed, dynamic

Driver unit 

30 mm, dome type (CCAW adopted)

Power handling capacity 

 

50 mW

Impedance 

68 Ω at 1 kHz (when the power is on)

 

30 Ω at 1 kHz (when the power is off)

Sensitivity 

102 dB/mW (when the power is on) 

100 dB/mW (when the power is off)

Frequency response 

 

14 Hz - 22,000 Hz

Total Noise Suppression Ratio*

1

 

Approx. 10 dB*

2

Cord 

Approx. 1.5 m (59 

1

/

8

 in) OFC litz cord 

(including battery box)

Power source 

DC 1.5 V, 1 × R03 (size AAA) battery

Mass 

Approx. 110 g (3.9 oz) including battery 

box, cord, and battery 

Approx. 80 g (2.9 oz) not including 

battery box, cord, and battery

Sony R03 (size AAA) battery (1)

Carrying case (1)

Plug adaptor for in-flight use*

3

 (single/dual) (1)

Operating Instructions (1)

*

1

  Under the Sony measurement standard.

*

2

  Equivalent to approx. 90 % reduction of energy of sound 

compared with not wearing headphones.

*

3

  May not be compatible with some in-flight music services.

Design and specifications are subject to change without 

notice.

“WALKMAN” and “WALKMAN” logo are registered 

trademarks of Sony Corporation.

Connect the headphones to the AV equipment.

 

Wear the headphones marked  in your right 

ear and the one marked  in your left ear.

Turn on the power of the headphones. 

The power indicator lights in red. The power 

switch is located on the battery box. When power 

is turned on, ambient noise is reduced, and you 

can listen to music more clearly at a lower 

volume.

Start playing on the AV equipment.

When the power switch is set to on, noise canceling can be 

deactivated while the MONITOR button is pressed so that 

you can hear ambient sound.

 The supplied plug adapter can be connected to the dual or 

stereo mini jacks in an airplane.

 Do not use the headphones when use of electronic 

equipment is prohibited or when use of personal 

headphones for in-flight music services is prohibited.

If you have any questions or problems concerning the system 

that are not covered in this manual, please consult the 

nearest Sony dealer.

Turn off the power of the headphones.
Notes
 The noise canceling function is only effective for noise in the 

low frequency band. Although noise is reduced, it is not 

canceled completely.

 Do not cover the microphone of the headphones with your 

hands. The noise canceling function may not work properly.

 The noise canceling function may not work properly unless the 

headphones are put on firmly.

 You can use the headphones even without turning on the 

power. In this case, the noise canceling function is not active, 

and the headphones operate as passive headphones.

 After you turn on the power of the headphones, you may hear 

a slight hiss. This is the operating sound of the noise canceling 

function, not a malfunction.

 In a quiet place, or depending on certain noises, you may feel 

that the noise canceling function is not effective, or that noise 

is accentuated. In this case, turn off the power of the 

headphones.

This device complies with Part 15 of the FCC Rules.  

Operation is subject to the following two conditions: (1) 

This device may not cause harmful interference, and (2) this 

device must accept any interference received, including 

interference that may cause undesired operation.
You are cautioned that any changes or modifications not 

expressly approved in this manual could void your authority 

to operate this equipment.
The validity of the CE marking is restricted to only those 

countries where it is legally enforced, mainly in the countries 

EEA (European Economic Area).

 Noise canceling headphones reduce unwanted ambient 

noise, providing a quieter environment to enhance your 

listening experience. 

 Lightweight design (less than 3 oz. for headphones 

portion) reduces stress on head.

 Soft and comfortable fit from pressure-relieving urethane 

ear cushion.

 Compact, folding design convenient for travel use.

 Compact battery box with monitor function to silence the 

audio and listen outside.

Push and slide the compartment lid on the rear 

of the battery box fully, and open. 

Before opening the compartment lid, check that 

the claws of the lid are seen.



Insert one R03 (size AAA) battery, matching the 

 on the battery to the  in the battery 

compartment.

Insert the  end first.

Close the lid.

3-282-466-33(1)

Noise Canceling 

Headphones

MDR-NC40

© 2008   Sony Corporation     Printed in Malaysia

Operating Instructions

US

Manual de instrucciones

ES